2 March 2010: DIY Immersion Circulator (SeattleFoodGeek Mk. II)

Aschultz wrote:

Sous Vide

Seattle Food Geek PID Controlled Immersion Circulator. Mk. II

This is a version of the Immersion Circulator described here. Per Scott’s thoughts, I have made the unit into a generic temperature control device. In addition to cooking Sous Vide, I will also try to use this to control  temp on my Alton Brown Terra Cotta Flower Pot Smoker.

Parts list

Immersion Circulator:

PID Controller Module:

Misc Tools/supplies:

  • Hot glue gun
  • JB Weld
  • Rotozip or other means of cutting metal/acrylic/plexi
  • Soldering iron and solder
  • Electrical tape
  • Wire Strippers
  • Multimeter (tool that measures voltage, current, resistance)

You’ll also need a vessel to do your actual cooling in. I bought a 8″ plastic service container from my local restaurant supply store. Rather than buying the matching lid, I opted for a new plastic cutting board that fits over the entire container…it was a buck less and both can be used for other kitchen duties (no Uni-taskers!) This cost me $30.81, but you can also just use a large pot on top of a cooling rack. (which I have used for eggs, etc since it is a smaller body of water to heat and hold at temp.


Immersion Circulator:

1) Making the frame.

Cut metal strip into four pieces to create base the same size as your piece of plexi-glass. Mark the metal strips and drill holes for assembly. Cut the threaded rod into four 9″ pieces, and assemble the immersion circulator base using the threaded rod as vertical posts.

Place the frame upside down on the piece of plexiglass to mark for the holes that will mount the plexiglass to the bottom metal assembly. After drilling the holes, test for fit. The plexi will sit on top of a nut and fender washer on each post. This will allow you to adjust the height of the immersion heaters and temperature probe to heat more or less liquid as necessary.

2) Mounting the heaters.

After confirming that the plexiglass will move up and down the posts with relative ease, remove it and cut holes for the heaters. With this design, the heater holes need to be large enough for the power cords to fit through. Disregard the long rectangle at the other side of the plexiglass, learn from my mistakes…measure twice and cut once.

Because the holes will be larger than the white part of the heaters, you’ll need to secure them to the plexiglass. I used JB Weld, after your adhesive dries, fill in the gaps with silicone. I used a marker to align the coils of the heaters.

After the JB Weld dries (over night) I filled in the gaps with silicone.

PID Controller Module:

1) Assembly of the “Face” of the controller.

Mark and cut holes for the PID controller and toggle switch. To allow for the most room for the outlet I put my controller in the northwest corner of the bottom of the acrylic container. The lid will be used as an access hole for wiring and sealed later. At each stage, I dry fitted the components to ensure that there was adequate room for the next component.

2. Cutting holes for the GFCI and Thermal TRS Jack.

Next, Mark and cut holes for the GFCI outlet and 1/4″ Female stereo phono plug (that will eventually accept the temperature probe. You will need to notch the east and west sides of the rectangle for the GFCI to allow for mounting screws.

Now you’ll have to modify the orange mud ring to enable the dog ears to grab the acrylic container. without modification, the mud ring will not go thin enough to hold securely against the sides of the container (it’s made for dry wall:) I just used a rotozip with a conical grinding bit to take a notch out of the screw holes that hold the dog ears.

3. The PID module dry fit:

4. Convert the PT100 Probe to a 1/4″ Stereo Phono Plug.

Cut the ends of the thermal probe off. There are two blue wires, these are both the same signal (ground) I was very careful to keep them organized, but I later discovered that it is unimportant. Slide the strain relief parts of the 1/4″ Jack down the wire in the order shown…make sure you do this before you start to solder the connections. AFTER you slide on the strain relief, solder the connections to the terminals on the phono plug.

Wrap some electrical tape around the metal jacket on the PT100. Re-assemble the strain relief, when you’re done it will look like this:

5) Making the female side of the 1/4″ jack.

Repeat these steps for the female side of the 1/4″ Jack. This will get mounted inside the box when it’s complete.

My wiring diagram for the 1/4″ Jack(s).

6) Drill a hole for the power cord to enter the enclosure.

After you drill the hole, pass the power cord through so that the plug comes out of the lid.

7) The rest of the wiring…

Here’s where I ran into some trouble (hence the fewer pictures). I guess there are so many types of PID controllers on the market and many variants of even the same models. Thanks to another commenter on SeattleFoodGeek.com, I figured out that my PID had a build in relay…so my wiring looks like this:

Set Up

Immersion heaters go into water (be sure coils are covered by water), place PT100 (also plug in PT100 into the controller module) and Pump in water. Keep the PT100 a reasonable distance away from the heaters to prevent a false reading. The second thermometer in the pictures was only used for testing.

PID Settings:




(at this point, pressing “Set” will cycle through the following settings. I think that the auto-tune function will set the first group of settings for you.)

ARU: 0000 This is the “Auto-tune” setting. Set it to 0001 the first time you test the unit.

P: 001.0

I: 0049

D: 0012

Ar: 0025

R: 0010

Pb: 000.0

LCK: 1000

<<Press and hold “Set” and “>

COD: 0000

(at this point, pressing “Set” will cycle through the following settings. I think that the auto-tune function will set the first group of settings for you.)

SL 1: 1100. This is for the PT100 probe.

SL 2: 0000

SL 3: 0000

SL 4: 0000

SL 5: 0000

SL 6: 0001

SL7: 0000

SL 8: 0000

SL 9: 0000

SL 10: 0000

SL 11:0000

(Now it will bring you back to the “COD: 0000” Screen. Changing this to 0001 will offer the following settings)

COD: 0001

(at this point, pressing “Set” will cycle through the following settings. I think that the auto-tune function will set the first group of settings for you.)

SLH: 250.0

SLL: 000.0

oH: 000.1

dF: 0001

(Now just let the unit time out until it brings you back to the normal screen)

Press “Set” to set the desired temperature, use the “<R/S” button to move the cursor and the up/down arrows to change the values.

Sous Vide Away!


Helpful Links.

Seattle food geek Sous Vide Build.

PID Controller Manual.

A Practical Guide to Sous Vide Cooking.


41 thoughts on “2 March 2010: DIY Immersion Circulator (SeattleFoodGeek Mk. II)

  1. hi, i’m trying to duplicate your project except instead of an outlet i have the other half of the power cord (where my slow cooker will connect eventually). right now the unit powers on but it won’t power whatever is connected to it (i’m using a lamp to check right now). do you have any ideas? i’ve checked the connectivity between terminals 4 and 5 (while off) and got nothing, but checked 4 and 6 and also got nothing. seems 4-6 is NC so there should be something right? feel free to email me, thanks.

  2. On my PID, 4/6 are NC, and 4/5 are NO. You’ll want to connect to whatever is NO on your PID. Some PID’s have a 12v trigger out of 4/5 that would require a separate relay like Scott has built on seattlefoodgeek.com.

    You should be able to check for continuity/voltage across 4/5 when the out1 light is on. if you are going to wire a slow cooker directly, you should be getting ~110v over 4/5 when out1 is on.

  3. thanks, i went out and got a (non-solid state) relay, but it still doesn’t work… do you have an updated drawing with the relay you put in?

  4. “SousVideMagic or Auber PID-controllers use Semiconductor Controlled Rectifiers (SCR) instead of a mechanical relay. If your relay should wear” – PedroG.

    My question is what do you think about his comment and will you use the SCR instead of the mecahnical relay?

    Also are you willing to make another to sell? Let me know i am really interested in your Heating Immersion Circulator.

    • at this time, i am not ready to produce sale units, i think Scott (seattlefood geek) may be nearing production though…i need to work out some kinks in the design…even then it would be much more cost effective to build your own. I would not sell my unit for less tha n $250

  5. @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 http://fhupiora.fhupiora.home.pl/JLD612Manual.pdf
    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?

    • i had seen that manual online too…it dosent adjust the decimal point. is the OUT1 light on when you’re getting voltage (that’s good) you can try raising the SV temp to see if out 1 goes out, then you should stop getting voltage.

      I will post an update once i get the new PID fully up and running

      • Well, I actually did all the requisite troubleshooting with the multimeter, and while I know my knowledge of SSR’s is very limited, I think that my SSR arrived faulty. The PID works fine, I actually had it working properly with the built in mechanical relay, but had already decided to go with a SSR after hearing about your troubles with the first PID. I checked contorl power voltage coming from the PID and I am getting the correct corresponding voltages when OUT1 is lit and when it is off, but the SSR is still somehow applying 108 to 109 volts to the receptacle when OUT1 is secured, which should not be happening since the PID is ordering the SSR to turn the receptacle off. Oh, and I don’t know if you had seen it, but someone mentioned on Seattle food geeks blog that the PT10.0 setting on INTY might give you the tenth degree increment you were looking for, although I cannot verify at this time. I believed PT10.0 to be a setting for another type of thermocouple, but I have certainly been wrong before, so you might try that just to see if it works. I’m going to try to exchange my SSR this week for a new one, but out of curiousity, where did you get your SSR?

  6. Looks like I’m gonna build pretty much what you built, with the following 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 you built, I’ll do what you did… For now, I just want a nice, stable setup on a specific storage bin that can’t tip over, etc.

    I just ordered my PID controller: http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=110520671430

    What I don’t get about the PID controller is that it says it has a 24V power output and a “transmitter output” that can be configured in a variety of ways. I haven’t seen these features and don’t know if it’ll be useful to me or not. All I want to do is drive a relay in the same manner as Scott at Seattle Food Geek (so I don’t dump 9A through a 3A relay), and his diagram indicates “-12V” on pin 5 and “+12V” on pin 6. This could be construed as 24V, or it’s 12V and his “-12V” really means “12V ground”. In either case, the relay he has is rated at 7-9V on the winding. I guess I’ll see when I get it. Based on the manual, I can’t even tell how you’d configure the output as a power output or simple relay contacts. The Ebay page doesn’t tell me what the model number is, so hopefully whatever manual comes with the controller will clear things up.

    Anyway, enough rambling. Alvin, the system layout that you put together is almost exactly what I was thinking about doing, and seeing your setup confirmed that it’s the direction I want to go in. I’ll blog my build as well and share with everyone like you two have.


  7. Hi Alvin,
    I am trying to make my project work properly.
    I have followed the instructions on Seatlefoodgeek but when i power the unit on, my heating element continues to heat once it reaches the set point. i followed the Pid setup provided on your page and i can now set any temperature and i can set a point of a degree (52.5degC) (before the pid would only go to 40 deg C).

    I am wondering if my pid also has a built in relay and if so should i try your wiring setup.
    It looks to be the opposite to the one i have followed. I have attached the manual for the pid unit as the terminal configuration diagrams are on page 4.


    The unit is named RKC CD 101

    I hope you may have an answer for me as i am a chef in Australia where this cooking procedure is vurtually unheard of and i hope to astound my diners of the amazing food created by sous vide cooking.

    Thank you,


    • Hi Mark,
      Great to hear that you’re going to bring Sous Vide “Down Under”!

      Here’s a couple of things for you to check:
      Disconnect the coil leads from the PID to your external relay. turn the unit on, if you hear clicking, that is the sound of a relay built into your PID (like mine, and you should use my diagram, not Scott’s). If you do not hear clicking, it could be that you are connected to the NC terminals on your relay, or that there is a failure in your relay, or that the relay coils are not getting enough juice to switch the relay.

      You should be able to test your relay with a 9v battery.

      If you are going to be Sous Vide for a commercial environment, please take time to read the practical guide to Sous Vide for time/temp explanations. other than that, I recommend Eggs, Steak, and short ribs…actually nothing bad has ever come out of my immersion cirrculator!

  8. Hi Alvin,

    Thanks for the heads up. Turned out that the relay wasn’t strong enough. With that fixed the unit runs beautifully. Had to change the water pump to an air filter. cooked it after cooking lambs beast for 18 hours. The results are quite amazing.



  9. Alvin,

    Thanks so much for your work on this. I’m trying to morph your build with Scott’s, but my limited knowledge of electronics is hampering me significantly. I also have the JLD612 – but I’m also trying to use an external relay (per Scott’s instructions) to avoid your problem of the internal relay burning out. So at this point my wiring doesn’t look like yours – but I don’t know if the diagram was for the JLD612 or the previous PID.

    My diagram is here: https://docs.google.com/drawings/edit?id=1YhjBDe2zNMK3o0rZ6Zd2MsMb8Je2DbQW1HyZ2I7uvKM&hl=en

    I hear the clicking, have continuity etc. when expected. But my external light (my initial test device) never turns off at any time – even if I disconnect the SSR outputs completely.

    I’m sure that I’ve done something elementary wrong in hooking up the SSR output of my PID and the external relay. Can you let me know if the published diagram is for the JLD612? If it is then I’ll change it and the settings to match your web page.

    Thanks in advance!

    • Sounds like you have the control setting on the JDL12 set up wrong. There are settings for external relay, internal, and external ssr

      ~Alvin Schultz

      • Hello Alvin, I have a CD101 PID and wanted to find out what PID settings to change for an external ssr relay.
        Thanks for the hard work.

      • Hi John,
        I have replaced my CD101, but am in the process of building a new unit with an external SSR. I’ll post an update once I figure it out…hoping Scott from seattlefoodgeek.com will help with the wiring. Out of curiosity, which SSR are you using?

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    • Check my recent post for a large wiring diagram for the jld 612 with solid state relay.

      Did you have specific build questions?

      • This has been very helpful, but i have one quick question about the JLD612: What poles do the three wires on the Pt100 thermocouple mount to? When I connect mine and set it to the proper input setting i get an error message.

        What I do not understand is that when I have my Pt100 wired in and set the settings to k type it shows a temperature.

        Any suggestions?

      • I have a new diagram posted on this blog- working from my mobile I can include a link later if u need it.

        Input error means you have wires crossed, probably blue and yellow. The pt100 will read on the k setting but not accurately, you want the setting “p10.0”

  12. Hey I seen your new diagram. Is there anyway you can make me a diagram like that but with the actual heater coils instead of the gfi and with the other relay (the small blue one with 5 leads on it). Please help , I cannot figure this out! Thanks

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  14. Hi Alvin, I am trying to build a Sous Vide machine very similar to yours with a built in GFCI, but I was wondering whether you had any bigger pictures of your work. Especially for the wiring diagrams, I can’t make them any bigger to see what’s going on. Please let me know if you’d be able to send me your pictures.

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