DIY Sous Vide Heating Immersion Circulator for About $75
DIY Sous Vide Heating Immersion Circulator for About $75

DIY Sous Vide Heating Immersion Circulator for About $75


I’ve recently been fascinated by the idea of sous vide cooking – a method of slowly cooking vacu-sealed foods in a precisely controlled water bath to achieve the optimal doneness.  Last year, Sur La Table started carrying the world’s first “home” sous vide cooker, the SousVide Supreme.  This was fantastic, since commercial sous vide cooking machines cost north of $2000.  However, the home model (priced at $450) is still a steep investment for something that essentially just keeps water warm.  I was determined that I could build a better device on-the-cheap.

Behold, the $75 DIY sous vide heating immersion circulator!  By scrapping together parts that are readily available on eBay and Amazon, I was able to build a self-contained device that heats and circulates water while maintaining a temperature accurate to .1 degree Celsius (yes, point one degrees!).  And unlike the SousVide Supreme, my device can be mounted onto any container (up to a reasonable size, perhaps 15 gallons) allowing you more room to cook, if needed.

To build your own device, you’ll need some basic soldering skills, the list of stuff below, about 6 hours of free time (plus time for glue to dry) and the can-do attitude of a geek who doesn’t want to pay $450 for a water heater.  Click the “more” link for complete step-by-step instructions.

If these instructions have helped you build you own machine, I hope you’ll consider donating.  My goal is to mass-produce the world’s first sous vide heating immersion circulator for under $100, and every donation helps!

Update: Along with my business partners, I’ve finally commercialized a home sous vide machine!  It’s called the Sansaire, and it’s available for pre-order now!
Sansaire $199 Sous Vide Machine

DSC_0050 DSC_0046

Makes: 1 sous vide immersion heater
Total tinker time: about 6 hours

Shopping list:

Note: Make sure the controller you purchase has an SSR or Voltage output.  Controllers with a relay-only output will require an external relay and different wiring than what is listed in this project.

I’ve updated the parts list to specify an SSR – it adds a little to the cost of the project, but it is far more reliable, easier to connect, and works with any SSR/Voltage-output PID controller.

  • 1 piece of 1/4” acrylic, about 5cm x 20cm
  • 1/4” x 2” eye bolt and nut
  • About 2’ of 16-18 gauge wire
  • 3 wire nuts
  • Electrical tape
  • A means of cutting acrylic (see article)
  • Soldering iron and solder
  • Multimeter (tool that measures voltage, current, resistance)
  • Hobby knife (X-Acto or similar)
  • Tub and Tile Silicone Caulk
  • Hot glue gun
  • Krazy Glue

Step 1 – Making cutouts in your enclosure

This is the most difficult part of the whole project.  In order for the final assembly to be sturdy, water-resistant and decent looking, you’ll need to cut your mounting holes as precisely as possible.  I am very lucky to have access to a laser cutter at a lab at work, which makes this kind of precision cutting very easy and accurate.  However, in the absence of a $30K computerized laser cutting machine, with a steady hand, you can achieve the same results using a high-speed rotary tool like a Dremel.

I’ve included a cutting template that is matched to the heaters, PID controller and switch in the shopping list.  However, if you use different parts (different models, different manufacturers) you’ll need to adjust the template to ensure a tight fit of all parts.

image Click here for the 1:1 scale diagram (PDF)

  1. Pick a side of the storage container that you want to be the bottom.  Using the template as a guide, cut out the three holes for the immersion heaters.  Make sure that these holes are closest to the open end of the container (the end that has the lid) to ensure you’ll be able to reach inside later for wiring, etc.
  2. Next, cut the small oval-shaped hole for the water pump power cord.
  3. Turn the container over so the side with the holes is facing down.  Now, cut out the openings for the PID controller, the on-off switch, and the power cord.  Be sure that the hole for the PID controller is towards the top.  Otherwise, you’ll be cramped for space when trying to reach the back of the controller.
  4. Next, dry-fit all of the parts to ensure a good, snug fit.  The tighter the fit, the more sturdy the finished product will be. IMG_0441

Step 2 – Making the mounting bracket and pump holder

The mounting bracket is a J-shaped piece of acrylic that will let you attach the finished sous vide cooker to the side of a pot or basin.

  1. Cut out the rectangle on the 2nd page of the parts diagram and drill the hole as indicated.
  2. Find a rectangular surface that will allow you to make the 2 90-degree bends necessary to shape the acrylic into a “J”.  I used a small, glass olive oil bottle with flat sides and rounded corners.
  3. Turn on your stove.  Holding the long end of the acrylic with an oven mitt, warm it a few inches above your stovetop, turning to heat both sides.  It may take a few minutes for the acrylic to be warm enough to bend- you’ll know you’re getting close when the acrylic starts to curl away from the heat.
  4. Bend the acrylic along (approximately) the lines indicated in the diagram to form a “J”.  Press the bottom part of the J (not the side with the hole, and not the long side) against a flat surface such as your counter top.  Immediately cool the acrylic with cool water to hold its form.

Step 3 – Mounting the immersion heaters

The immersion heaters are the primary working element of the sous vide machine.  We’ll mount them hanging down from the bottom of the enclosure, and arranged so that the opening in the middle of the coil is lined up between all three heaters.

  1. Cut the power cord off of each heater, leaving about a 4” tail of wires from the heating end.  Keep one of the long lengths of power cord (including the plug) to use later as the main power cord.
  2. Using your hobby knife, scrape down the flat sides of the heater handles to remove lettering and to flatten out the circular rim at the top of the handle.  This will allow for a deeper and tighter fit in the heater openings.
  3. Arrange all three heaters in their respective openings.  Note that the heaters should be oriented such that the coils are facing towards the center-line of the enclosure.  You should be able to fit your finger down the middle of all three coils.  Make sure the heaters are snug in their openings. IMG_0449
  4. Apply a small bead of tub and tile caulk around the heaters on the outside of the enclosure.  Allow to dry overnight before proceeding.

Step 4 – Wiring

CAUTION: Don’t ever power on the heater coils unless they are submerged in water!  Also, don’t electrocute yourself.

If you have experience with basic circuitry and wiring, this will be pretty easy.  However, if you’ve never worked with a soldering iron or circuit diagrams, these steps will take you a while.  Refer to the wiring diagram below for the “big picture.”

Wiring diagram for JLD612 PID Controller with SSR

sous vide electrical diagram for LJD612 PID

Wiring Diagram for CD101 PID Controller with physical relay

Update: I’ve updated the wiring diagram to make it clear that the view of the relay posts is from below.  In other words, if you set the relay down on your table with the pins facing up, that will match the alignment in the wiring diagram.

circuit diagram


  1. Strip off about 1/4” of shielding from your power cord (remember, the cord that you saved from one of the immersion heaters?).  Run the power cord in through the power cord opening on the front of the enclosure.  Separate the 2 wires about 6”.  One of these wires will go through the power switch, and the other will go directly to the PID controller, heaters and pump.
  2. Use your multimeter to find the two posts on the back of the power switch that are normally open, but closed when the switch is on.  On my power switch, these were the far and middle posts (not the two posts closest to the “ON” side of the switch, you know, with the dot).  IMG_0457
  3. Pass the switch mounting nut (the thing that screws on the back) over one lead from the power cable, inside the enclosure.  Run the lead out through the power switch hole.  Solder that lead to one of the posts you identified in step 2.  Cut an 8” length of wire and solder one end to the 2nd lead on the switch.  Tuck the wires inside the enclosure, place the switch in its hole, and tighten the mounding nut to secure it in place.  You’re now done with the power switch.
  4. Next, wire together the heater leads.  Separate the leads from the heating coils.  Gather together one lead from each coil to make two bundles of three.  Cut two 6” lengths of wire and add one to each bundle.  You should now have two bundles, each with four wires – 3 of which go to the heaters, and one left dangling.  Solder the wires in each bundle together, then cap with a wire nut and some electrical tape.
  5. Of the leads you have coming out of the heater bundles, one will go straight to the incoming power, and the other will go to the relay that turns on and off the heaters.
  6. At this point, it gets too difficult to describe the rest of the wiring in words, so refer to the wiring diagram.  Just make sure to be aware of how everything will mount in the enclosure when you’re all done.  Pass the wires through the mounting ring on of the PID controller before attaching them to the terminals, etc.
  7. After wiring the connections to the relay (or SSR), coat the bottom with hot glue to surround the connection points.  This will act as an insulator and prevent the relay from shorting out against any metal inside the case.  Or, if your SSR came with a plastic cover, secure it in place to prevent the connections from shorting.
  8. If you are using the PT100 thermocouple (which I recommend), make sure you connect the leads exactly as shown in the wiring diagram or you will have an inaccurate temperature reading.  (There’s no instruction manual with these probes, so it took 30 minutes of trying different combinations before I found the right one).

Step 5 – Final Assembly

  1. Using Krazy Glue, glue the J clamp to the bottom-front of the enclosure.  Wait until dry before proceeding.
    Note: This glue joint is a popular point of failure.  If you’d like, strengthen the connection between the J clamp and the body by using two screws and nuts.
  2. Glue the nut for the eye bolt to the inside of the hole in the J clamp.  Ensure that the nut lines up with the hole so the eye bolt can pass through.
    eye bolt
  3. Seal the openings for the power cord and pump cord using tub and tile caulk.
  4. Put the back cover on the enclosure and wrap the seam with electrical tape.
  5. Stick the suction cup feet of the immersion pump to the flat end of the J clamp and position the water outlet to pump through the middle of the heating coils.DSC_0039

Step 6 – Testing

Now that everything is wired up and assembled, you probably want to see if it works.  WAIT!  Don’t turn the machine on (ever!) unless the coils are submerged in water or, they will burn out in about 5 seconds (I learned this the hard way).  DSC_0038
To test the machine out, fill a basin with water so that it covers at least the coil part of the heaters.   Mount the machine on the edge, so that the J clamp hangs over the lip.  Tighten the eye bolt to secure the machine.  Plug in the cord and flip the power switch!  If the PID controller turns on and the pump starts pumping, that’s a good sign!  Note that the heaters may not warm up just yet, depending on what the target temperature is by default.

Step 7 – Programming the PID Controller

For users of the JLD612 PID Controller

For programming instructions such as running Auto-tune and changing alarm values, refer to the JLD612 manual.  Here are the steps you should take when programming your controller for the first time.

  1. Press SET and enter code 0089, then press SET.
  2. Set the value of Inty to Pt10.0 to get the temperature to display with one decimal place.  (I had to set it to Pt100, then back to Pt10.0 to get this to work the first time.
  3. Select End to exit the programming menu.


For users of the CD101 PID Controller

Out-of-the-box, the PID controller is designed to work with a different type of thermocouple, so the readings that you get using a PT100 will be strange.  Follow the instructions in this manual (that doesn’t ship with the PID controller) to set it for the PT100 probe.  You can also follow the instructions there to set the number of decimal points of precision.

Next, set a target temperature by tapping the SET button, then using the up and down arrows to pick a number and pressing SET again to confirm.  50C is a good target temp.  The OUT1 light will light up, indicating that the PID controller is turning on the heater.  You should hear a soft clicking noise – this is the relay kicking in.  At this point, the heating coils are on and warming up.  As the temperature measured by the probe (green, top line) approaches the target value (orange, 2nd line), the relay will click on and off more frequently to sustain the temperature.. DSC_0040

Ideas, Improvements, Thoughts

After burning out my first set of heating coils, I realized that there must be a better method of heating the water.  The coils are very effective and heat the water very quickly.  However, I’m pretty paranoid about burning them out again, and they’re a pain to replace.  I’ve found some commercial immersion heating elements, but they’re about $100, which inflates the budget for this project by quite a bit.  I may try using the heating element and pump system from an old espresso machine, the kind that makes steam.  Since it already has a self-contained heater and an pump, it might even be cheaper than the heating coils and aquarium pump.

I’ve also thought about turning this machine into a general-purpose temperature control unit.   Instead of wiring the heaters directly to the relay, I would install a power outlet on the back of the enclosure and add a jack to plug in an external temperature probe.  If I wanted to use the immersion heaters, I’d just plug them in to the power outlet.  If one got fried, I’m only out $6 instead of an hour of removing glue and solder.  Also, a general-purpose temperature controller is great for making your own smoker box.  A-la Alton Brown, you can plug in a hotplate filled with wood chips and have a precisely temperature-controlled smoker for just a few bucks.

I’m thrilled to start playing with sous vide cooking, and I’m happy that I was able to build an accurate, reliable machine for $75.  Even the PID Controller + Crockpot method costs $185 (not including the Crockpot!).


I gotten a lot of emails and comments asking for troubleshooting help, and rightfully so – there’s a lot going on in this project, especially if you’re pretty new to DIY electronics.  I’ve decided to add my basic troubleshooting routine, which should hopefully get you sorted out.  If you still have problems, please post a comment below, or send me an email at

If your heaters don’t get hot when they should (i.e., your machine isn’t working), do the following:

  1. Ensure that your OUT1 light goes on and off when it should.  It should be on when the unit is heating, and off when you’re at or above the set value.  If not, double check that you’ve set your temperature probe type correctly, and that OUT1 is set to heating mode in the PID settings menu.  If this looks correct, proceed to step 2.
  2. Verify that your PID controller has an SSR/Voltage output.  This should be specified on the sticker on the side of your PID controller.  The controller in the photo below only has a relay output (this is not what you want).
    relay only controller
    PID controllers generally have two types of outputs: relay and voltage.  Contrary to how it sounds, a relay output is not used for controlling a relay.  Rather, a PID controller with a relay output actually has an internal relay.  Unfortunately, the internal relay is typically not rated for the kind of load that the heating coils pull, so you cannot connect them directly to the internal relay.  A PID controller with an SSR/voltage output produces a DC voltage (8-12V DC) that we can use to control an external mechanical relay or a solid state relay (SSR).  That’s what we want.
    Telltale signs that your PID controller has a relay-only output: a) there’s no voltage across pins 5&6 (or the corresponding pins on your controller) when the OUT1 light is on, b) you hear a clicking sound when OUT1 turns on and off, even when your external (blue) relay is disconnected, and c) you measure continuity across the pins that correspond to OUT1 when OUT1 is on.
    If you have a PID controller with a relay output, not all is lost.  You’ve got two options:
    1)  Return it for a PID controller with an SSR/voltage output, or
    2)  Use the internal relay to control an external 120VAC relay that is rated for 8+ Amps @ 120VAC.  The wiring for this configuration is a little messier, and you’ll need to buy a different relay than the one specified in the parts list.  The wiring diagram for this configuration is below.  Note that I haven’t attempted to show the actual pin configuration of the external relay – rather this is the logical way you’ll need to wire it in.
    circuit diagram for relay-out
    If you’re sure that your PID controller has an SSR/voltage output, proceed to step 3.
  3. Verify that you are using the right kind of relay for your PID controller. The CD101 will work with either an SSR (solid state relay) or a physical relay. However, the JLD612 and many other PID controllers will only work with an SSR.
  4. If you’re using a CD101 and a physical relay, ensure that your external (blue) relay is wired correctly.  You should hear a clicking noise coming from that relay when OUT1 lights up or turns off.  If not, you may have connected the leads from pins 5 & 6 backwards, or your external relay may require a higher activation voltage than what your PID controller outputs.  Measure the voltage from pins 5 & 6 and compare to the coil voltage specified by your relay.  In practice, there is some wiggle room (ex., a relay with a 9V coil will often be activated by less than 9V).  If the PID doesn’t produce enough voltage, buy an SSR.  If your relay is clicking, proceed to step 5.
  5. Check for 120VAC going to the heater leads when OUT1 is on.  If you’re not seeing a voltage, check the connections across your relay and between pin 1 and your heaters.  If you’re getting 120VAC to your heater bundles, proceed to step 6.
  6. Your heaters are likely burnt out.  This can happen in a flash if you accidentally supply power to the heaters when they are out of water.  Double check by submerging your heaters and connecting an 120VAC power source directly to the leads (exercising great caution not to electrocute yourself).  If they heat up, you’ve got a loose wire somewhere in your connections.  If they don’t heat up, they’re burnt out and you’ll need to replace them.

If these instructions have helped you build you own machine, I hope you’ll consider donating.  My goal is to mass-produce the world’s first sous vide heating immersion circulator for under $100, and every donation helps!


  1. The microwave technique looks cook and is certainly more convienient. But if his microwave is anything like mine, it has cold spots and warm spots. So there’s a risk of scorching one part of your veggies and leaving the rest undercooked.

  2. Yish

    First of all, love the article. Great timing as I was just about to start on my own sous-vide setup. This will save me a lot of money over my current plans. I assume one could use the PID/thermocouple directly with a rice cooker/crockpot if you already have one of those correct?

    What do you think about using the following as the heating element. 2x the price but has the advantage of being a single unit, same net wattage, designed for large volumes of water, and could be more reliable?

  3. Simon, I’m so glad to hear that you’re planning to try this out! I’ve converted the scale drawings to SVGs to make them easier to use with the laser cutter at Metrix. You can download a zip of the files here:

    Yish, I looked at this heater too, but after I had already committed to using the immersion coils. It does look like it would do a better job and would be more rugged (and you wouldn’t have to worry about accidentally burning it out). If you decide to order one, I’d love to hear your impressions! Perhaps that heater will be a good investment for version 2.

  4. Hi Jean-Francois,
    I compared the temperature reading on the machine to three other thermometers that I have and know to be accurate. You can also verify the accuracy of the temperature by measuring the temp of boiling water (which should always be 100C) and very cold ice water (which should be close to 0C). The PID controller allows you to specify a correction factor if the thermocouple is reading an innacurate measurement.

    I let the machine run for about 45 minutes once it had brought the water to 50C. I monitored the temperature reading and it never deviated during those 45 minutes, even by .1C.

    The PID controller has an “Autotune” mode that I ran before my test. This mode turns on and off the heaters and measures the temperature change from heating and cooling. Based on the measured change, the PID controller optimizes itself automatically so that it can maintain an exact temperature. Pretty neat stuff!

  5. Just out of curiosity, at what temperature would the pump start having problems? I’m currently using a PID on a crockpot, and do 8 hour cooks at 180F for duck confit. I’d be worried about the pump operating at that temperature.

  6. muss

    I have been thinking hard about this all day and i keep coming back to a small replacement hot water heater element…they are cheap, around the same as three of the tea cup heaters, a possibility? only one round hole to cut (much easier) and it is threaded and has a gasket.

  7. WOW. Incredible stuff mate. Truly unique I have to say! I have never considered making an immersion circulator, but now feel like I have to! Talk about a cost saving too – I cannot believe how cheaply you were able to build this!! (Heck mate, you should start making them for us Seattle food people!)

  8. Hi Speckle,
    I know of a few Seattle restaurants, like Tilth and Spur, that use the sous vide method for several of their dishes, but I suspect that there are many more out there. I’m still pretty new to the technique myself, but I’m dying to explore the frontiers that it opens up in the kitchen.

    As far as what foods to choose to cook sous vide, the classic examples are fish, beef, and eggs. In all three cases, the precise control over temperature allows you to achieve a perfect doneness. I’ve eaten sous vide vegetables, like beets and carrots, but the difference isn’t nearly as dramatic.

    I just ordered Thomas Keller’s sous vide cookbook, so I’ll be sure to post my findings!

  9. alvin schultz

    I’ve gathered almost all the parts on your list…just waiting on my PT100 Thermocouple to come in…hopefully tomorrow.

    Interested in the idea of wiring the 120v outlet onto the unit instead of hardwiring the immersion heaters…would you just use a standard style plug like this:
    or did you have something else in mind?
    Is there any concern around the need to plug a 3 outlet adapter into this to accommodate all 3 heaters? I suppose it’s all the same as hardwiring them, but my electrical knowledge is very meager.

    Also, I would like to use a switch like this:
    I remember i used to have one in my car, but i don’t know how to get it to work…relay? Can you provide a wiring guide for that? Maybe this will work…

    Also is 6a 125VAC the minimum switch rating you recommend, Radioshack has a 5a 125VAC that I think i can get a “rocket switch” cover for…they’re just cool.

  10. Hi Alvin,

    Glad to hear you’re going to take on the challenge of building your own immersion circulator! If you’re going to put in an outlet (or three), I’d recommend 2 things: 1) use an outlet that is designed for outdoor use or use in damp areas, and 2) use an outlet with a built-in GFI (ground fault interrupt). You’ll know if it has GFI because there will be a small reset button built right into the face of the outlet.

    And, of course, be careful. There’s a lot of power resting a few inches above a big pool of water. I’m not sure what I need to write (legally) to make sure I’m off the hook if you shock yourself, but consider yourself warned 🙂

    As far as the switches, you should be fine with either one. The Radio Shack website doesn’t have wiring diagrams, but they’ll wire in in just about the same way as the switch I used. You can use a multimeter to test which posts to solder to – when the switch is off, there should be no electrical connection across 2 of the posts. When it is on, those two posts will pass current.

    Best of luck, and report back when you’re done!


  11. alvin schultz

    Thanks for the quick response Scott…
    No PT100 today, so I guess i have a bit more time to plan.

    had the same thought of the danger in the design. I thought about building some type of legged platform for the ddevice to rest on rather than the clamp…i suppose that with the outlet it wouldn’t have to be on top of the container and it could be next to it instead…

    for the plug in temp probe were you just thinking of using some type of TRS connector?

    Saw your steak pic, have you used yours for anything else? what type of heat (if any) does the box itself create?

  12. @alvin, Yeah, I was thinking about a TRS style connector… maybe something designed for moisture & corrosion resistance. As for the enclosure, it doesn’t generate any noticable heat. You’ll want to make sure all of your holes on the underside of the box are well sealed with caulk, though, since the basin will give off a fair amount of steam.

    So far, I’ve stuck with steak (life changing!) but I’m going to play around with other things as well. Just got Thomas Keller’s “Under Pressure” sous vide cookbook which has amazing recipes.

  13. Dan Tran


    I am currently working on a version myself but I think I should scrap it in favor of something similar to yours.

    For some reason I felt that the heating element and the circulating element should be in one system. I pumped water through some copper coiling around the heating element from a hairdryer. It works but the heating and control is too inconsistent. Not to mention, it wasn’t throttling water enough.

  14. alvin schultz

    Hi Scott,
    Can you please post the settings on you PID?

    I am sooooo close i can taste it. When my “OUT1” light comes on, i hear clicking (from the PID controller) but i get no reading on terminals 5/6.

    Also, should I expect continuity on the coil terminals of the mini-relay? i get no tone on them right now.

    Thanks for your help!

  15. Jon Trickey

    Thanks for your work pioneering this DIY project. I recently became interested in this cooking style, but I didn’t want to spend a lot of money on a dedicated cooker and I am always interested in DIY projects. I designed mine a little differently. I wanted to have plugs so that I could easily change heating elements or just use a slow cooker. I use an old crock pot last night for my first test and it worked well.
    I ended up with a slightly different PID than you did. The link you have for it did not come up with anything but I found some on E-Bay that looked the same. The one I got is the same model – CD101, but is configured differently and it came with a thermocouple. My PID has a relay built in instead of a 12v trigger on pins 5 and 6. Of course I didn’t realize this until I had already bought the relay. Mine also came with a 4 page instruction manual, but the manual leaves out how to change the parameters. My PID also has some different parameters, and I cannot change the number of decimals it displays, so it is stuck with 0 decimals.
    I wanted to keep it easy to start with, so I just took an 8 foot extension cord I had around with 3 outlets and cut it in half. I wired it into the PID so it controls the 3 outlets. It really could not be any simpler.
    The thermocouple it came with is really stubby, maybe half inch but seems to measure accurately. I had already order the probe that you used before I realized that the PID came with one, so I will probably change to that probe when it gets here.
    The only issue I have right now is the reading from the thermocouple (PV) drops 3-4 degrees every time out1 goes off. I think there must be some kind of electrical interference and I’ll play around with it to fix it. My instructions talk about twisting the power leads and minimizing the distance to avoid interference. It also says that you need to have a 250 ohm resistor on the input which I do not currently have.

    Avlin – it sounds like you have the same kind of controller as me, with the relay built in if you hear clicking. To test, take a volt meter and see if you get any voltage across pins 5-6 with out1 light. If not, then test for continuity between pins 4-5-6. Pins 4-6 should have continuity with out1 off, pins 4-5 should with out1 on. Let me know if you need help wiring it.

    I would love to hear more about what heating coils you have used that seem to last. I plan on experimenting with those next.

  16. alvin schultz

    @Jon: Yes! That worked…mine also has the built-in relay…wiring hot from the main switch on the box to #4 and out on #5 to my GFCI socket…some fine tuning and i think it’s steak for dinner tonight. I hope to finish a write up soon of my process and i will try to include some instructions on how to set accuracy and move the decimal place. I think i used Scott’s instruction link to move the decimal, but i was flipping through so many resources i may not have…

  17. @Jon Nice, I’d love to see your solution! I may build a second, general purpose unit with outlets to make a DIY smoker or a chocolate tempering machine. For my heating coils, I’m still using the 3 immersion heaters listed in the instructions. So far, I’ve got about 10 hours of cooking logged on them and they’re still going strong. Just have to be cautious never to turn on the machine unless the coils are submerged. I’m actively investigating finding an upgrade to the coil solution, though.

    @Alvin Awesome! Please send pics when you’re all done. I’d love to post a gallery of the DIY adventurers who took on this challenge themselves!

  18. Pete W

    To streamline things and because I figure it is the component most likely to give out, I may just leave the pump as a stand alone component. I will still mount it exactly like you did but just plug it into the wall separately. Is there any reason that should cause me any issues?

  19. @Alvin Congratulations! It looks awesome.

    @Pete W Nope, no reason to worry about the pump. I’d actually imagine that these little pumps are pretty reliable. Since they’re fountain pumps, they’re designed to be left on continuously. My coworker had a mini fountain in his office that he left running for months on end. But, there’s no harm in wiring it separately, just in case.

  20. W.

    Trying to get my buildout finialized, but I’m not sure if I’ve got everything correct. I’m not electronically inclined at all, so I’m not able to pinpoint where I may be going wrong.

    If anyone could take a look at the manual for me and let me know if it has an internal relay, or do I need to use a relay like Scott has? link:

    I may have some other questions, but I think I’ll start with that one.

  21. @W It’s best to use a relay, since usually the relays built into these controllers are only rated for switching about 375W, and your heaters add to 900W.

    If anyone has had success using the relay built into the controller, please let me know, as it would be great to save a solder connection!

  22. Pete W


    Any other ideas on where to source the PT100 probe? The company that sells them on ebay is backordered and has no idea when they will get more (though this has not stopped them from listing them on eBay).

  23. Jon Trickey

    I got my PT100 probe, which ended up being the hardest part, and the controller works much better now. Looking back, I don’t think I had the other probe wired correctly now and that was causing my temperature fluctuations. You need the PT100 probe if you want the display to show 1/10 of a degree. I’m guessing that the k-type thermocouple cannot measure that precisely. I also figured out how to get it to display in Fahrenheit, but that ‘broke’ when I changed temperature probes. I’m guessing there is a bug when it tries to convert decimal places.
    My little crock pot setup has been working great so now I am trying to decide whether to go with the immersion heaters or a large (18+ quart) counter top roaster oven. I like the flexibility of the immersion heaters, but I also like the simplicity of a self contained unit.
    @Scott You have me a little scared about the built-in relay now. Mine has been working fine controlling a small crock pot but I might augment it with a larger one before I add more power.
    @ Pete W I searched for a while before I found a source for the probe that wasn’t outrageously expensive. I got this probe but I have a local Grainger store. This place has it too with free shipping:
    The probe only has 2 wires so connect it to terminals 10 and 11 and jumper 11 and 12.

  24. hi scott

    i’m thrilled to see this. can you built one for me. i’m a full time cook and have no time and knowledge about electricity. i thought of buying a professional but the restaurant can’t afford it. it’s a wondermachine. what this thing does to proteins is beyond we’ve known about cooking. i had a machine for two days and putted in everything i had, fish, tender and fat meat and everything comes out like something else. exciting. poaching was yesterday.
    let me know your conditions.


  25. alvin schultz

    any one who has built one of these NEEDS to try eggs…just sous Vide in the shell (no vac sealing needed )@ 64.4C. incredible.

    I just finished a 25hr short rib and my internal relay worked out great…

    Thanks again to scott for the instructions and build!

  26. JT


    Just a small question for clarity. The acylic container list in your reference are 4.75″ x 4.75″ x 5.25″. However the template is 4″ x 6″. What size container did you use? I just want to order all the right pieces.


  27. Scott – My heating elements are touching each other – can they touch or will this short the device?

    The silicone caulk isn’t firm enough to keep them from touching. I tried liquid weld but that isn’t work either.


  28. @jimmy The heating elements can touch each other – that is OK. Inside the coils, there is a resistive wire that gets hot. The wire is surrounded by a non-conductive material, like a ceramic powder. This prevents any electricity from travelling to the outer part of the coil. Otherwise, you’d be electrocuted if you stuck your hand in the tub of water!

    So, it is fine if your heating coils touch. They won’t short out.

  29. Anders

    Hi Scott
    First of all this is the coolest homemade gadget i have ever seen.
    Lately I have been reading alot about sous vide.. And i have decided that I simply have to try building an immersion circulator like yours. The problem is that I live in europe (denmark) where we have 230 v – so my question is do you think I can use your rick?

    The PID should not be a problem, but what about the immersion heaters


  30. @Anders Yes, this design will still work for 230V. However, you’ll need to find immersion heaters that are rated for 230V, or are rated from 110-240V. I’ve seen a few on eBay, but you might try hardware or camping stores, or an online retailer in your area. Also, (IMPORTANT) the power output of the heater will be doubled at 230V compared to 110V. So, you may want to alter the design to only use 2 heaters instead of 3.

    Best of luck!

  31. @JT I’ve finished my testing with the heating element you linked to. I got a conclusive NO 🙂 Although the element works fine, electrically speaking, the top of the element gets far too hot for the plastic housing. After less than 10 minutes of heating, mine literally melted a hole through the enclosure and fell into the water bath. Good thing this was an intentional test!

  32. JT

    I understand the science, Acrylic does not resist heat very well. Have you uncovers any other options for the heating element or should I stay with the NORPOR559. Thanks for the help.


  33. Ravi

    Have you seen as an alternative for the heating elements? I can’t quite figure out the dimensions of it, but the safety shut off is nice. To build in a safety for your version I was looking to use something like

    Most of the parts have been ordered so I’ll update with my final product. I think I’m leaning toward a modular version that @alvin did.

  34. Pete W

    Just finished my build and waiting for some stuff to dry. Thanks for the plans, Scott!

    One thing I noticed during the build: I followed your instructions exactly at first but I kept screwing up the heater silicone as I was trying to move things in and out of the casing. I eventually just left them dry fitted and siliconed at the end. I think it is much easier that way.

  35. Pete W

    Well I just plugged it in and it’s not working. The PID comes on, the temperature reading is correct, I’ve set eveything but even when the light says that the heaters should be on, they are not. I’ve measured across the relay and there is a current going across it. I even undid one of the heaters to make sure they were good. It worked fine when not hooked into the machine. I’ve tested every significant point of connectivity.

    I am at a loss. Anybody care to help me troubleshoot this?

  36. @Pete W
    When the output light comes on, can you hear your relay click? My guess is that you have the relay wired wrong – since relays don’t generally have their pins or posts labeled, they can be tricky to wire correctly.

    Test that you’re getting a DC voltage (somewhere between 5V and 12V) coming off your OUT pins (5 & 6 on my controller). If you’ve got voltage, and you’re confident that you’ve got the DC voltage wired to the correct posts on the relay, but you’re not hearing a clicking sound, your PID controller might not be putting out _enough_ voltage to trip your relay. Try connecting a 9V battery to the same pins on the relay. If it clicks, that’ll confirm it. To remedy, check Radio Shack or another source for a relay that has a lower voltage, like 5V.

  37. Pete W

    Success! Thanks for your help. I did have the relay wired wrong. I was thinking the schematic of the relay was oriented as if you were looking at the bottom side (where the posts are).

  38. Kevin

    Cool idea, but be careful. As a couple of people have said, you have a lot of power hovering over a bath of water.

    Others have suggested a GFI plug, but I am not sure that would get you anything since there is no ground in this setup.

    The best way to make this setup safe would be to use a metal box instead of clear acrylic. The ground from the wall outlet should then be wired to the metal box. Then you could use a GFI plug and even if a short occurred it should be contained within the box.

  39. I think I’m close, but mine is having problems. The pump turns on, but the device is not heating.

    OUT1 stays on all the time, the PV and SV values still don’t make sense, even after trying to program using the PDF. I’m not 100% sure I programmed it right so I will keep checking that.

    When I play around with the set value, I’ve heard the relay click and OUT2 turns on.

    I realize people are asking tons of questions, and it must get old, but any thoughts are appreciated.


  40. @jimmy Here are some debugging steps to take:
    1. By default, the controller is (probably) set to Celsius. Room temperature will be somewhere around 20-25C. Hot water from the tap will be around 45. If you’re seeing wierd values from PV, you probably need to adjust the order in which your thermocouple is connected to the PID controller. The pin numbers will vary by make and model.
    2. OUT1 should switch on and off when your SV and your PV are close to each other. If you set your SV a few degrees above PV, OUT1 will go off. If you set your SV a few degrees below PV, OUT1 will go on. If you’re seeing opposite results, look for a configuration setting in your controller’s manual for heating/cooling. Set it to heating.
    3. If the OUT1 light is behaving correctly but your heaters aren’t turning on, make sure your relay is wired correctly. The relay should click whenever OUT1 turns on, and click again whenever OUT1 turns off.
    4. With a multimeter, check the AC voltage on the leads going to your heaters when OUT1 is on. It should read around 120V. If not, your relay is wired wrong.
    5. If you get a positive result with #5, you’ve burned out your heating coils somewhere along the way. It’s very easy to do – it takes less than a second of ON time out of water. Unfortunately, you’ll have to get new coils and try again 🙁

  41. Scott – Thanks for the feedback. I did a little more testing on the device.

    Out 1 is turning on because PV PV. Any idea what this means? Does it matter?

    I’ll check with the multimeter next. Hopefully I didn’t burn out the coils, I’ve only turned on the device 3 times, and each time they were definitely in water.

    Thanks again!

  42. Pete W


    Make sure you test the output from the PID as well. Despite my earlier exclamation of success (My heaters came on for the first time and I thought I had it, I didn’t). It turns out my PID was only putting out about 6.5V and it was not enough to power the magnet in the relay. I had to change over to a SSR (the Radioshack relay is actually mechanical). Now it works fine.

  43. Pete W


    One last question: if I’m getting lots of variance at different locations in my water bath as it’s warming, should I just cut up the speed of the pump or will the system just stabilize once temp is reached?

  44. @Pete W
    Yes, it’s normal for the temperature to fluctuate by location while the bath is still heating. But, once it has reached temperature (and held it for a minute or two) you shouldn’t see variances greater than -1C. Now, some variance will be inevitable: if you put a frozen steak in a warm bath, the water right around the steak will be colder. But these differences will even themselves out during the cooking time.

    If you are observing major temperature variances once the bath has come up to temp, consider the shape of the bath and the placement of your machine to optimize water flow. Also, it’s not a bad idea to keep the flow of the pump set to maximum.

  45. Could somebody clarify if the temperature controller stores away things like the PID coefficients and other settings to non-volatile memory so they don’t need to be re-entered after power-up every time? Thanks in advance.

  46. Pete W – I had the same problem as you – I was looking at the relay as if the pins were facing me.

    I changed the wires and now my heaters turn on, but now I have a new problem…My heaters won’t turn off, lol. Even though OUT1 turns off on the PID, the heaters continue to heat the water.

    Any ideas?

  47. Alvin Schultz

    I think i blew out my internal relay… multi-meter has NO contenuity over 4/5/6 at all!
    May need to swap my controller with a 12v relay out…
    going to confirm with some more testing…

    FYI- had at least 60 hrs on my system.

  48. Alvin Schultz

    yes my PID has an internal relay. it is what clicks when out1 comes on/off…i can still hear it clicking, but I have no continuity across any of it’s terminals (no or nc)
    going to try and find a replacement relay first if that’s no go, then off to a new PID…I have become to acustom to Sous Vide to give it up!

  49. Pete W


    That’s the exact progression of my problems (No Heaters, Heaters on all the time). Your PID is probably not sending a strong enough signal to flip the relay. You need to get a solid state relay. They can run on much weaker signals (mine can be tripped with only 3V).

    Auber has a 25A that works well (it is considerably more expensive at $15).

  50. Pete W

    Also, the Auber relay is nearly impossible to miswire because it is well marked and it only has normally open posts (as opposed to the Radioshack which has both normally open and normally closed).

  51. Pete – I may check that out, though I’m going to continue to mess with this in the meantime. A friend of mine is using the exact same PID and his is working. However, we can’t figure out what’s different in our setups. I have checked for continuity and everything seems to be good.

    Right now I believe am connected to the normally closed post. If I am looking at the relay, with the pins facing up towards me, the bottom three pins are all connected, and only the top right pin is connected. I am thinking I should be connected to normally open instead?


  52. Pete W

    You should definitely be connected to the normally open which is the top left if you are looking at the pins.

    It’s pretty easy to check your signal from the PID with a multimeter. Just make sure you disconnect the heaters first (or have them in water). Then just turn the PID on and check to see how much voltage you are getting off the SSR posts. If it’s less than about 7V, the relay won’t work. Mine would click a lot when the system first started up but I finally figured out that it was moving the contact but not enough to complete the circuit.

  53. David

    Mounting this whole thing hanging over the water bath seems just plain silly to me. Put the controller & relays in a water-resistant enclosure that sits on your counter. Mount one or more outlets on it for your heating element(s), and use a temp probe that has a couple of feet of cord on it. Make a small aluminum u-bracket mount to hold the heating element(s) in position over/in the water. As for GFCI, you don’t need a GFCI outlet in your controller box as some have suggested. If you are using this in the kitchen, you will already have GFCI protection on the circuits, assuming your house was built to code. You really can’t chain GFCIs together. Most won’t work at all of they are daisy-chained. Separating the control unit from the heating until gives you infinitely more flexibility.

  54. David

    On a separate note, what about using an insulated cooler rather than a plastic storage tub for the water bath? Would that make it easier to maintain temp, due to less heat loss to the surrounding environment?

  55. Hi David,

    The separate controller solution seems to work well for a lot of people, and certainly has some advantages from a practical point of view. For example, as other folks have noted in the comments, you can use a crockpot as your heating source. That’s a good point about the GFI outlets, too.

    I tend to prefer this design because it keeps the heating elements, temperature probe and pump nicely secured in the water bath without me having to rig something up to hold them in place. As you may know, this design is similar to how professional heating immersion circulators are built.

    To your question about using an insulated cooler, it may help, but I don’t think it’s necessary. Even in a metal hotel pan, which has a large surface area and is anything but insulated, the controller is able to hold the temperature extremely stable with a very low duty cycle (the heaters are turned on briefly and infrequently). To conserve a little power, sometimes I put my hotel pan on a cooling rack so my granite counters don’t act as a heatsink. If you wanted to make the water bath much larger, perhaps 5 gallons or more, then the insulation might become more of an issue.

    Hope this helps.

  56. PedroG

    Scott, you have done a professional job, I am amazed!

    How many hours did that take you to build? What would be the price of your SV-rig if you charged 50$/h?

    I wonder how long the relay will work as it has to switch on and off every few seconds. SousVideMagic or Auber PID-controllers use Semiconductor Controlled Rectifiers (SCR) instead of a mechanical relay. If your relay should wear, you might get a SSR e.g. at 15$.

    Indoor fountain pumps in my experience will withstand 60°C
    although specifified for max. 35°C. From the experiences of a friend of mine I know they will not withstand 80-90°C. For temperatures above 60°C you may use an aquarium bubbler.

    If your container is not well insulated, PID-control is easier than with e.g. a well-insulated rice-cooker, as heat loss counteracts overshoot after initial ramping up or after a disturbance load.


  57. Elijah

    Does the CD101 PID have an internal relay? I just ordered one and am worried that Alvin’s result (blown internal relay) will will happen to me after ~60 hours. If I hook up the Auber relay is there a way to bypass the internal relay, if indeed it does exist?

  58. MikeJ

    Scott, very nice work. You should be proud of all the geeky foodie DIY-ness you have inspired. I just finished building and troubleshooting one for myself using a mix between your design and Alvin’s modifications.
    I’ve built similar temp control circuits in my grad school research, but I hadn’t thought of applying such knowledge to my hobbies. Now you have me brainstorming how to make a DIY chamber vacuum bag sealer. The FoodSaver systems wear down so fast, while professional sealers are so expensive. It seems like one could put a cheap impulse bag sealer inside a high-density plastic bell jar evacuated by a surplus scientific vacuum pump and you’d have it. The problem I hit with the idea though is you’d need some sort of vacuum feed-through to press down the sealer bar inside the chamber. If anyone tries this idea remember: Safety First!
    My first 64.5C eggs are cooking now.

  59. Win a Sous Vide rig !

    For lack of contestants, FreshMealsSolutions have postponed the deadline of their “Most Innnovative SousVideMagic Sous Vide Cooker Contest”, so you still have the chance to win a SousVideMagic 1500D plus FreshMealsMagic.

  60. Anonymous

    I built the thing.
    The temp controller is near impossible to program. Find a smart buddy and pay him royally. Once you get it right it works amazing. Within .1 deg C for approx 4 gallons of water.
    Use an igloo cooler to keep the heat in longer. Also, I put the pump on the opposite end of the cooler to help move the water.
    Bed Bath and Beyond has the immersion heaters for $8 each in store.
    Nice design.

  61. Elijah

    Since the aquarium pump may not be able to handle hot water (180 for duck) for long periods of time, it may be best to create a “reserve” supply of cool water to place the pump in, and use the plastic tubing for the pump that comes with it to feed into the hot water.

    A better solution might be to use a regular air pump in the dry unit with the PID, and just feed a steel tube into the hot water. Any suggestions on a non-submersible pump that would work?

  62. Elijah

    Sorry to post again. If there’s a forum or email you’d rather I use please let me know. Why do you suggest the pt100 over k type thermocouple? Is it because K type has a 2.2 Celsius accuracy buffer whereas the pt100 has 0.3? Or is it something more horrific like “k type is made of lead”? 🙂

  63. @Elijah – This is a fine place to ask questions. This way, everyone else can see the answers posted here.

    Regarding the aquarium pump, I’ve tested two different models and both performed well during sustained high-heat cooking. So far, I haven’t had a single pump break down.

    Non-sumbersible pumps are a little harder to find and are more expensive due to the type of construction they require. But, one alternative I’m looking into is putting a motor in the housing to drive an impeller in the water. This would definitely be temperature safe.

    With regard to the thermocouple, I recommend the pt100 purely for accuracy. I don’t know of any food safety issues associated with using a different type of probe, but with most PID controllers you must use a pt100 if you want to control temperature with an accuracy of .1C or more.

  64. mpj

    Regarding pump breakdowns.

    My first pump broke. It was an ‘indoor water fountain pump’ from eBay ( It was working fine around 65C/150F but broke at 83C/180F. At that higher temperature the epoxy resin within which the pump is enclosed swelled to the point where the propeller shaft jammed solid.

    I have since ordered a marine aquarium ‘powerhead’ (, as recommended by some DIYer. I’m not sure if it will be any better, as AFAIK all submersible pumps share the resin-enclosed design.

    Perhaps the safest thing is to use the pump only for meat and eggs where the temperatures are lower and more exact. Next time I try to cook apples, I’ll leave the pump out and allow a small temperature gradient.

    My in-progress implementation of the PID controller is here:

  65. Elijah

    Hello again. I got my PID on eBay ( and it says it’s good with a SSR. I bought the Auber SSR mentioned in an earlier post, but it doesn’t seem to trigger. The internal relay works fine, but I’d like to use the SSR to limit the amount of wear on the internal relay. The ebay listing says the PID supports Voltage Pulse Output, but I can’t seem to find any setting to use this!

    Also, does anyone have a complete listing of the CD101 setting code explanations? For example “SL 2” is the setting for Centigrade or Fahrenheit (0000 for celsius, 0001 for fahrenheit). I can’t seem to find info on the others though (SL 3,8,9,10,11).

  66. Elijah

    Since the SSR setup isn’t working, I reluctantly rigged this with the internal relay (posts 4/5) to a GFCI outlet. Last night I tried with a pre-seasoned (teriyaki) and already vacuum 1lb sealed beef shoulder from Publix grocery. I left it in for about 2 hours at 135F. AMAZING texture and flavor after I pan seared the cuts for about 10 seconds on each side. I did eggs at 148F (64.5C) for an hour, but they were kind of slimy. I think I’d increase the temp a few degrees or the time by 15-20 minutes. I also picked up a FreshSaver ( from Walmart for about $16. I’m trying my own garlic pepper & Worcestershire seasoned steak right now!

  67. jimmy

    Elijah/Anyone else –

    So using the SSR didn’t work? That was going to be my next step. I’ve been stuck for the last 3 weeks, I just can’t figure out how to finish this thing. I never hear any clicking in my external relay, just the internal relay.

    This is all way new to me, so I don’t really understand why there is both an internal and external relay. Why is an additional relay needed?

    Can you explain how you set your unit up without the SSR?

    I believe Pete W used this SSR and it worked ( any idea why yours does not?

    At this point I’ll pay for help! 🙂



  68. Pete W


    If you are hearing your internal relay click then your PID settings are wrong. The internal relay should be inactive when you have the PID set up to run an SSR. Check your manual and change the mode to external relay.

  69. Elijah


    I don’t think that’s possible with what I have. On this particular ‘build’ of the CD101, it is set to Relay only, the guide doesn’t mention changing over to SSR, and the company I bought it from admitted they sent the wrong one. In case this happens again, do you know which setting controls SSR and the internal relay?

  70. Karen

    I love this!!! I have already started my sous vide project using our plan. I am a student chef and I have been looking for a cost effective way to cook using sous vide. I attended a wonderful chefs’ seminar where we discussed the requirements for sous vide. It is important to remember the vacuum bag part of the equation. The ‘Food-Saver’ is universally accepted as sous vide worthy. Zipper bags are NOT. The worst case scenario is the introduction of bad critters into the slow and low cooking method causing the eater to suffer nasty illness.

  71. Pete W


    I am using a different PID than you are so I can’t help you with the setting. Mine has an output setting that you have to change to disable the internal relay and enable the SSR controlling signal.

  72. Erik

    Hey Scott, thanks for doing the writeup!!! I was just looking at the specs for the PID and it says that it is a 24V output, if this is correct how is this working with 120v heaters?

    thanks in advance


  73. Rodney Sparks

    Have you run a test yet to see what the maximum attainable bath temperature is with these three heaters? At some point, is insulation needed, or can make the water boil?

    Awesome setup. I’m going to build one at some point for sure. I’ll likely mount the heaters and temp sensor in a plate that is separate from the controller housing. I’m thinking I might then cut the lid in thirds or so, and then permanently attach the heater/sensor plate to that 1/3 chunk of the lid (leaving a notch in the edge of the lid for the pump power cord). I’d then put the controller in an external enclosure that has a 4-position AC outlet on it (can one be independently wired, or are they all wired in parallel?) and tall rubber feet to get it up off the countertop. I personally don’t like the idea of precariously perching 110V electrical components over water, only being secured by a layer of glue… 😉

  74. mark n

    Hi Scott,

    Just make the cooker.
    The element stays on for some strange reason. The displays flashes when the temperature goes over the set point. I have adjusted the pid for the pt100 but can’t find where to change the decimal setting.

    Can you help?

  75. Ricardo de Freitas

    Hi Scott, first I want to congradulate you on this DIY and how of a great success and fun project it was to follow and built myself. I made a replica of what you have made to kinda feel how it works. I have a basic prototype, nothing is set in stone if I’ll keep your setup to have everything included as one system, or use Alvin’s idea on it.
    I have 2 questions regarding my setup. Thermometer and Relay clicking noise.
    I have my system set to 60, both green and orange are at 60, continuously every 1-2 seconds intervals the relay keeps clicking on and of. Is this perhaps on the degree of accuracy that I have set it up or is it normal? Also my PID says the temp is at 60, but when I use my digital thermometer, it shows that I’m at 63, so I have a 3 degree variance that isn’t being read properly. Do you have any idea for a solution, or my pt100 might be dead?
    Thx in advance!

  76. Phillip Kramer

    @Alvin I have the JLD612 PID as well, and I have not yet figured out how to enable .1 degree accuracy either, but I found a “manual” for it at
    It isn’t very well written, but it does have some useful info, and you might be able to glean enough to figure out the accuracy setting, I couldn’t seem to find it.

    I went with the receptacle build that is similar to yours Alvin, but my problem is with the SSR, I don’t know if the SSR is faulty or what, but after wiring it in, I am finding that there is always voltage applied to the receptacle. Using the multimeter I am finding continuity between contacts 1 and 3 which does not make sense since 1 is supposed to be the load side of the relay and 3 is supposed to be the control side of the relay, shouldn’t these be isolated from each other?

  77. Pete W

    Phillip & Ricardo,

    You’ll need to go through the settings. INTY will be the one where you can choose the probe you have. There are two different settings for the PT100 in the PID. One is listed as PT100 and one as PT10.0. One of those will be the settting with the extra decimal place (I believe it is PT10.0 but I am not home to check right now).

    There is also a setting that will apply a variance adjustment if your temperature is incorrect. However, I wouldn’t automatically assume that the PT100 is the one that is incorrect unless you are using a high accuracy thermometer to calibrate against. Most kitchen thermometers are not very accurate. If you don’t have access to a laboratory level thermometer, the cheapest substitute is a basal thermometer which you can get at most any drug store for about $10.

  78. mark n

    I also noticed that as the temperature reached the set point the out 1 light flashed a couple of times but there was no clicking sound. Is it the relay that is not working properly or the PID controller?
    I can hear the relay click on once when I turn on the unit at the beginning and also when I turn off the unit. The alarm light comes on once it has gone a couple of degrees over the set point and then the temperature reading starts to flash.

  79. Ricardo de Freitas

    Hi Pete,

    Thanks for the tips. Where can I see those settings? The way I set it up was with the provided pdf file that Scott provided. There I think it was SL1 you can set the codes for the thermometer. I used 1100 for the PT100. I did check my kitchen thermometer that I use. I boiled water and stuck it in and it stayed at 100.7 C which is pretty close to perfect I guess. I will take a look as soon as I get home and see if I can find the variance configuration and see if I can play around with that. Also if possible Pete, can you provide me with the settings you used in Cod0000, 0001 and 0002? Thank you in advance.

    Also for everyone else. I found a great discussion about sous vide or cooking with low temps. is the link. Its very informative and will start giving you some basic principles and ideas on cooking in the water bath.

  80. Rodney Sparks

    I just looked at Alvin Schultz’s blog:
    and that’s EXACTLY how I want to build mine, with two exceptions:

    1) I’m going to use a 2-piece sheetmetal enclosure for the electrics, with safety ground connected to it.
    2) I’ll likely just put the heaters and sensor probe in an acrylic or ABS plate that sits across the top of a storage bin and has #10 screws hanging down that engage with mating holes in the rim of the storage bin to make it stay put. If I end up wanting a more generic solution like he built, I’ll do what he did… For now, I just want a nice, stable setup on a specific storage bin that can’t tip over, etc.

    Good stuff! Can’t wait! Just bought most of the parts!!! 😉

  81. Pete W


    There is a really in depth discussion on eGullet. It’s over 3500 replies so there is a lot of information there.


    Sorry, I misread who posted above and thought you had the same PID as Phillip (I see now it’s Phillip and Alvin that have the same). The manual he posted looks a lot like mine and so I knew how to fix the issue on his. Looking at the manual Scott posted, I am not sure how to fix your decimal place issue. Perhaps Scott will chime back in.

    As for the thermometer issue, keep in mind that water’s boiling point can change depending on altitude and whatever minerals or additives are in the water. Your calibration method is probably good enough if you are not going to play with the edges of safety (for instance around 132F for over 4 hours). If you are going to do long term cooking at the low range of temperatures, I would invest in a basal thermometer.

  82. alvin schultz

    Just wanted to thank Scott again for doing the leg work on this first DIY….truly revolutionary stuff we’re doing here. I had a commenter on my blog from Australia wanting to bring Sous Vide to his restaurant.

  83. Ricardo de Freitas

    So i’ve contacted RKC for original manuals for the CD101. Anyone cares if I email them and they can upload it for future references?
    Pete, I fixed my issue with the temperature. Just ad my variance in it and now it perfect.
    I’m pretty close to sea level so the digital thermometer works great, but I took your advice on the basal thermometer and its same as my digital one.
    Happy cooking 😀

  84. jc

    I’d like to offer one comment on an other excellent design. That rocker switch is rated 6 amps at 125VAC. Those three Norpro 559 heaters are 300W each, for a total of 900W, plus 2.7W of the pump and whatever power the pump and PID controller pulls (unspecified, but lets say 7.3W for fun).

    Assuming 125VAC, that’d be 7.28 amps. At 110VAC (more likely), that’s 8.2 amps. I think I’d consider looking for a heavier duty switch. Turning on the unit isn’t much of an issue, because you’re not switching the full current (the PID controller is keeping the heaters off). The switch is less likely to fail while it’s running. However, when turning it off, if the heaters are powered, you do risk arcing. You may want to consider turning off the heaters via the PID controller first, the powering it down.

    Nonetheless, I would strongly recommend upgrading to a less sexy higher current rated switch 🙂

  85. bonafidebob

    Your design is just what I needed to get off my butt and build this. Thanks for the great writeup, and for all the helpful comments. I’m going to go with the standard 120V outlet on the controller, so I can use it with any immersion heater, or crock pot. Hopefully this will also make it easier to move between coolers or other containers.

    With a sufficiently large and insulated water container (20 or 50 gal cooler) would the pump even be necessary? I’m kind of thinking that once the water was up to temperature, a single immersion heater should be enough to keep the temperature constant.

  86. @JC Great comment! Yes, if you’re building one of these, you may want to invest in a heavier-duty switch rated for 10 Amps or more. Since this was a DIY project done on the cheap, it’s not without shortcuts, hence the big safety warning. Using a lower-rated switch, at the worst, you may trip your kitchen’s GFI outlet or circuit breaker. But if you can find one that fits your budget, I agree with JC: get a bigger switch.

    @Bonafidebob Yes, you can certainly get by without a pump for circulation – in fact, the Sous Vide Supreme doesn’t have a circulator and relies only on convention currents for circulation. But, you will end up with pockets of hot and cold areas that will vary as much as 2 degrees C, depending on the shape of your contianer. If you’re cooking for many hours, the temperature will even out over time. But, if you’re cooking eggs, which only take an hour and are very heat-sensitive, you may want to spring for some type of circulation mechanism for best results.

  87. jc

    My spelling/typing in the previous post was an atrocity…

    Regarding the switch: If it fails, it won’t necessarily trip a breaker. It may just burn up. It’s unlikely to get hot enough to ignite the plexiglass/acrylic, but because it’s in series with the load, it probably won’t trip the breaker.

    I’ve found a source for heat tolerant pumps on eBay @ They’re good to +80C (or they’re claimed to be) or 179F. They stand a better chance of surviving the higher temperatures than the aquarium pumps. The draw back is that you will need a 12VDC power supply for them. eBay to the rescue again: (Sorry about using absolute auction numbers, I know they’ll go away eventually. However, a generic search turns up too many wrong results).

    My current plan for a sous-vide cooker is using a half-size steam pan, 2 2000W water heating elements in series, the PID controller and PT100 probe, and the above pump. I’m going slow, since I’m doing it on the cheap. The web page is located at Email is jcwren if you have questions or suggestions.

  88. @JC Sounds like a plan! FYI, I’ve played with those Camco water heating elements and they are very powerful. The NPT threaded base of those elements gets nearly as hot as the coil itself, so make sure that it is mounted in a metal enclosure using a metal nut.

  89. Yish

    @JC I used full size 6inch hotel pan i got in chinatown for $18 and a single 1500 watt 120V water heater element (from grainger) mounted in a hole i drilled on the side of the hotel pan. This setup is working great for me and I was worried the 1500 watts might be too much but turned out to be perfect from what I can tell. My accuracy never fluctuates beyond +/- 1 degree and usually stays within 0.4 degrees.

  90. Alvin Schultz

    for those using SSR. I ordered this SSR from virtual village:

    they sent this relay:

    a meter on the SSR output measures about 18v when out 1 goes on, which means it isn’t out puting enough to trigger the relay, right? the second link shows on>45v

    So for now, I’ll connect to the J2 output and set OutY to 1 on the TET/JLD 612 PID.

  91. jc

    @Alvin, the relay they sent you requires an AC input in the 80 to 250 volt range. It’s basically an AC operated relay for the purpose of switching heavier loads on the high side (don’t know about your electronics knowledge, so if this is dumbed down too far, sorry about that). You might think of this as a relay where you want to switch a large load (like the heaters) with a small switch that can handle only less than 1 amp. You definitely want the SSR-40DA. Unfortunately, Googling around for these models reveals a bunch of conflicting images and data. These are made in China, and subject to translation problems. There are some on eBay that are about the same price with shipping, and generally the pictures more often reflect what you’ll likely get (eBay is my first stop for shopping for a great many things!) Search for “40a ssr” and check the control voltage for being 3-32VDC.

  92. Erik

    just placed my order for the PID and the thermocouple on ebay, I can’t wait to get the parts so I can get started!!!

    BTW I have an idea for using one of the 1500W screw in water heating elements, I will post pictures of my progress.

  93. sam

    I ordered a PID from ebay earlier, and I think I have goofed as its got the internal relay rather than voltage output. The issue with the relay is that the current support is low (3A), so it probably needs an external relay anyway.

    My electronics is rusty, but couldn’t I use a 120v ac relay instead of the low voltage one you used, and then just use the internal relay to toggle mains power to a higher current relay, say something like:
    which should be able to handle a 1.5kw heating element?

  94. @sam Yep, that relay will work instead of a low voltage relay. I’ve tested one with another contorller I’m using. The only “drawback” is that these relays make a pretty loud click, and if I turn the lights off, I can see a blue spark every time it clicks on and off. That said, I’ve got 150+ hrs logged on that relay already and it seems to work like a charm.

    I’ve ordered a batch of SSRs (solid state relays) which should be the most durable and long lasting. They’re expensive, but if you order them in quantity, the price isn’t too bad. I can’t wait to see how they perform.

  95. sam

    Are you using PIDs with the relay output or a low voltage signal?

    So, it looks like might be an SSR that will switch 10A load from a 120AC signal. If there was a lower voltage output from the PID, I’d prefer to use that for signalling, but I don’t know if that will be available on the one I’ve bought.

    Where do you get components – I’m originally from the UK, and it seems allied is the US version of RS (not radio shack) which would be a natural choice there.

  96. @Sam The PID controllers I’m using have both a low-voltage output and a 120AC output. The SSRs I ordered are designed for use with a low-voltage input. I sourced them from eBay from some company that ships from Hong Kong. Still waiting for them to show up…

  97. Jusitn

    I built this, pretty much exactly following scotts plans, and so far (i’ve only tried it for about an hour so far) it works GREAT (thanks to whoever commented suggesting using AT, i was so confused till i tried that)
    i happened to stick a stem thermometer into the water just to see how the temperatures readings compared (my change was to use an enclosure from radioshack, i was worried i have the pt100 too close to the heaters. when i did so i happened to be resting my other hand on the faucet and felt a zap…so i started testing everything, and the current isnt coming from inside the enclosure, im 100% sure of that…so its down to the heaters (or possibly the thermocouple somehow??) also…the current is only present when the heaters are off…
    anyone else experience anything like this?

  98. I just built this one after googling around and stumbling upon your article.

    I already had a PID controller from auber instruments, thermocouple and other stuff so I could try this out for extremely cheap. I’ll be doing my first sous vide steak tonight, should be interesting 🙂

    PID controller and thermocouple from auber instruments
    2000w element from a water heater
    20A solid state relay and heatsink (big black thing on left of the controller)
    10l box as a reservoir and a small box to keep the components
    600l/h eheim aquarium pump for circulation. Turned it down to lowest setting for this tho.

    Did a few trial runs and seems like all components can handle this beautifully. I’m pretty proud of it given that I put it together the same day I read your article. Takes about 5 minutes to get cold water to 60 degress celsius and everything can be unplugged and put in the box for storage.

  99. jc

    @Gleraugu, do you have any more details on the heating element you used (manufacturer, part number, price, etc)? I’ve been going through Google looking for circular heating elements with little success.

  100. @jc: I’m in Iceland so prices are probably not relevant, but I got the element from an electric kettle. Most cheap kettles have elements that look exactly like the one I used, and come with a handy silicone gasket you can reuse. I paid about $20 for my kettle, but I’m sure you can get it for much less in USA.
    Another handy thing about these elements is that you can connect them with the same cable as goes in the power supply of computers. Connector is called YC-12 according to a quick google query. I used an old power supply cable, cut it in two and connected inside my wire box.

    Beware that some kettles have elements embedded in the bottom and are hard or impossible to scavenge. You want the cheap looking plastic kettles 🙂

  101. BobW

    Came here via a link from Followed the clear storage container link to The immersion heater and the PID Temperature Controller are listed as frequently purchased together.

  102. duncan

    I like this design, but I wonder why you didn’t use a water-heater element. They’re designed to heat larger amounts of water and are cheaper than the heater elements you selected. I’ve seen ’em as low as $10.

    Just my $.02

  103. Duncan,

    A water heater element (or something very much like it) was tried by Scott, and it melted the case. It would require a special screw-in mount, and I think just for the sake of not re-designing the entire thing the others were used. But you are right, they are more powerful and economical.

  104. Matt S

    I’m not 100% sure, but this seems to have the same settings as the CD101 -> so you should be able to set it up for a PT100 RTD type sensor. It seems that Jon Trickey got it working (he didn’t mention going through the menu though!).

    Anyone got any more info on the CD101?

  105. sam

    So I’ve been playing with a crock pot waiting for the other parts to arrive. It seems to operate in the right temperature ranges, but is very slow to get there. I think the heater is in the 300W range.
    The power of the heater will affect how fast it heats up, but once at temperature, how much does that affect the ability to control the bath – how often is the controller cycling the heat on/off?

  106. Pete W


    Crockpots are very well insulated so they don’t take a whole lot to hold at a temp (very few cycles)though it will have a longer recovery time (right after cold meat is introduced) than other SV rigs because of the weak heater. It’s also important to tune the PID before you start to use it.

    Convection is the biggest problem with crock pots as they are usually heated around the sides. Adding the pump should solve that problem though.

  107. LanceW

    I have the CD101 and using several of the posted manuals, I was able to set it to Fahrenheit with a 1 place decimal. I also was able to change it from a K thermocouple to PT100. I ordered a PT100, but my thermocouple is labeled PT100+, don’t know if that matters.

    My problem is that it is reading 30 degrees low. I have a glass of water at 100, and the unit reports 70. When the glass is at 72, it reads 44.

    Does anyone have any ideas on how to fix this?

  108. Jan Willem


    You can compensate the reading if that is really the problem.
    Press SET for a few seconds until you reach the menu items.
    Keep pressing set a few times until its reading Pb, here you can compensate the sensor
    Pb means PV bias and the description says sensor correction

    Jan Willem

  109. sam

    I was trying an apple recipe that involved 85C water, and it was taking forever with the crock pot, so I switched to a pan on the stove, using the PID as a temperature guage. The mistake was to also use the aquarium pump – the water got too hot and the plastic warped. — conclusion – aquarium pumps are not made for that kind of temperature.

    I’ve ordered the barrel heater listed earlier and am going to try the in a plastic tub method, but need something for the circulation. What do the commercial units use?

    One pump idea is something like which is for radiant heating and is good for 110C water which should work? but that blows past the $75 budget concept.

  110. Erik

    hey all, I just got done building my unit and, of course, its not working properly. when I plug the unit it and turn it on, the heater just starts going, like the relay is doing nothing, I tried switching the wires on the relay but that didn’t change it. Also my PID is clicking on and off (out 1) about every 10-15 seconds.

    some help would be greatly appreciated, if someone has a pic of how they wired theirs for a SSR that would be great


  111. Congrats!
    You may not want to use our SousVideMagic controller, but you should look into our FreshMealsMagic (submersible heater with integrated air diffuser).
    With FMM
    1. Your controller does not have to be mounted on top of the bath.
    2. The heater is completely submersed at the bottom of the pot giving you better heat distribution via natural convection.
    2. FMM comes in two versions (110V/1500W and 220V/2000W).
    Again, job well done!

  112. Double H

    @Erik – I had the same problem. Turns out that there were 3 problems. (1) even though I have the same relay as Scott, mine has to be wired differently than the schematic above. (2) My controller would not output voltage across pots 5 and 6 and (3) my unit has Autotune set to “0000” by default, and after I switched to using the the internal relay, I found that it MUST be to “0001” to work correctly.

    @Scott, you may want to check on this issue – my Normally Open and Normally Closed poles (the pole where you connect the heaters to the relay) are opposite to what you have. When I followed Scott’s schematic (with the correct orientation of the poles being placed as if you are looking at it from the top) my heater was wired to the Normally Closed pole.

    Back to Erik – if you have the CD101 controller, you may have to manually set Autotune to “0001”. The factory default is “0000”. Without autotune, it will heat way past the set value. You may notice that there is no button to push to get out of settings mode, but the controller will automatically back out to the normal PV/SV display mode if no buttons are pressed for about 30 seconds.

    It turns out that my controller just never put out adequate voltage from output 5 and 6 to trigger the relay. I compromised and disconnected 1 heater, and used the lower power rated CD101 internal relay. To wire it up I followed the wiring diagram from Alvin’s blog. (just search above for the link to Alvin Shcultz’s blog post about his own variation of Scott’s project. Having only 2 heaters makes warm up from tap water relatively slow, but it maintains temperature perfectly once it gets to the set value.

    On a side note, @Frank -people are here to DIY, not sort through spam.

  113. Erik

    thanks for the tips, I set the auto tune to 0001 and the OUT1 light stays lit however there is still no signal from any of the (3,4,5,6) posts, I am starting to think I have a defective PID.

  114. Double H

    @Erik – so has the behavior of the heaters changed at all, or do they just stay on continuously? If you get no voltage or current across 4 and 5 when out1 is on (make sure you bridge 1 to 4), then you probably do have a bum controller. Mine output on 6 was busted. QC on these things is ridiculous! Guess you get what you pay for.

  115. Phillip Kramer

    @Erik I ran into a similar problem with my build as well. What I found however was not that the PID was faulty, but rather I received the wrong solid state relay for my unit. I ordered a SSR that was supposed to be 8-32 VDC control input and 120 VAC load output, but what had arrived in the mail was an AC control input SSR. After contacting customer service, I received the correct replacement and everything worked just fine, and I have been cooking sous vide since…It can be hard to effectively communicate through the comments here, but hopefully something someone writes here will be of some use to you.

  116. bonafidebob

    Thanks again for the inspiration. I’ve completed my build and it works! Steaks were excellent. Here’s some feedback:

    There appear to be two different PID controllers, one with relay output (mine) and one with current output (described here.) I got the opposite one from the plans here, so I had to change my build. With the “Relay Output” version, instead of switching 12V on and off, it has the relay built in. This would be great, but unfortunately the built in relay is only rated at 3A which is only enough for one immersion heater. So I got a 120V 10A relay from Radio Shack and use the PID controller relay to switch that exterior relay on and off.

    I tried programming the PID to use F instead of C, but the temperature input from the PT100 was very wrong in F mode, it was 30 degrees low at least. Rather than try to figure out why, I just switched back to C.

    Instead of making an all-in-one unit, I built a dry box and a wet box. The wet box is built into a 4″x4″x2″ outdoor conduit box from the hardware store, and it contains two immersion heaters and the PT100 sensor. The dry box contains the PID and relays and switches, and has a standard AC outlet to connect the two.

    I also bought a 40 Gal/hr pump meant for a water fountain, and use that to feed the inside of the wet box. This keeps the box full and keeps the water circulating nicely. Even with only 2 immersion heaters, my 8 quart cooler heats up quickly, a couple of degrees C every minute.

    With the extra relay it made it easy to have two outlets on the dry box. Both are standard AC wall outlets, but one is switched by the main switch, and the other is controlled by the PID. So I plug the pump into one and the heating elements into the other, and get constant circulation but correct heat.

    This way I can use the “dry box” with pretty much anything that plugs in, so I could use it to control a croc pot or play with other immersion heaters.

    The PID programming is painful. Thanks for all the tips here.

  117. simulacrum

    The good thing about these plastic containers is they are designed to stack into each other, usually leaving a gap of an inch or so in between the two walls. So If you line another container with an insulating material on the inside and place your sous vide, water bath container inside it, you’ll end up with a more rigid, and better insulated water bath for an extra 5 bucks.

  118. Eric Lewis

    Would you consider building these units and selling them to the public? I’m currently searching the market for about three circulators, but have no ambition to spend the $3000 to buy them, nor do I find myself with the time to build them myself. Think it over and let me know, I’d be happy to talk price.

  119. CW

    I finished building this this past weekend using exactly the parts in your list. I am afraid I am pretty inadequate at programming anything, even a watch! Is there a simplified way to program the controller?

  120. SJW

    I made my immersion circulator with these plans, and it turned out great. It kept 15-gallons of water @135F for the weekend, with .1 degree accuracy. I used the PT100 probe listed here, but I got my PID and a solid-state relay from Auber Instruments:

    I didn’t use a heatsink for the SSR, since once the tank is up to temperature, the SSR is only on for short bursts. The Auber PID is super-easy to program. I upgraded my power-switch to a high-current 12-amp one, and used plastic epoxy that is waterproof and withstands 200C. Not as pretty as clear silicone & hot glue, but much safer.

    Made 3 racks of beef back-ribs for 48-hours @135F. They were amazing after a sear on the grill.

  121. John

    I saw this site and was overjoyed.
    I had found a precision waterbath in a local goodwill – the controller circuit was shot but found that the pump and the heating pad is working fine.

    So after purchasing all of the parts (apart from the heating elements and the pump I proceeded to assemble a controller. I found a really nice clear acrylic case that I installed a switched (but non pid controlled) ac outlet – for the pump.

    I assembled the control unit following direction and briefly toyed with the idea of a higher rated SSR – but the distributor advised against it as the unit I purchased was not set up for an SSR.
    Following multiple web sites/pdf’s I programmed the unit (hopefully correctly)for an RT100 selecting SL6 to be a 1 for heating. It would display the correct temp in C the out1 LED would light the internal relay would click …. but Nada.

    I checked the RAdio Shack relay for operation (it would click when voltage applied to its terminals. and Continuity would be between the terminal that did not contact before
    I even tried replacing the relay using the internal relay (re wiring so the AC would be switched by the internal relay)

    But I am missing something ….
    Help !!!!!!

  122. Matt S

    John – use the RKC pdf above to work out what output your unit should be: mine’s a “VM” unit so should be 12v output.

    Weirdly, I have the opposite problem to Bob: my unit reads out on Celsius but Fahrenheit is fine (or at least, closer to the correct temperature). I’m trying to work out if it’s consistently wrong but I don’t have anything to test it against apart from an IR thermometer. I’m worried that I’ve managed to miss-set a function now, but I don’t know what it could be. Does anyone else have a setting “CTr” under “Code 0001” in the initial settings menu (where you can change F/C units)? What did people set the SLL/SLH settings to?

    Many thanks for any help

  123. John

    Success – I think
    Just realised that the circuit diagram is a Birds Eye view not a “worms eye” and after trying 2 GFI’s I tried a regular outlet…. I got power I got heat I am now running a small test to see If I can bring it up to temp ……

  124. John

    So close but so far …..The relay contact I had used was the NC so of course the heater would come on.
    I checked the terminals 5&6 and even when the internal relay was clicking away there was 0 volts coming out – hence the relay would not trip.
    Any other suggestions Is there a software parameter that needs to be adjusted?
    I did select the correct Temperature sensor – the display is pretty close to a digital thermometer next to it. The OUT1 LED comes on the Internal relay clicks…..

  125. Matt S

    What’s the model number? Mine is a FK02-VM-AN meaning:
    K02=K thermocouple (can change in settings)
    V- Voltage out1 primarly heat-side output
    M – relay output 2 (cooling side)

    Don’t test for voltage across terminal 5&6, check for continuity (obviously, disconnect the load!). If there is, you connect it much like you would a switch. Otherwise- if there’s no continuity for 5&6 and no voltage across, then it’s a faulty unit!

  126. John

    Mine is labelled FK02 M* AN NN
    So reading that list it is a Relay out with no Out2?
    And excuse my addled brain here
    connect the line power directly to 5 with 6 continuing out to the heater?
    I shall try that this morning.
    Assuming it works (I know what assume means)
    My question here is how can I then isolate the internal relay and use a greater power demand heater – I think the internal relay is rated only for 3 amps.
    Thank you

  127. John

    OK I just checked when OUT1 is lit there is no change in continuity (it is open). I checked there was no voltage either.
    So it does look as if the unit is defective?

    One question. – which is probably obvious. Would previously connecting the control side of a SSR damage those contacts?
    (this was my first configuration)

  128. Matt S

    In theory, no, it shouldn’t: the SSR input won’t generate any current so it won’t be able to damage anything.

    Checking the manual, it’ll be 4/5 and 4/6 that will have the continuity between then. One will be on-when-out1-light-on, the other will be off-when-out1-light-on (it’s a single-pole-double-throw relay). So there will never be continuity between

    If it was a relay output, you could use the switch 110v output to connect to a higher ampage 110v input relay which would switch the load.

    So – connect 110v live supply to 4, connect 5 (*) to one side of a 110v relay input and the 110v neutral to the other relay input terminal. On the output of the relay, connect one side to the 110v live supply, and the other side to the live supply of your heating coils. So the internal relay is switching a live current to the input of a 110v relay, and this relay is switching the input to your coils. Be _very_ careful with this setup as if you get it wrong you’ve got 110v going where it shouldn’t. I can draw a diagram if you need it.

    (*) Connect 5 if 5 is continuity when on light is on, otherwise if 6 is continuity with 4 when on light, use this instead.

  129. John

    Thank you – I think it is working….
    I connected terminal 4 and yes we have connectivity when OUT1 lights up.

    So Getting brave I re inserted the SSR but I used an old 9 volt “wall wart” to drive it – the internal relay switches the SSR On – which in turn turns the power to the heater element. I am now running a test to see if it comes up to temp and stays there – wish me luck – No doubt I will have a thousand more questions Before I can get down to Actually cooking.

  130. John

    Woo Hoo Successs.
    I cooked two Mahi Mahi Fillets
    Recipe approximately follows
    “poaching liquid” about 3 oz white wine
    Small amount of Fennel seeds
    Small amount of Herbes de Provence
    Splash of lime juice – to increase acidity
    3 oz butter per fillet (cut into 1 tablespoon chunls & positioned either side of the filet
    Small amount Olive oil
    The liquid was blended with a fork.
    Fillets had been defrosted.
    Placed in Vacuum bags
    Put into the bath @ 58.1 C cooked for about 30 min (temped was at 58.1)

    Served over garlic smashed Potato (Yukon golds with skin on boiled with garlic cloves & tumeric mashed with sour cream)

    Sauce was about 3 oz butter 3 oz heavy cream 2 oz white wine tablespoon red peppercorns 1 tablespoon Vanilla Extract.
    Just reduced a small amount

    Top level cherry tomaoes sauted Olive oil & garlic then adding some fresh basil at the end of cooking.

    It was Very good!

    Tomorrow a Top Round beef cut!!!

  131. Matt S

    Bah, I’m having a miserable time with my unit – I suspect it’s faulty – the F reading is a bit wrong and the C reading is completely whacky. Anyone had and fixed this issues?

  132. John

    I found that the temp in C was starting to go wildly off of what I had programmed in (ok wildly and exaggeration but 2 -3 C) I then found that Autotune had reset to Off when the unit powered off (from the previous day) I selected turning on the autotune and the temp then stayed within very tight parameters.

    I also found that the display was off a degree or two from thermometers I had inserted to monitor the temp – rather than adjust the unit (next time) I just adjusted my set temp accordingly.

    One big thing is use a lid – It really makes a difference not only in reaching the set temp but also helping to maintain temps.
    I have not explored converting Display to F (most of my thermometers are “bi lingual”.

  133. Matt S

    Autotune shouldn’t stay on 1, it should run once (takes ~1hour) and the AT light will go off and the parameters on the PID (P, I, D, r etc) will be set correctly, and should save in memory after poweroff.

  134. @John Looks like you solved your problem. The only time I turn Autotune on is if I’m cooking in a different basin. Once I run autotune when the unit is attached to my hotel pan, it will remember the correct settings for good. However, if I switch to a smaller or larger pan, or if something enviornmental changes to affect heat transfer (ex. not using a lid) I’ll run autotune again as I’m pre-heating the water.

  135. Terry

    I’ve been following the directions as closely as my non-electrician mind can – and I’m close. Very close. My PID model is JLD-612 which has SSR output only. I’ve wired that to the relay & then from there to an AC outlet.

    My problem is that the power to the outlet never turns off at all. As the temperature changes the out light turns on & off correctly, but it doesn’t seem to have any affect on whether or not the AC outlet turns off. I’ve tried reversing the SSR output – and even disconnecting them altogether. No matter what I do the AC power is always on. Do I need to change the output to one of the jumper settings? Or can I do this with the SSR output?

    Any ideas as to what I’m doing wrong?

  136. John

    Now being an “expert” – waits for laugh track, Check your out put if your PID is set for cooling operation?

    Check your wiring… Using a Multimeter first disconnect the AC side of the SSR see if continuity is maintained or dropped when the output light is lit.
    My ssr has a red led that lights up when it is actuated – does yours… (that way you can see if the PID is sending out a pulse.

  137. JohnP

    @all. Have any of you found the need for a sacrificial electrode? I recently used some (nice) stainless steel saucers for espresso cups as weights, and after doing 151° F for 24 hrs, I found them to be caked with calcium deposits. Plus I am using a wire grate for my half size hotel pan ( and it is starting to rust. Any thoughts?

  138. John

    I just said the manual says … but then again my manual didn’t say anything about the “brain” transplant I did The use of White vinegar or CLR should help remove any chalk build up ……
    For the record I use tap water carefully “harvested” from the Might Mississippi …. this almost leaves a white chalk film on a drinking glass. ))))

  139. jim casey

    Hi Scott,

    I have built my machine, thanks for the idea! I cannot, however, get my PID controller to work properly. I continue to get an error message of all zeros, which my manual tells me that the polarity is connected inversely or above input range. Maybe you have some ideas, any help would be greatly appreciated as I have tried everything I can think of.

  140. Terry


    Thanks so much for your input. I’ve tried your suggestions & here are my observations.

    I have the PID set for heating – not cooling (although I’ve tried both).

    After disconnecting the AC I’ve tested leads 6&7 for continuity for the pulse – and when the output light shows there is continuity. There is an output light that shows – and it correlates directly to when there is continuity on 6&7.

    I’ve created a diagram of my wiring if it is helpful. It can be viewed at:

    Thanks in advance for everyone’s help.

  141. John

    With my new “expert” hat on here.
    Your PID has an SSR output (at least that is what the diagram says.
    But you appear to have it connected to a relay …
    Just my guess here is the relay an SSR or is it a relay?
    (the ssr I have seen (see previous reference to expert) Have 4 terminals 1 pair in one pair out) the one I bought had the pairs opposite each other.
    What are the voltage specifications of your ssr?(does it match the voltage output of your PID)
    I tested my SSR with a 9 volt power wart (from an old cordless phone) 9 volts from a 9v battery were not enough.
    So in your case my testing scenario
    Disconnect the SSR from the PID (keep the ac connected to the light bulb controlled by the ssr).
    Power the ssr (at whatever voltage & power it needs) if the light comes on ok … disconnect power to the ssr if the light goes out … well ssr works)

    Next measure power coming out of the PID does it fluctuate with the out1 coming on/going off? If it does measure actual voltage output (check manual) is that sufficient to power the ssr you have? If not you will need a new ssr at the appropriate voltage input and controlling amperage output.

    Just some “expert” suggestions.
    Defn Expert X=unknown quantity. Spurt=drip under pressure.

  142. I’ve gotten a few emails recently from folks reporting that eveything is wired up but the heaters just don’t turn on. Here are a set of troubleshooting steps to help. If you answer Yes to a question, move on to the next one.

    1. Make sure the OUT1 light turns on when the unit should be heating (when your set point is at least a few degrees above the measured temperature. If not, check your PID settings to make sure you’re in heating mode (not cooling).
    2. Does your relay click when the OUT1 light goes on and off? If not, your relay may be wired wrong. It’s unlikely (but possible) that you burnt out your relay.
    3. Is there voltage across posts 5 and 6 (might be different numbers on a different model relay)? You should read 3-12V. If so, and your relay still doesn’t click, your PID controller might not be pumping out enough juice. You’ll need to use a relay with a lower contact rating (like 3V) or an SSR (solid state relay).
    4. Is there a voltage across the output of your relay when it is clicked on? You should be able to read 120V (give or take) between the middle pin on your relay and post 2 on your PID controller.
    5. The problem is with your heating coils.

  143. Søren

    Hi Guys
    After about a month of waiting for parts I finally finished my DIY Sous-Vide cooker. I used the heating element of an old water boiler. 2300 W makes it pretty quick at heating up large portions of water, plus it can be mounted in the wall of the container i use. It’s really amazing how well it works, takes about 5-10 mins to get it heated to cooking temperature depending on how much water I use. Temperature is accurate to .1 degrees! 😀

    Thanks for a great post for amateur cooks 🙂


  144. jim casey

    Okay, I have confirmed that I have wired the unit properly. I cannot, however figure out how to program the PID controller, it heats the water but it still see a error. If anybody can help, I would appreciate it. I am using the CD101 PID controller.

  145. John

    OK what error are you getting?
    WHen you say that you are getting heating … is it controlled heating? (does the heat cut out after a certain point?) or does it just keep heating ….
    Most of the programming is “automagic” You just have to make sure you have set the PID to heating mode (SL6 I think) and also select the correct temperature probe (forget which one that was). I also selected the Auto tune and all seemed well …. (stable temp for 6 + hours.
    I did find putting a lid over the waterbath made the controllers job easier (maintained temps).

  146. Andre

    Very interesting Guide, i will definitively make my own, Thanks for this well detailed guide and parts list!

    One Suggestion:
    To avoid burning out the elements, you could install a small switch and floater located under the device that would only activate the elements if the elements are in the water. this way, if for any reason water is low, the element will shut off and not burn out…

  147. Didier

    I got my DIY contraption up and running and over the last month cooked steak, chicken and turkey breast with no problem.

    Today, however, I realized the temperature and dropped considerably from where I had it set. Further investigation revealed the PID overheated and the outer plastic shell near posts 4 and 5 warped and melted slightly. Needless to say the thing is toast. Could anyone wager a guess as to why this happened?

    I used the wiring diagram from this set up:

  148. Caleb

    Didier, you probably totally overloaded the contact amperage rating for that internal relay. Mine is the same, so I used it to pass through 120 volts to an external relay that is rated for 15 amps.

  149. Greg H


    I too feel an electrical shock when I touch the water. I happens ‘sometimes’ when I touch the water without touching anything else, but if I touch put my finger in the water then touch my metal faucet, I get a significant jolt. When it happened to me, there was no light on OUT1 and it is currently in AT mode. Can anyone speak to this?

  150. Greg H

    Hello all! First time builder, long time listener. I just plugged this device in tonight for the first time and am very impressed! (Thanks Scott!) I purchased everything as listed and I believe it is working as expected. However, I’ve combed through every post and am still having trouble with the PID settings. I know that this is a common question so if there is a link to describe the exact settings for this exact build that would be awesome. Here are some of the things I’ve noticed/questions I have. (Posted in part II)

  151. Greg H

    3. When I go set it to 1100 for the PT100, the Alarm1 light comes on and doesn’t go away until I set it back to 0000. Any ideas?
    4. It seemed to be heating fine and the water was getting very hot but before it reached the target temp of 50, I could hear the relay clicking on and off in unison with the Out1 light flashing on and off. The temperature did, however, continued to rise. Is this normal as it regulates temperature, is something wrong with my setup or can this be addressed in the PID settings?

  152. Manfred

    I am partially through collecting all the electrical parts to replicate the sous vide apparatus, however, the idea of using a plastic container did not appeal to me albeit the cost benefit. I chose the Ashland 15 Qt Stainless Steel Canner from . Granted, at $120 it is a lot pricier than a plastic container, but I want to get serious about sous vide and your electrical/electronic control solution together with a more solid “bath tub” appeals to me.

  153. Greg H

    After my post above about electricity being detected in the water I’ve done some more research and the results are disturbing. I’m am by no means an electrician but have consults with friends and feel confident enough in my results to bring it to the forum. To keep it short, there are two things I’ve been able to determine. Using a multimeter on the 20M setting I’ve been able to detect resistance when I touch one of the power wires and the metal heating coil. According to my friend, this is bad. Second, when I wire each coil individually, place it in the water, plug it in and measure the amount of voltage in the water I am always detecting some voltage (from 3 – 50V). I can’t believe that all three would be defective.

    Does anyone have some thoughts on this subject?

  154. @Greg H – Greg, Thank you for raising this concern and for your testing so far. I’m aware of a few dozen folks who have built this design, but so far this is the first report of electrical current in the water bath.

    Can you send me detailed photos of your machine and show how it’s situated in the water bath? Also, did you use the heating coils linked to in the parts list, or some other source? I’m thinking it may not actually be your coils that are leaking current, but perhaps a poorly-sealed water pump. You can email photos to In the meantime, can you try disconnecting the water pump and testing for current again?

  155. boogie

    Hi scott,

    i really appreciate your effort to make affordable sous vide appliance. I am from Indonesia..a big nation that perhaps you ever hear before..a it possible for you to build a sous vide appliance like you have for me..I will replace all cost and the shiping to Indonesia.thank you very much



  156. zgss29er

    Very inspiring all and all. How about pushing the envelope here a bit: I recall seeing a TV episode (with Keller I think) in which an immersion bath was set up with grape seed oil and the bath temp was around -15c. Not too dissimilar from the idea of the “Negative Grill”.
    How about a parts list for this??

  157. John

    Would a Peltier (sp) device be usable… I remember seing one covered in Ice. I think that they are a sadly under utilised device. Perhaps cobble one to gether using a Stainless Steel plate Attach one to the back and then via Transformer power it appropriately?
    I am not sure if they get cold enough … THis is starting to sound like another personal experiment.
    I know – just get my recirculator working I have a DIY chamber vacuum sealer also to be made (Have the chamber have the lid have a sealer I might be able to use just need to find a vacuum pump.

  158. Peter

    Looks really neat. I’m using a system with those norpro heaters, and I’m not looking forward to the day when mine burns/shorts out. Did anyone come up with an alternative heater option that won’t melt the plastic?

    Great project Scott!

  159. @Caleb Actually, I tested a few other types of heaters witht the same assumption, and I was wrong – in a melty, smelly, fire-y sort of way.

    For example, I tried using a heating element that was designed for a household water heater. The element gets really hot, really fast, and motion of the water isn’t fast enough to disperse the heat. A “shield” of steam built up around the heater, allowing the element to get hot enough to melt it’s way through the plastic housing, drop into my pot of water and pop the circuit breaker.

    For my new design, I have custom-made heating coils that don’t get (very) hot at the base. But these types of coils are hard to find off-the-shelf (I know, I tried!).

  160. Peter

    Nice work finding a solution. Unfortunately for my copy of yours, I’m not sure many places will custom make me a single heater! I’m looking forward to undertaking this project with my dad, since this should be a great way for me to learn some handy skills I’d like to have.

    I had tried a few aquarium heaters that I opened up and modified to override their built-in thermostat, but turns out they don’t get hot enough to keep the water above about 120 degrees. Dang.

  161. Greg H


    Could you do me a favor and post how the bucket heater works out? I too am looking for a Norpro alternative. On that note, has anyone found a successful alternative to the Norpro heating coils?


  162. Peter

    I sure will. I heard from someone else using it that it works fine. It’s 1000W, close to the 3x300W Norpro heaters. It also has a metal guard around the heater and shuts itself off if it runs dry (presumably not shutting itself off permanently like the Norpros). I’m looking forward to giving it a try!

  163. John

    After being quite happy with my set up (It was a modified water bath whose logic circuit had fried) I looked at its original construction and thought that perhaps a roaster could be used as the heat source & containment vessel
    is the result of a quick google search. They are also readily available at Goodwill stores. Set the internal thermostat to Maximum and use the PID to control the actual. They are designed for long power cycles some have a separate inner liner that can be filled with liquid and all that will needed to be added is some form of water pump aka aquarium pump.

  164. I’m tossing up the idea of starting one of these, or waiting for you to offer your v1.5 for sale.

    More specifically, have you done one with the receptacles for the heating elements and items (I love multitaskers). I saw a viewer put one together, and assume its wired much the same way as the heating elements in your wiring diagram. The plugs are more ideal as I’d like to use same unit for doing larger events (using a cooler/large container for instance) with a drop in caged heating element/circulatory device So the circulation and heat is emanating from the lower elevations of the water supply encouraging more of a convective flow.

    Have you found a bucket heater you can recommend?

  165. John

    I was thinking of the water circulation problem that others have encountered. I thought of a source of pumps able to handle hot liquids and came up with the Pumps used in a Dishwasher. They are designed to handle hot corrosive liquids (dishwasher soap solution) They should be readily available. The only negative I could see is they are perhaps too efficient in circulating water for the water bath.

  166. John

    Another success. I used a dry rub Paprika, Mustard powder Sugar and sage on a Pork But. Smoked it for about 2 hours then packaged it and cooked 165 for 6 hours. Absolutely melt in the mouth pulled pork. (served with a BBQ sauce).

    Next experiment is the treacherous path of chocolate melting & tempering using the recirculator and obviously keeping the chocolate & water separate.

  167. Mike

    Hi Scott,

    Trying to build this, and I’m waiting on parts.

    My PT100 came with just a Blue and Red wire, DEFINITELY no yellow. What does this mean? Did they slip me a mickey at Virtual Village?



  168. John

    I also bought a couple of Spare PT100’s from Virtual Village – I am going to use them to control differing devices than the re circulator. However If you look closely at the probes that wo of the wires have the same value – so I think it that the only one that matters is the one that is labelled Red (or the plus) the others I think are interchangeable.

    – Shoot me down If I am wrong here!

  169. Greg H

    @Mike Mike, are you saying that there aren’t 3 wires, or that there isn’t a yellow one? I believe my PT100 had three wires, one red, one blue and one black (with a yellow connector).
    @John I’m no electrician, but it was my thinking that the two wires that have continuity might be positive/negative. I have also noticed that I have continuity when testing the blue/yellow wire with my multimeter.

  170. Greg H

    I’m am still in search of appropriate PID settings. I have used the autotune, but I’m still about 20 degrees off. One thing I’ve noticed is that when I change the PID settings for a PT100 (code 1100) instead of default, the alarm1 light comes on and the output light goes off. Can anyone speak to this?

  171. Greg H

    Nevermind, I figured it out. When you change to PT100 it changes the maximum range of the SV to 40.0. You can change this to a higher threshold a voila! Obviously, the alarm1 was coming on because the ambient temperature was above the max temperature of the SV. We learn as we go!

  172. @Mike My suspicion is that you got at K-type thermocouple, instead of a PT100. The K-type thermocouple will work fine (just set your PID controller to use K) but you will only be able to get a resolution of whole degrees, not 1/10th of a degree Celcius. To test this theory, set your PID controller to K and see if you get an accurate reading. Then set it to PT100 and see if any configuration of pin settings will give you an accurate temperature. If not, check your order and see if Virtual Village may have goofed.

  173. Mike

    I just checked my emails, Yup, they goofed. I ordered a PT100. However, I can live with only 1 degree of accuracy, maybe… It’s threaded, you don’t happen to know the size do you?

    Thanks Mike

  174. Jack

    Hi Scott,
    I was in the middle of wiring my PID when I noticed that mine only has 10 prongs on the back (whereas the wiring diagram has 12) and is the model cxtg 3000. Did I order the wrong part and need a new one shipped or am I still able to work with this one?
    – Jack

  175. @Jack You might be OK. Check the pin diagram that came with your controller (or is printed on the side of the controller) against the pin table in the instructions. If your controller has the same pins, you should be good to go.

  176. Jack

    Checking the pins on the side the PID I have 1 & 2 for AC
    3,4,5 for the alarm, 6 & 7 for out SCR SSR. 8, 9 , and 10 seem like they are for the thermocouple. I did not see a designated spot to wire the relay unless I missed understanding my controller’s diagram.

  177. @Jack – Try measuring the voltage across 6 & 7. If it’s 7-12V, you should be able to use your relay. If not, you might have to buy an SSR. They’re more expensive, but they’ll work better than the relay listed in the parts list. Check for a 40A SSR.

  178. @Jack, Sorry, I should have been more specific. Set up your PID controller with the thermocouple attached, and set the set point to a higher temperature than the measured temperature so your OUT1 light comes on. Then measure the voltage across 6&7.

  179. Jack

    I set up everything up plugged it in and things went well. I my controller lit up and heat was going to my heating unit. When I turned it off at the rocker switch however I blew all the power in the house for about a second…. I take it this is bad. The rocker I’m using is a SPDT rated at 30amps and the heating source is an 1130 watt by Electra. Other than that I’ve followed the shopping list. Any ideas as to what I did wrong?

  180. Jack

    Things this afternoon went better. Everything is up and running with out shorting anything out. However after setting up my controller it is still 10 degrees off when I tested it in an ice bath. any thoughts?
    – Jack

  181. Matt

    Thanks Scott for putting up these instructions and all for answering questions. I got all my stuff a few days ago (exactly as specified) and just finished wiring everything up. Seems like my relay is not working. Or I killed my PID by hooking it up wrong.

    I initially hooked up all the wiring to the PID backwards, so, pins (Power) 1 and 2 were on 7 and 8, (Relay) 5 and 6 on 11 and 12, and (Probe) 10, 11 and 12 on 4, 5 and 6. I didn’t realize this until I set it up and plugged it in, the PID did not power up, but the pump and heaters did…

    I discovered my mistake and made the correct connections. This time it powered up fine. I was able to get the PID configured for the PT100 probe. The temp reading seems accurate and the Out 1 light cycles as expected, accompanied by a relay click. I can’t tell if it’s the internal relay or the external one. However, the heaters do not cycle, they are always on, and the pump works.

    I’m guessing my relay is bad, but also wondering if I have it wired correctly. In the diagram I’m not sure if I’m looking at the bottom of the relay and the pins directly, or at the top of the relay and it’s “x-ray” vision to the pins. I’ve tried both ways with no change in results.

    Reading through the other posts, I did check a few other things. I get no voltage across pins 5 and 6 on the PID.

    Any help is greatly appreciated. I’m so close…

  182. @Matt The wiring diagram assumes that you are looking at the bottom of the relay. Sorry for the confusion, I actually get that question a lot.

    Your relay *may* be fried, but it’s worth testing. First, put your multimeter across the two low-voltage pins for your relay (5 and 6 in my diagram). When the OUT1 light is on, you should get roughly 12V across those pins. If not, check that your PID controller is set to Heating mode (as opposed to cooling). If you’re still not getting 12V, your SSR output might be fried.

    If your PID controller has a 2nd relay output, specifically a 120V relay output, you can use that instead. Don’t connect your heaters directly to that output as they’ll pull to much power and fry it quickly. Instead, go find a relay with a 120V coil rating. Sometimes they’re called ice cube relays. Then connect the coil posts to the PID controller, and pass through 120V from your input power on the switch side. The wiring is a little messier, but it works.

  183. @Jack Check the manual for your PID controller. There should be a setting deep in the menu somewhere for a temperature offset. If your controller is reading 10 degrees off, just set the offset value to 10 (or -10) and you should be good to go.

  184. Jack

    Thanks I was able to adjust the calibration. However now my heater does not turn on. I read your post above about the trouble shooting and my relay and my heaters are working. However before I hooked up the heater and relay I was getting 13v and now theres no reading between pins 6 & 7. I also tested the between the relay output and pin 2 to see if it was at 120 and no such luck. Is it possible I fried a component inside the controller?

  185. @Jack – For testing your relay output, instead of looking for voltage, you should check for a closed circuit. Suppose your relay (not SSR) pins are #A and #B, just put your meter across them and look for continuity. Also, make sure that this output (probably OUT2) is set to Heating mode in the settings.

  186. Jack

    I checked my relay for continuity and it’s good. My controller is set for heating. When I wire everything together and turn it on the relay clicks on when the out light comes on (my model only has a single out light) and should be heating and the opposite when my set temp is lower than the reading. Yet still no luck. In regards to your trouble shooting advice above what happens when it does not read 120v between the relay output and ping #2 of the controller?

  187. @Jack Think of that relay as a switch. All it does is open and close. In order to get 120V out, you’ll need to pass 120V in. To do this, (referring to my wiring diagram above) jumper pin 2 to pin 3 and move the heater lead from the relay pin to pin 4.

  188. Mike

    Just got all my parts and, of course, I’m leaving for the beach for a week.

    Scott, What is your PID model code? The one I got through your link is FK02-M * AN-NN

    I’m asking because of all the comments about relay vs no relay. Fairly certain I need the Radio Shack relay.

  189. Matt

    I got mine working! I had to get a replacement PID, since mine was not activating the relay and the internal was most likely fried. I went with the PID from, and the SSR, same as commenter “SJW” above, so I blew the $75 budjet. I’ve made “sous vide” steaks before using the cooler method at, the ones made with this setup are by far one of the best steaks I’ve ever had. Next up, eggs!

    Thanks Scott, without your article I would have never had the inspiration to attempt this.

  190. Jack

    It works! It finally works. Thank you for your advice and directions. My problem turned out to be the common pin on my relay was broken at the base but the solder held it in place and was still giving me a 120v reading when I tested it instead of the wire

  191. Greg H

    @Steve Its not hard to make. Once you understand the concept behind it, it gets a lot easier. Some takeaways from my experience are as follows.
    1. Consider using a different heating element.
    2. Make a modular design so that replacing parts is easier.
    3. Use an SSR instead of the mechanical relay.
    4. Ask lots of questions!
    Here is a link to my design, taking from the best of all the posts plus a few ideas of my own.

  192. john

    Following the charts on cooking times ( I had great success this weekend.
    Using Lobster tails I removed most of the shell (apart from the piece at the end – for appearance). I placed each lobster tail in a vacuum bag added about 4 ounces of butter about 1 ounce of sweet white wine and about a tablespoon of vanilla extract (didn’t have any pods or I would have used that).

    So essentially poaching in a beurre blanc sauce 61 C for approximately 45 minutes.
    Wonderful !!!
    Lobster was poached just perfectly the cooking sauce poured over it

  193. Josh H

    Hey guys I’m about to try to build one of these beasts. I’m going to start off building a modular PID controller with plugs in the back to attach different heat sources.

    For my PID controller I ordered the D1S-2R-220. Here are the specs.

    I’m not very experienced with electrical and the schematics and broken english confuse me. I am wondering if you can wire a SSR to the D1S-2R-220 model or if it has something internal? I bought this without thinking and just assumed all PID’s were similar.

  194. Benwa

    OK – got this thing wired, heater coils are operating and have Temp controller set up according to instructions. Set the temp for a test run and when the set value temp was reached the Out1 light went out but the heaters remained on. Any ideas?

  195. @Benwa If the Out1 light is dark, then 5 & 6 should no longer be sending a signal to the relay. Verify:
    1) There is no DC output from 5 & 6 when Out1 is off.
    2) The relay is wired correctly.
    My guess is that the wiring is incorrect and the heater coils are simply on all the time and the PID isn’t really “controlling” them. Just a guess.

  196. Benwa

    When I had the 10A spdt relay wired originally with the rocker switch power attached to the N.O. post there was no power to the coils regardless of whether or not the Out1 light was on or off. I connected the rocker switch power to the N.C post and the coils came on. I thought perhaps I needed a Solid State Relay due to low voltage output. Now with the SSR connected I have power to the coils but they won’t turn off. I think the relay in the PID is burned up and i guess i’ll have to replace it.

  197. @Benwa Did you check for both AC & DC off posts 5 & 6 of the PID? Some come with internal relays and some do not. I’ve seen people mention in the past where thought their hardware was faulty only to find a wiring issue. Specifically, some of the CD101’s come with an internal relay (from what I hear) and, therefore, there is no need for an external mechanical relay or SSR.

  198. John

    While it is true that some PID’s come with relays rather than output for SSR. My understanding is the relays are only for about 3 amps controlling power. Most heaters are require much more. (Watts=volts*amps thus amps=watts/volts 1100w/110v=10 amps) so your 3 amp rated contacts will burn out really quickly.
    My PID had a relay output so I extended the circuit by using a 25 am rated SSR. I used the relay control to energise the SSR using power from a 9 volt wall “wart” transformer.

    This means I can now control bigger & better heaters without concerns of burning out my PID.

  199. mike42

    Re agitation: haven’t yet built anything, but it strikes me that the very cheap “milk frother” or “cappuccino frother” devices you can get for next to nothing might be OK. They’re powered by 2 AA batteries, and are essentially a DC motor turning what I would describe as a tiny whisk head very fast. Replace the batteries by a 3V supply, extend the metal shaft, and you have a low-power agitator which will work at any temperature. Maybe it could be moved to a different position from time to time. Maybe replace the whisk head by a propellor to move the water further (like an electric paint stirrer on a small scale). Picture here:
    Scale: 2 AA batteries fit in the handle.

  200. mike42

    Re sparks, mentioned as sometimes happening: any mechanical switch circuit (including electromechanical relay) can be suppressed by connecting a small capacitor rated for an appropriate AC voltage (typically 0.1 microfarad, 630VAC) in series with a small resistor (typically 100 ohms) across the switched contacts. Instead of worrying about getting the right values, you can buy inexpensive ready-made snubbers or interference suppressors. Theoretically values should be matched to the application, but I have used those given with total success to silence switches that produced interference due to sparking.

  201. Deeg

    @Greg H: I see you used the Marshalltown bucket heater; is it completely submersible? I.e. could you lay it down in the pan of water?

    Thanks to Scott for putting the original idea together and everybody else for adding their tweaks. There’s a good chance I’ll be making one of these.

  202. Jerome S.

    Hi there!

    I am currently making my mind about building my own DIY sous-vide cooking station.
    I am thinking about an ‘all-in-one’ appliance, or at least something that could be self-containing all the parts for easier storage in my tight kitchen.
    I am thinking about turning a compact beer cooler into a 2 uses bucket : first as a vacuum chamber, and then as the bucket for hot water cooking. After usage, all the parts should fit inside the cooler: vacuum pump, hot sealer, PID and water heater/circulator.
    Has any body ever tried that? I am thinking especially about using the beer cooler as a vacuum chamber: would it suppport the pressure?

  203. SimonR

    Hi Scott, thanks for publishing these plans, great work. I have built the unit as above, and I am using the Marshalltown bucket heater, but seem to be having some problems. When the heater gets current to it the temp reading on the PID starts to go crazy, when the current is off it starts to read normally again. When I stick one probe of my multimeter into the wall and the other in the water I get 120 V potential and 3-4 amps (AC). It seems that the heater is causing a current in the water, which would obviously mess with the thermocouple. My wiring is per the plans, except that I am using a SSR. Any ideas on what is causing this? A faulty bucket heater? Thanks.

  204. @SimonR I’ve heard a few reports of similar behavior before. As an experiment, please try this: switch the two power leads coming in to the machine. That is, swap the wire connected to the switch with the wire that connects directly to the controller. Then test the unit again. I’ve heard reports that the polarity of the wiring can actually cause this type of behavior, though (given my limited knowledge of wiring) I didn’t think polarity was such a concern for AC power.

    Also, with that kind of current, be sure to test the water again with your multimeter before sticking a finger in.

    All that said, the bucket heater _shouldn’t_ be leaking electricity into the water. It is possible that it is faulty.

  205. SimonR

    Thanks for the reply. I switched the wiring, same thing. I am using the JLD612 for the PID with a SSR. I think the thermocouple wiring is correct as it displays the right temp when out of the water. I also installed outlets for the pump (always on) and the heater (relay activated). Whether I plug the bucket heater into either of these outlets, or a completely separate wall outlet the same thing happens. I replaced the bucket heater and still get the same results with the temp reading going wild. It must be the thermocouple I guess. I’ll order a new one and wait and see. Thanks again.

  206. Mattch

    Hello… Thanks for posting the information and hosting this forum!

    I’ve almost got mine working. My OUT1 light turns on and off when going above or below the set temp, but my output is always 120v. I am not sure why it is not cutting the power when reaching temp? Bad relay perhaps?

  207. Bob

    wow… very cool. I think this is my next project. So far I’ve bodged together an old Haake circulator w/o thermostat with an old watco pid, and just yesterday ripped the guts out of a broken Lauda MT and replaced with the same PID kit you have up there. Any more news about the long term survivability of that pump? That’s the only part I see as a possible weakness.

  208. Mattch

    Tested my relay and it is working. When I use a 9v battery the relay switch clicks and 120v is sent to the heater. My 5 and 6 pins are not producing the 12v needed to click the relay switch… any thoughts?

  209. @Mattch You might want to try a Solid State Relay, if that is indeed the issue. SSRs don’t have the voltage requirements of mechanical relays. If you search this page you find links to ones that will work at decent prices. Hope that helps!

  210. Mattch

    Thanks for the feedback… got my issue resolved. This PID also has the internal relay. I wired hot from the rocker switch to the #4 pin and out from the #5 pin to my outlet where the heater connects. Same as Alvin mentioned above.

    Great stuff… looking forward to trying out my improvised version of this on my electric smoker!

  211. Greg H

    I have a question for the group. I constantly have to re-calibrate my PID (cd101 & pt100 thermocouple). I auto-tune every time but it marginally helps. Also, I have to offset the temp about 30F degrees. Anyone else having this issue?

  212. @GregH No, I’ve never had to recalibrate my unit. Is it possible that you’ve got a bad thermocouple?
    However, I noticed that you’re not using Celsius. I found that my PID controller is ONLY accurate when set to Celsius. I have no idea why, it should just be a mathematical coversion to F. But perhaps this is part of the problem?

  213. anthony s

    Is anyone using the CD101 with internal relay? I’m pretty sure that I need to run an external relay to control the heater. How are you powering your relay? I’ve been stumped for a few weeks, as this is the first time I’ve ever messed with creating something like this. Any help would be really appreciated. Thanks.

  214. @Anthony Are you sure you have an internal relay? If so, you shouldn’t need an external one. Remember, all the relay does is complete the circuit to your heating element when it needs to and breaks it when it doesn’t. If you have an internal relay, then do a continuity check with a multimeter. When the Out1 light comes on, then circuit should complete.

  215. anthony s

    @Greg H. I’m 95% sure I have one with the internal relay. I’ve done a continuity check with my multimeter. However, it says the internal relay is only rated for 3A, and I’m using the Marshalltown bucket heater. So I was trying to run an external relay because I’m afraid the current from the heater would be too much for the relay built into the controller.

  216. Greg H

    @Anthony Ah ha, I see your issue. If you search this site for *facebook* you’ll find a post by Alvin. He talks about internal relays a bit and his info might point you in the right direction. Sorry I couldn’t be of more assistance.

  217. John

    If you have a low amperage relay in your PID unit you might want to take the path I took.
    Use the internal relay to control power to a higher rated SSR. There might be an infintissemal delay in control But you can get a SSR that will happily switch 25 amps.

    I used a wall wart power brick for an old cordless phone.

  218. m

    I have the JLD612 PID controller. It’s supposed to be able to use the internal relay to control one heater (ie < 3A), but I can't get this to work. I can see approx 8V DC switching on and off on the internal relay.

    Does anyone have instructions on how to make that work?

    Thanks, M.

  219. @Anthony and @m I strongly advise you NOT to use the internal relay in your PID controller. Those relays are only rated for 3A. However, your heaters will pull over 7A. I’ve personally burnt out the internal relays on my PID controllers testing this method – they’ll work for a few hours, give or take, but invariably the extra load on the internal relay burns it out.

    Either use the DC output to control a relay (as described in the instructions) or use the internal relay to control a 120V relay that is rated for at least 9A.

    I don’t mean to be a downer about this, but as enticing as it sounds to use the internal relay, I promise it’s not going to last very long.

  220. anthony s

    @Scott Thanks a lot for the confirmation. I knew I should avoid using the internal relay. I just wasn’t sure how I was supposed to provide power to an external one. Seems like I have two options.

  221. kris

    Hey guys,

    I’ve been having a few problems. First, my heaters weren’t working and then I realized i wired the relay looking at it from the bottom per Pete W on 3/15. Then my heaters were always on (left top post when looking at it from the top) and I saw somebody said that I had the wire going to the pump/PID #2 on the wrong post. So, now when I put it on the other post (the right side when looking at it from the top), I don’t get any heat at all. Please help. I do have a multimeter, but I have no idea how to use it. Everything is using the exact parts/wiring as the original diagram other than my expirement with changin the wiring to the on the top 2 posts of the relay.

  222. kris


    Hey guys,

    I’ve been having a few problems. First, my heaters weren’t working and then I realized i wired the relay incorrectly where I had it wired looking at it from the bottom per Pete W on 3/15. Then my heaters were always on with the wire from the pump/PID #2 connected to the left top post when looking at it from the top and I saw somebody said that I had the wire going to the wrong post. So, now when I put it on the other post (the right side when looking at it from the top), I don’t get any heat at all. Please help. I do have a multimeter, but I have no idea how to use it. Everything is using the exact parts/wiring as the original diagram other than my expirement with changing the wiring on the top 2 posts of the relay.

  223. mattymonkey

    Thanks for the instructions. Found this after developing an interest in sous vide, but no interest in the cost.
    Just to let you know, I done this over in the UK but have made a device with a plug socket outlet to control a crock cooker.
    After a bit of fiddling, and confusion trying to interpret the pid calibration settings from Hong Kong, I managed to get it working.
    The only thing I dont have is the three terminal thermocouple, but it seems to be accurate enough using the two terminal on the autotune function.
    It cost me around £40 (inflated by having components shipped from the Far East).

    Good work

  224. Phil

    I was able to get mine working using a JLD612. I ending up setting it to have the internal relay as the PID controlled output. I have the internal relay hook up to a 12V DC power supply which is connected to the control side of the external relay Scott uses in his build. I have the heaters controlled by the external relay. So the internal relay clicks on which sends the 12V signal to the external relay which clicks the heaters on. It’s a little bit of a convoluted set-up but I was worried about burning out the internal relay. Also it gives me a 12V source which I will use to power a motor with propeller when the pump burns out.

  225. so i had my electrician friend make all the connections and we are all set up correctly, BUT… my PID is not putting out enough power to flip the relay on. it is only putting out 6.9 volts when out1 is fully lit. Im using a JLD-612 PID and am wondering if there is a problem with the programming as the manual says it should be putting out at least a constant of 8volts. i will begin looking for a smaller relay in the meantime, but if anyone knows if i can fix the relay power issue with some button pushing… that would totally rock

  226. Aaron

    HELP… I got my unit fully assembled and wired up to the point of hooking up my PID, the PID I got from the above link is the JLD612, does anyone have a pin out diagram that i could use? Having a hard time figuring out where to hook all of the wires into. Thanks for your time. I am so close to completing this project I can taste it!

  227. duncan

    Ok, so I just ordered my parts for this but I made a couple of modifications and I thought I’d put them up here to see if anyone thinks they’re totally stupid or maybe worthwhile.

    1) Instead of the relay above, I went with a solid state relay to eliminate mech. failure. It was cheap, but I bought a heat sink for it too, just to give a lil’ thermal protection.
    2) The one part I haven’t bought yet is the heating element. I think I want to use one from a whole house water heater and just feed it 120V. Hopefully this will allow it to be changed out easier.
    3) To avoid burning the element out, I want to put 2 stainless steel rods into the bath. These will be close together, but not touching, and be connected in series with the relay control. I think as long as the bath is not grounded this should work fine. Maybe I need some kind of amp. on this circuit to push it thru the water?

    I think this is everything, thanks.

  228. Greg H


    I too am having trouble getting the JLD612 to work with an SSR. I am using pins 6 & 7, which are labeled as SSR Output and it is working, but the temperature readout is jumping up and down a couple of degrees every second. It is also showing alarms on AL1 and AL2. Does anyone have any information on how to wire and program a JLD612 correctly with an SSR?


  229. Hi Scott,
    can you provide a wiring digram for using an internal relay to control an external 120v one? would the same arrangement work for a SSR?

    I have blown out my second PID, so i am revamping the case and relay system…thanks for your help!

  230. All,

    Just thought I would mention that I found out what was causing my reading to jump around on the JLD612. It turns out that you can fix this issue by grounding the outer wire-mesh shield of the thermocouple to pin #10 on the PID. If anyone else has this issue, give it a try!

  231. Hello everybody!! Buah, so close. So I don’t know how to enable the external relay on my PID. I’ve looked at the instructions a bunch but it’s foreign language. I changed the settings to those of Alvin Schultz’s but he uses the internal relay. Any help would be appreciated!!!

  232. mattymonkey

    is the system up and running but it is not switching on?

    If so and you are using a sloid state relay, make sure you are using the autotune setting on your PID and it should activate.

  233. Allright, system is up an running when using the internal relay. now i want to put in the ssr relay but can’t figure out the setting on the CD101 PID to change it from internal to ssr, or should that be taken care of by the autotune setting???

  234. Hello All,
    The connections are correct for the ssr relay, I get continuity over the ssr relay. My problem is with the PID settings and my manual which I can’t make much sense of. I don’t know how to set OUT1’s function to Heating, and the AT doesn’t seem to do it either. Thanks again for everyone’s patience.

  235. Aaron

    How long does the Auto Tune take to complete? I have been working on this project for at least a month and still cant get this working right. Do I have to use a SSR while using the PLD612? Why are the AL1 and AL2 lights always on?

  236. JD

    Hey all, I have been trying to get my system up and running for a while but cant quite figure it out. I have a 25a ssr and a CD101, everything turns on except for the heaters. I have tried putting autotune on and I am sure it is set for heating so I think i might have wired the relay wrong. Can somebody please post how they wired theirs? Thanks.

  237. Deeg

    JD, here’s the datasheet for your relay (assuming the digikey link is correct):
    It looks like polarity matters on your SSR and Scott’s wiring diagram has the polarity reversed–pin 5 on the PID is +12v and pin 6 is -12v–so you may have them reversed as well. So you should have:
    PID pin 5 –> SSR pin 3
    PID pin 6 –> SSR pin 4
    AC power –> SSR pin 1
    line to heater coil(s) –> SSR pin 2

  238. JD

    @Deeg I have continuity between pid pin 4&5 with out 1 light on. Should I assume pin 5 to still be + and make pin 4 -? And should i still have the line to the other heating coils going to pin 1 on the pid like in Scotts original wiring? Thanks

  239. Deeg

    JD, I’m not sure I understand you. If you’re using the same PID as Scott then you should be connecting the SSR to pins 5&6 on the PID, not 4&5. For the AC power, yes, you can have the other heating coil wire connected to pin 1 on the PID.

  240. Deeg

    Ah, I didn’t realize you have the internal relay; my bad. That makes it more difficult. If your external relay is the D4825
    then you need a separate DC power supply which you will connect to your PID and the external relay (I suggest something between 5v to 15v). You can use a cheap wall-wart; a thrift store near me has tons of them for 50 cents. (Alternatively you can exchange your D4825 for an A4825, which accepts AC power for the control signal.)
    I don’t have the PID with the internal relay so I don’t know what PID pins to use (it may be 4&5 as you said) but your wiring should look like this:
    DC +V –> PID relay “in” pin (pin 4?)
    PID relay “out” pin (pin 5?) –> External SSR pin 3
    External SSR pin 4 –> DC -V
    Pins 1&2 on your external SSR will stay the same as before. Does that make sense?

  241. Frank

    Having the same issues as Aaron above, have the JLD612, wired everything up like Scott directed and am not having any success. the AL1 and AL2 lights are always on, I can get the PID to recognize the PT100 the temp starts going up then stops and the pid clicks, do I need to go to the SSR, if so what do I need. How do I program the JLD612??

  242. Cliff

    Hey Scott,
    Old thread, I know, but I’m hoping you might still check this; I found these instructions ended up building something similar to Alvin’s with a separate controller box and heating/flow box. I have everything wired up (PID is a CXTG-3000 that’s similar to your model and a PT100 probe) and everything works fine EXCEPT I can’t get the temperature to read the correct values, I’m testing it against another thermometer (and room temperature) and it’s reading a good ~30-40F lower than it should be. I’ve tried swapping the wires on the controller to all 6 possible positions but I’m having no luck… If I swap the positive and negative wires I get the exact same temperature reading but if the third wire (I assume ground?) is in any other slot the PID reads an error so I assume it’s a setting. I have SL1 set to 1100 and I’ve tried all of the other probe values in the manual but it never gives me the right reading. I’m thinking it might be a faulty probe but I have no way of testing this.


  243. @Cliff – I’d check the manual that came with your PID controller. It’s entirely likely that the SL1 value for a PT100 probe might be different for your model.

    Also, if the temperature is always off by the same amount, you can adjust the Offset parameter to compensate.

  244. Cliff

    Unfortunately I have, several times actually, which is why I ultimately ended up cycling through all the available settings.

    Also, it’s not a fixed value delta, it’s definitely a sliding scale so I can’t just set the offset. It did just occur to me that I had set it to Fahrenheit though so I think I’ll collect some new data points to see if it’s a static offset in Celsius…

  245. Cliff

    Nope, looks like the thing is just giving me low readings no matter what I do, and not by a set amount. Time to curb it for the night and try again tomorrow… unless someone in the Seattle area is awake with a PT100 I can borrow, heh.

  246. MattS

    I had the exact same problem – it read wrong in Fareinheit and Celcius – the Celcius reading was more wrong! Turns out to be a faulty unit – contacted the seller and got a replacement that’s been fine.

  247. Cliff

    @Matt: Faulty PID or probe? I’ve done a few tests on mine, at extreme temperatures (0C or 100C) it gets pretty wildly off, for my normal cooking range (55-85) it’s only a little bit off so I just set the bias (Pb) so that my medium rare comes is “actual” and I’ll probably put a label on the unit with a lookup table. Not elegant but I’ll probably be building my own controller out of an Arduino board for V2 of this which I’ll have total control of…

  248. kris

    I’m gonna try this again.

    Hey guys,

    First, I’m using the exact setup/parts that Scott has links to. I’m not sure if I have an internal relay or not.

    I’ve been having a few problems. First my heaters were always on with the wire from the pump/PID #2 connected to the left top post when looking at it from the top and I saw somebody said that I had the wire going to the wrong post. So, now when I switched the Top Left to the Top Right, I don’t get any heat at all. Please help. I do have a multimeter, but I have no idea how to use it. Everything is using the exact parts/wiring as the original diagram other than my expirement with changing the wiring on the top 2 posts of the relay.



  249. john

    Latest success,
    2 T bone steaks 60.5 C for about 41 minutes – Lightly seasoned Garlic powder and salt. Then Surface browned (re thermalised) using ribbed cast iron pan – gave nice grill mark hatching.

    Melt in the mouth tenderness!!!,

    I read a book that said that all Sous vide cooked items should start at chilled temps – any comment on this?

  250. Ian

    I have built this according to the directions and using almost all the same parts. I have a JLD612 PID. The PID shows EEEE (out of range) on PV if I have it set to pt100 or pt10.0. I have tried switching the wiring and with and without the yellow (3rd) wire attached. I also accidentally ordered a pt100 that wasn’t long enough at first, so I tried to wire that one in and I still got EEEE. Do I have a faulty PID?

  251. mattymonkey

    you dont have to use chilled foods, but you cant use hot food.
    The issue is the vacuum sealing. Lower atmospheric pressure lowers the boiling point of water. If you put something that has been heated in a vacuum, the water will start to boil, destroying your hard work.

  252. John

    OK I realise as the the pressure drops then the “boiling” point also drops.

    But after the package is sealed and placed in the sous vide unit isn’t it also going to encounter the “boiling point” temperatures?

    Or is the concern that the water vapour is going to be lost to the vacuum pump during the evacuation process?

    I read where the purpose of the vacuum bags was merely to ensure contact of the bag to the surface of the item being cooked (the article suggested immersing item, to be cooked, in an open bag, into a water bath and using water pressure to ensure good surface contact sealing the bag and then placing in the heated water bath to cook).

    Has anyone researched the importance of the “sous vide” to the process?
    I have also seen sites in search of the perfect boiled egg – this uses no sous vide but just places the whole egg into a re circulator.

  253. Ely

    Hey guys, this all looks awesome and I can’t wait to get into sous vide cooking. I’ve spent the past two days reading through everything carefully and reading all the comments and I just have one question to the veteran/finished builders. What’s the longevity of this device? The sous vide supreme’s price is not prohibitively expensive but I’d much rather save some money and build something that could ultimately be much better, but not if it’s not gonna last. If I follow Scott’s directions and parts exactly, will this thing last me long enough/be fixable easily and cheaply enough, to be worth the cost and effort?

  254. @Ely – I can tell you that the longevity of the device is increased by not accidentally baking it in your oven 🙂 (terrible day in my kitchen). But, between the original machine and the replica that I rebuilt for MAKE Magazine, I’ve logged well over 250 hours on this little box, with no signs of deterioration. The component that is most at risk is the aquarium pump. It performs fine up to 80C, but at 85C you risk melting it. Luckily, very little sous vide cooking requires temperatures quite that high.
    If you’re considering the Sous Vide Supreme, be sure to check out my review – it has it’s strengths and weaknesses.

  255. Ely

    Thanks for the reply, Scott, that was exactly what I wanted/needed to get my hands (and credit card) working. Just to make sure I beat this horse to death, and then keep beating away, the parts and description listed above is the finalized version that should get me where I need to go? This absurd string of comments regarding relays and heaters failing got me a little paranoid that this thing is gonna be dead on arrival.

    I envy your notoriety, Scott, but I do not envy having to answer inane questions like mine. Thanks again for the help, you’re clearly a more patient man than I

  256. @Ely – not a problem. Yes, these parts and instructions are accurate and up to date – I’ve made revisions based on the comments thread (including just now!). If you’re still nervous, I’ve written a more detailed and more photographed version of the same build, which will be printed in January’s issue of MAKE Magazine. It’s all the same parts and steps, so you can feel free to start now. If you get stuck for any reason, the details in the article should help get you going again. Also, my inbox is always open for questions 🙂

  257. Aaron

    I have been working on this project on and off for the past few months, I really want to get it working. I am using the JLD612, do I need to use a SSR with this, does anyone have a wiring diagram for this. THank you for your time

  258. mattymonkey

    As far as i am aware, the type of vacuum pump available to the home chef can’t create a significant enough vacuum unless the temp of the food is very high. If you have cooked a steak to 90 degrees c and then vacuum it, I am sure it will boil, but at 60 in the water bath, it will be ok.
    The type and strength of vacuum used, depends on the desired results. Some dishes require a strong vacuum to create pressure on the food, but others only require the vacuum to remove the air to ensure good contact with the water and ensure effiecient heat transmition. For most home requirements (basic meat recipies etc) a ziplock back and a straw will suffice.
    If you want to see the geeky extreme of sous vide and explore the possibilities, get “Under Pressure” by Thomas Keller.

  259. Jay

    Hi Scott,

    Firstly, fantastic article, cheers!..
    Having read your tutorial i was inspired to build a waterbath myself, which i have duely done. However after soldering the last wire and programming the temp controller i’m having some problems:

    I have set a temperature to achieve (50 0c), the out1 light comes on, a click is heard from the controller but not my relay. On testing with a multi meter there seems to be no power reaching the relay and so the element doesn’t heat up, dispite the out1 light being on.

    I was wondering if there were any settings you had troubles with, as i couldn’t get my head around all of it… any suggestions would be really greatefully received!


  260. Hi Jay,

    The most common reason for this (you’re not gonna like it) is that your PID controller has only a relay output and no SSR (voltage) output. I’ve heard reports of some sellers misrepresenting their PID controllers as supporting an external SSR, when in fact, they do not. The click you’re hearing is almost certainly an internal relay.

    What model of PID controller are you using? If you look at the sticker on the side of the controller, it should say “Relay”, “Voltage”, “Relay + Voltage” or “Relay + SSR” or something along those lines. If your PID controller does in fact have a voltage/SSR output, make sure that’s the output that your external (blue) relay is connected to. Also check that the voltage/ssr output is set to Heating mode (in the settings menu for your controller).

    If your PID controller only has a relay output, you’re not totally SOL. You can return it, or you can use it’s built-in relay to trigger an external relay capable of withstanding the load of the heaters. I’d recommend getting a relay with a coil voltage of 120V AC, like this one Use the internal relay of your PID controller to trigger the external relay. DO NOT simply connect the heaters to the internal relay – it will burn out within a few hours of use.

    I hope this helps!

  261. Max

    Hey scott,

    I’m in the process of building. I have everything together, and wired in what I believe is the correct way. My only problem is that my pump does not turn on and it seems like the coils are not heating up. The probe is monitoring temperature correctly, but the pump and coils are just not working. I don’t have much experience with wiring, so I think that might be my problem and I might just need to rework that a little. I was wondering if you had any insight about what my problem might actually be. Thanks a lot.

  262. @Max,

    What your pump and heaters have in common is AC voltage. Depending on how you made your wiring connections, there’s probably a bundle of wires that starts with one of the wires from your power cord, then branches out to one side of the pump and one side of the heaters (or to the relay for the heaters). I’d double check that connection.

    Your PID controller doesn’t, by any chance, use a DC input (from a transformer or a “wall wart”), does it? If so, you’ll need to separately run AC power to the pump and heater connection points.

  263. Jay

    Ahh… Thanks for the help Scott. Indeed, the sticker on the side of the controller states: Output – relay. So i guess i’ll use the internal relay to control an external one. Will be 240v though as i’m in the UK! Will let you know how it all works out.


  264. Rachel Gerrits

    Hello, I built this cooker for a lab project. I am having several troubles making it work and I was wondering if anyone could help me. First of all my heating elements are not coming on. The temperature of the water bath is lower than my set temperature which should trigger the heating elements to kick on, and they are not. I hear the relay clicking which make me believe that is still working. I am not sure what is going. I wired it EXACTLY like the diagram said to and have checked everything like 4 times. I even tore apart one of my solders and redid it just to make sure they were all connected. Also, my PID is reading the wrong temperature. The manual is little to no help so I wasn’t sure if anyone could tell me how to calibrate it. Thanks!

  265. Mike

    Just FYI for the guys with PID controllers with built-in relays. You don’t need an external relay (and can thus connect the immersion heaters straight to the PID) SO LONG AS you make sure the total draw on the PID is not more than it supports.

    For example, I bought a CD101 off ebay. Listed in its spec sheet, it says the relay contact output supports 250V @ 3A. Total power is VxA, which gives 750 watts. Just make sure the heaters you connect draw less than this amount, and you’ll be fine.

  266. superrooster007

    What would you recommend in place of your PID controller that would allow me to set a program for fluctuating the temperatures at different times? I currently have a homemade coffee roaster, but I have to stand there and control the heat at different times (ex: 375 degrees for first 4 minutes then raise it up to 430 degrees for 8 minutes). I am going to build your immersion circulator, but I was hoping I can make the control unit dual purpose.

  267. Joe

    Just finished my first quarter of culinary school which got me even more interested in sous vide; I just ordered the parts on amazon and am excited to get started; anyone in San Diego that wants to see this done, I hope to have this made by the middle of January.

  268. John

    My latest experiment for Christmas isn’t strictly Sous Vide.
    However I am using my previously constructed PID Controller.

    I am attempting to emulate a “bargain basement” Alto Sham.
    This is an oven that is used in restaurants etc to make that wonderful carving roasts etc.
    I have used one and I have improvised one before but now I will use my controller to be even more accurate.
    Using an electric Roaster. Firstly “crank up the heat to about 400 F and let the unit pre warm. Prepare your Roast of beef (standing Rib aka “prime Rib”). I usually Stab it and insert slivers of Garlic & Rosemary. I rub salt and oil on the surface. Put it in an aluminium foil pan that fits inside the roaster (to help clean up & capture the juices for gravy). Put the foil pan into the roaster and put the lid on. wait 30 minutes (this does have a purpose apart from causing the wonderful Maillard reactions on the surface – it is recomended as a means of killy any Surface bacteria).
    Then unplug your roaster from direct power and now use your PID to control the unit. Using one of the vent holes in the lid put your temperature probe and use it to meter Air temps in the roaster. Dial in about 57 – 60 C and let the unit “do” its thing. As a counter monitor you can use a remote sensing probe thermometer to measure the internal temp of the meat. After about 2 -3 hours the meat should be perfectly rare – increase the temperature if you want to “murder” the roast to medium or even shudder well done.
    You can also use some hot au jus to cook the sliced meat for those individuals who insist on well done (keep the aujus just below boiling dunk the slice of beef into the au jus for about 45 seconds and viola they have a well done piece of beef while the rest of the roast is still done rare. Similarly Medium can be done by dunking for about 15 seconds.
    After the roast has come to the desired temp switch off and let the roast sit for about 5 minutes covered in foil…
    Carve & enjoy.

  269. So, perhaps in the 300+ comments somebody has already said this, but I didn’t have all day to read all the comments. Anyway, I think it would be really super awesome cool if you did a workshop for this project in the Seattle area. I totally want to make this, but I find it a little daunting without my PhD chemist dad looking over my shoulder. You could charge a fair chunk of change, and I’d still be better off than if I bought a “Sous Vide Supreme.” Since your article in Seattle Weekly, I’m sure there are a handful of us who would participate in a weekend workshop, and it would probably be pretty fun! (I guess the moral of the story is that I’m nervous that I’ll get a bunch of money and time invested in the thing and it won’t work because of some silly mistake I make. Then it’ll sit in my project room staring at me, making me feel guilty and sad, until finally I hide it in the closet to collect dust.)

  270. john

    Interesting observation.
    When using the Roaster and measuring Air temps.
    Although the PID would switch on the heating elements when the air temp would be at 57 C and switch off at the same temps as there was less thermal mass (water) the actual air temps would “bounce” 5 – 10 C. (the heating elements were switched off and on under PID control).

    Would there be some form of fine tuning that could be done to cut down on this variance?

    The Standing Rib was done perfectly though – I used a probe thermometer in the “thickest” part to confirm internal temps.

  271. Eric

    I am using the CD101, but I cannot for the life of me get it into auto-tune mode. I set the ATU to 0001, and go back into Run mode, but the AT light never comes on and the P/I/D values never get set. *bangs head against wall* I also no longer have the Self-Tune option at all. *bangs harder* Any ideas?


  272. Ixxorn

    Dear Scott, did you consider using the insides of a normal bathroom electric water heater (they call it boiler in hungary) it seems to be a natural choice for hating water up to 100 C. Also they come relatively cheap, and you can find lotsa used ones. Coupled with an aquarium pump you might be all set.

  273. @Ixxorn You’re right that a household hot water heater element is cheap and great at heating water. Unfortunately, the heating element is very poorly insulated from its housing, which means that the base of the heating element gets extremely hot. So hot, in fact, that it will melt straight through the plastic enclosure.

    However, if you mount the heater through the side of a metal hotel pan, so the entire heating element and its base is in contact with the water, that may dissapate the heat enough to make it safe. This would be a great design for heating very large basins.

  274. john

    Good idea for the large volume water heater, but I think another addition would be a piece of metal that would sit above the element and keep the bags away from the surface of the heater. Ascii Picture

    – – – – Plate
    Water Gap
    ======= Heater

    This would make sure the sous vide plastic pouches don’t end up in contact with the heater (maybe melting).

  275. Abe

    Am I correct in seeing that you use the SSR output on the JLD 612 PID controller to switch a mechanical relay? It does not seem like it is rated for driving this kind of relay, although the voltage does match up. Let me know if you’ve had positive results with this combination. Meanwhile, I will be using the internal relays to drive a smaller power load (see

  276. mattymonkey

    After building a version with a plug to power a slow cooker, I am currently building mark II.
    New version will comprise of two main parts. This time using a direct water heater, but will be plugging it in to the seperate unit with a plug, just in case of unfortunate burn out accidents.
    Making a case to hold the heater, probe and circulator out of angle aluminium and stainless mesh to protect the bags from the element. Will post pictures when complete.

  277. glassguy213

    Hi Scott,
    Great post. I have a few questions- I bought a PID controller that looks exactly like the one you show in your picture on ebay. It came marked as RKC brand but I suspect it is a Chinese knock off. Anyway, after reading your post I see that is says “RELAY” in the box meaning there is no SSR output. The instructions say there is an SSR output on pin 5 and 6, but alas I get no DC output there. So I was wondering which model PID you actually bought? I suspect that some of the models for sale on ebay are not suitable for SSR output, but mine is IDENTICAL to your photo so wondering if there are different models of same PID.
    I later bought one from (the link you have) and it works perfectly.

  278. @glassguy213 Unfortunately, a lot of people have fallen into this trap. Here’s the problem – the CD101 model comes in several flavors, all of which look identical, and all of which use the same instruction manual. Take a look at the Troubleshooting section at the bottom of this post to see why.

    @Deacon Yes, a float switch would certainly help ensure you don’t accidentally burn out the heaters. I considered one for this project, but it added a little cost and I didn’t see an obvious location to mount it safely. If you want to add a float switch to your build, just take one lead of the DC output that would normally go to the coil side of the relay and connect it through the float switch. DO NOT connect the 120V AC leads going to the heaters through the float switch. They aren’t rated for that kind of load, and passing 120VAC through the water bath has lots of other bad consequences (like injury or death).

  279. Weston

    First of all, Scott, thanks for the great guide!

    I just finished putting mine together and it is working really well. I can get very stable temperatures (+/- ~0.2 degrees) with a heating rate of ~2 degrees/minute. For those of you with the JLD612 (which is what I used) here are some solutions to a few issues I’ve seen in the comments.

    # Issue: AL1 and/or AL2 lights are always on.

    In order to fix this you need to change the settings in the “temperature and alarm parameter setting mode”.

    Hit “Set”, then enter “0001”, then hit “Set”. You’ll want to scroll through the list and set the “AH1” value to the same value as “AL1”. By default “AL1” is set to 90.0 and “AH1” is set to 80.0, so change one or the other so that they are the same. Do this for “AH2” and “AL2” as well.

    # Issue: PT100 Probe is showing “EEEE”

    This took me a bit to figure out. Go into the “0089” settings menu (by hitting “Set”, entering “0089” and hitting “Set” again). Put “Inty” to “pt10.0”. Exit the menu.

    Then double check your wiring. My PT100 thermocouple didn’t have red, blue and yellow like Scott’s, and instead had red, blue, blue. Plug the red connection into port 8 and then the other two blue connections into ports 9 and 10 (it doesn’t matter which one goes where). According to you might need to modify one of the blue connections such that it connects to the metal sleeve of the thermocouple cable if your temperature reading is unstable. I didn’t have this problem with my setup.

    # Issue: Relay isn’t turning on (or off) and you are *positive* you have it wired correctly.

    As far as I can tell, the relay that Scott uses here doesn’t work with the PLD612; at least it doesn’t work with my setup. I checked that the relay was working properly by manually switching it on and off with a 9V battery and everything worked exactly as expected, but the PLD612 just wasn’t outputting enough voltage to properly switch the relay (in my case it was outputting about 7V across ports 6 and 7 and not 8V as stated in the data sheet). I’m still looking for a better relay, but in the meantime I’ve put together a very hacky solution; I’m using the built-in relay (J2) at 120V, through a 120V AC to 9V DC converter (from an old cellphone). The ~9V put out by the adapter is enough to actually switch the relay used in this guide. Again, I’m only using this as a temporary solution, but it works as an interim solution.


  280. @Weston Thank you so much for this! That information is most certainly going to help out a lot of folks. Very clever workaround with the 9V transformer as well! My advice for a permanent solution is to buy a Solid State Relay (SSR). They typically have a much lower activation voltage. I’d recommend either of these:

  281. John

    I was reading about the concerns of overheating. Perhaps the use of a thermal fuse (Radio Shack). A catalogue number I have is 270-1321 (this is rated for 229C 10A 250vAC).Put this in series with your heater element – attached to the underneath of your heating pan. This will then cut out before any real damage happens.

  282. David

    I see that you have upgraded your equipment for version 1.5. I was wondering what PID you selected as well as what your other internal upgrades were. I’m looking at using a commercial immersion heater and MAYBE an Omron PID. Is it necessary that I go the commercial route? Have you had matched sucess with cheaper elements? Any advice would be appreciated. Thanks

  283. @David The PID I’m using for my newer models is from Novus Automation. ( The temperature performance is the same as the CD101, but the buttons, display and menu system are a little more friendly.

    For the heating elements, I don’t think it’s necessary to go commercial. These immersion heaters actaully do a great job!

    @Archie I haven’t tried 4 elements, but if you do, I’d suggest using a solid state relay (
    ). The additional heater will put extra load on the relay, so you’ll want something beefy to stand up over time.

  284. Julian

    First of all, I’d like to thank Scott for the plans and troubleshooting as well as everyone else who posted information here; I wasn’t sure if I could tackle this project but I’ve started gathering the parts and I’m very excited to build it!
    Now, a question:
    I just received my PID from LightObject (the JLD612 that you link to) and noticed that at contact #11, instead of a screw, it has what looks like a resistor sticking out of the hole. Because the sticker on the side describing the contacts showed a screw next to #11 as well, I was concerned and called LightObject. The fellow I spoke to there assured me that this is in fact the way is is supposed to be and what looks like a resistor there is a small temperature sensor used for the auto-setting functions and that I would be able to attach a PT100 thermocouple without problems. However, on your (Scott’s) wiring diagram, it shows one of the three leads from the thermocouple going to that contact point. Should I be concerned? Should I just not attach that wire? What function does that temperature sensor serve?
    Thanks again!
    – Julian