DIY Gadgets Sous Vide

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!

998 comments on “DIY Sous Vide Heating Immersion Circulator for About $75”

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.

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?

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.

Very interesting machine! what about the precision of the temperature and the stability, what kind of equipment did you use to verify there parameters? Did you make a long period trial of your immersion circulator?


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!

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.

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.

Also, with the design you have now, if a bag were to touch the elements would it melt/break? a guard perhaps to prevent that would be great. some sort of wire basket?

Dear Scott,
Several of us are meeting in Atlanta on 2/21/2010 to do this together. Would love to be able to reach you w/a question that day! Lol, we’ll see how it goes! BBQ will be on hand.



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!)

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!

You rock!! I’m sure the SeaTac folks would be concerned if they saw it, and one might wonder if you cross wires, you wind up back in the 1950s with a young George McFly, but who cares, as this is a truly awesome device!

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.

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!


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?

@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.

@Scott, do i have to ground the GFCI outlet? would that mean running a 3 pronged plug to the wall and connecting the ground directly to the outlet?


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.

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!

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.

@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…

@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!

FYI- the “AT” or “Auto Tune” setting is your friend…forget about the Jay Z song…mine finally seems to be holding a temp.

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?

@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.

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.

@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!


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).

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.

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.


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!


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.


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.


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