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DIY Sous Vide Heating Immersion Circulator for About $75

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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

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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.
    IMG_0444
  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.
    IMG_0460
  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!).

Troubleshooting

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 scott@seattlefoodgeek.com.

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”

Ok. Now I hear the relay clicking. I had the outy and rd settings correct already.

Now the al1 light is always on. And the out light is blinking in relation to the relay clicking. So now I’m assuming theres a problem with my temp “0001” setup. Any pointers there?

Scott,

I followed the instructions with my contractor buddy, I would have been lost without him but I have a problem. Pump is on, Out 1 is on but the pid reads 25 on top and the bottom numbers start at around 200. The water bath was measured at about 60.

Chris

Scott,

A couple more things. The wires to the thermocouple didn’t have yellow or blue only red. Should I reverse them? Or is it a matter of setting the PID? I cannot understand what the instructions mean. I’m just a Chef with two nice Polysci machines at work and would like one for the home. Good job, you’re the best.
C

@Chris: what model PID controller are you using? Do your heating coils get hot (touch them carefully underwater – you’ll know if they’re on)? When you say your thermocouple only has a red wire, does it have any others as well?

My guess is that you don’t have a pt100, but instead have a K-type thermocouple. That is fine (the machine will work, but with less accuracy) but you’ll need to set the thermocouple type to K in the menu. Then you should get accurate temperature values. Or, order a pt100.

Scott – I was sent to your site by a friend who is a chef at my favorite restaurant. I’m building him one as a gift. I’m going to do something similar to what andrew did, with the plugs so the heating coils/probe can be swapped out to keep the box away from water.

Any thoughts on this heater? http://www.amazon.com/dp/B000BDB4UG/?tag=seattlefoodgeek-20

Also I have the same PID as Julian, with the resistor at #11. Anyone figure out how I’m meant to connect the 3-connector probe with this there?

@Scott I was wondering if just one of those would do the trick rather than trying to rig/wire up 3 of the smaller ones. It says it’ll do 150 and up near boiling. But, I just read a review on Amazon that said it didn’t work well for sous vide. Guess I’ll stick with the 3 you’re using, but I want to think about how to make them replaceable.

Scott,

I got the PID straight off the link to amazon link. There is no name but a model CD101. I did check the coils and alas no heat. I did have to search for the thermocouple and it does have three wires but only a red and two blacks. I really appreciated the quick response.
C

@Abe thanks looked over your site and looking very straightfoward. But I have the (more accurate?) PT100 with 3 connectors, and just ordered an SSR last night. Was wondering if just one of those heaters would do the job – looks like it should. @scott any input on using ONE of those heaters?

All,

thanks to the great explanation of Scott and the help from all above I have managed to get my sous vide working like a chame with indeed .1 deg accuraccy!! One question though that I couldn’t find. What is the best way to do a callibration of the unit? I have the tet612/jld612 version. Is the best way to set the input at 110 wait till it stops increasing i.e. 100 deg c. and then see what the temp says? 102, i.e. adjust the unit with -2?

I’ve managed to get it together finally (I’m using it to control a rice cooker) and ran the auto-tune function (at 35degC) and it held at that temperature perfectly. Now, I’ve set it to 55.5degC and once it got close, I put in a steak. it has since climbed to over 57 and keeps pulsing the heater rather than stopping. Any idea why this might be happening? I added some cold water to bring it back down and it did it again (and again). Did the autotune not work properly?
Thanks very much!

PS: For those with the JLD612, you don’t actually need contact 11, your pt100 connects to 8, 9, and 10 with red, yellow, and blue respectively.

An update: after deciding to just let it run without trying to control it, it seems to be hovering within .3 degrees of 57, still pulsing the heater.

@Patrick, the JLD612 has an auto-tune function that can be run by holding down > until the AT light starts flashing. It will take maybe a couple of hours, but it stops flashing once it’s finished. I can’t guarantee that this is correct though given that it doesn’t seem to be working well for me.

It sounds like a lot of folks are having issues with the JLD612 and autotune. I’ll order that model controller and test it out. In the meantime, remember to run the autotune routine under the same environmental conditions in which you’d actually use the machine. It learns how much “ON” time it takes to raise the temperature, and how quickly the temperature falls afterwards. Using more or less water, taking a lid on or off, etc. can mess with it’s accuracy a bit.

Hey Scott,
Thanks a bunch for this design. I went Alvin Schultz’s route and built a modular brain with plugs that (once it is summer and not -20 out) I am going to use as the controller for an Alton Brown-style smoker. I just got the box and stuff, but so far have just duct taped my heating elements and thermocouple to my bin.
Tonight, I finally assemble it fully, I am very excited!
So far, I’ve done 48 hr sous vide beef shank that was more tender than my favorite braised short rib recipe & last week my friends told me that the sous vide rack o’ lamb was the best they have ever had.
I am thinking of using the design to control some other things too….
Any idea if there are plug-in cooling elements that might be analogous to the immersion heaters?

Thanks again!
Sachin

The autotune on the tld612 actually works perfetly. Just press and after some time the blinking stops and the autotune is finished. mine actually stays within +- 0.1 deg after auto tuning in a new environment. The question I still have is how to calibrate the unit. Seen the temp is so critical and having a unit being acurate to within 0.1 of a degree, it would be unfortunate if the temp is 2 deg off (which it was in my non scientific method..)

@Julian I was told by a friend familiar with the PT100 is the yellow lead isn’t actually needed at all. It can be used in higher-end environments for calibration but is the JLD612 actually using it for that?

If you can get a 12v temp controller, I don’t see why not. the pump and SSR are both operated by appr. 12 volt. you will still need higher voltage for the heaters, although you might even be able to use those 12v car water heaters. don’t know what that would do for the total current. you might need very expensive SSR’s for the high amps…..

i have used the 25A SSR supplied by lightobjects for my unit and noticed that it gets pretty warm during use over extended amounts of time…I noticed on their website it recommends a heatsink be used in conjunction with this unit. Should i be concerned since i’m well below the 2000W rating for this unit or should this box be ventilated to alleviate the heat generated by this relay? Thanks in advance!

I’ve noticed that my SSRs get warm as well, but I’ve never had a problem with them actually overheating. A little ventillation could help, but I wouldn’t worry about it too much unless they start approaching 100C.

Awesome idea and build Scott. Just afew questions. Have you or anyone else pushed the upper temp limit of the norpro coils? Do they get the water hot enough for any sous vide use? Also i was just curious if having the sensor so close to the heating e

@etienne the nopro coils will get the water plenty hot, right up to boiling. I limit the upper temp range on my controller to 85c to protect the pump from damage. Because of the water circulation, the distance between the coils and the probe isn’t a problem – on commercial machines, they’re even closer.

@Brent, SSR current ratings usually include a generous heatsink. You need to derate them if you do not use one–a 25A supply might only be rated to 7A at room temp without a heatsink (see http://www.auberins.com/SSR%20Series-RS1A.pdf ). It will be derated further at higher temperatures (ie, in an enclosure).

If you want to keep your SSR within ratings (and I highly suggest you do), move it out of the enclosure and add a heatsink! Here is one for only $10, http://www.auberins.com/index.php?main_page=product_info&cPath=2&products_id=45

Good luck!
Abe

@ Scott Thanks for the info. I’m ordering all my parts today and am looking forward to getting into sous vide. On a side note, i was telling my dad(who happens to be french) about this and he’s quite sceptical. I looking forward to broadening his horizons.
Cheers,
Etienne
P.S. Congrats on getting into Make mag. A worthy accomplishment.

HI Scott, Thanks! I have gotten most of the parts, still waiting for the PT100 probe.
I have : TLB612 PID, 1 GIF 15a-125v outlet, 1 15a-125v outlet, 1 15a switch, 3 Norpro 559 heaters, SPDT Relay. But want to get a SSR and a heat sink not sure what will work with this PID. I am a chef and have read over the blogs over and over and just confused. Please help?

Do you think there is a way to wire the alarms to sound if the temp gets to high? And i was also thinking about a built in timer. All in all a awesome plan and I can’t wait to build mine!

thanks,
Zack Baker

Hi Scott, thanks for the excellent tutorial!

I am having some trouble: I was not able to get a CD101 with SSR out, only with relay out. I purchased the Omron LY1AC110 relay that you suggested and followed the alternative wiring schematic. The temperature is assessed by the CD101 and themocouple fairly accurately and when the temp is below the set temp, the green OUT1 light does go on.

The problem is that the heater coils do not go on and the LY1AC110 seems to not “click” on. I’m going over every contact and make sure it’s wired correctly. I’m not sure of a safe way to test the relay with AC, so I’m open to suggestions. Thanks! =)

-Jonathan

I forgot to ask: would you mind going over the pin-outs for the LY1AC110? And are you positive that I should be using pin-5 on the CD101 to trigger the relay coil?

Thanks again! 🙂

Do you think running a single Marshalltown 742G Bucket Water Heater instead of the three heater units would turn out better?

Ok, sorry to spam your blog with my problems, but I tested the relay with AC from the wall and it works fine. Somehow it’s not being triggered by pin-5 (which I /think/ is the CD101’s NO pin for the internal relay). Open to suggestions! I also just donated if that helps 😉

I don’t know what I did, but it works now! wahoo!

Now just one more problem: I can’t seem to set the temperature higher than 40ºC and I haven’t been able to decipher an temp limit in the manual. Thanks for any help!

Best,
Jonathan

I used the Jld612 controller, but only get 6.48V going out to the SSR. Any ideas on why this may be happening? I don’t get any of the clicking you describe, other wise the unit seems to be working. thanx

@Don Yes, it was part of the Code 0001 submenu. This was my first real DIY electronics project and i’m incredibly happy with how it turned out.

I tested the relay using a 9v battery and it kicked the heaters on, so I’m not getting enough juice to the relay. I’ll try and pick up a new relay on the way to work today. I also contacted the seller of the PID to see if there’s a way to increase the output for the relay.

Got mine up and running, complete with lighted power switch and I converted the probe connector to a three-prong audio jack so I can swap them out.

BUT – I might have damaged my probe. During testing I accidentally dropped the probe into a cup of water. When it is in liquid, the temperature jumps around all over the place. When it’s not in liquid it’s stable, but the wrong temperature. Does this sound like a shorted out probe?

@Zack – yes, just make sure your relay is rated for the extra power. Shouldn’t be a problem.

@Paul – Never heard of that issue, but I’d be more inclined to think the connector might have something to do with the problem. Perhaps try getting the end of your probe really hot (with a lighter or a small torch) to try to evaporate any water left inside. Then, try testing with and without your connector.

@Scott – will try that. The reason I think it was dropping it in the water was it seemed to work properly until I dropped it in.

@Scott – ok figured it out. The fluctuations only happen when the heater is plugged in so it must be some kind of interference, either with the heater or the wiring in the box.

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