Picture of Sous Vide Oven Controller
2014-06-22 16.09.31.jpg

Instead of cutting apart a perfectly good Crock Pot this build will show you how to build a controller your appliance you can plug into. This modular approach means you do not need to buy a second appliance. If you have an old rice cooker in the cabinet you can make it a sous vide oven.

The tricky part of sous vide cooking is keeping the water at a precisely regulated temperature. Most cooking appliances have the ability to turn the heat down but regulating it with any accuracy is not possible without automation. Fortunately temperature controllers are not expensive and they are as easy to use as a regular oven. An eBay search for temperature controller 58 194 should give options under fifteen dollars ($15USD). Amazon also has the same controllers. The advantage these devices have over a dial on the side of a slow cooker is that the temperature controllers use a thermometer to monitor the temperature.

The versatility of these controllers is also impressive and since this build is being made very modular it is possible to use this appliance for things other than cooking, such as automating a window fan. A short list to get the brain gears turning is shown at the end of the instructions.

The goal of these instructions is to help you build a device that is highly functional, rugged, and looks good on your counter. All the wires are hidden away and sealed up so a few errant splashes from the sink are not cause for an emergency.


  • Temperature controller. eBay. Amazon.
  • Slow Cooker*
  • Old computer power cord*
  • 6x6x4 PVC enclosure*
  • Duplex receptacle
  • Receptacle cover
  • Cord-tight connector
  • Electrical lock nut for cord-tight connector
  • Thermometer for comparison
  • 3.5mm plug, mono
  • 3.5mm jack, mono
  • Small wire whisk
  • 2 #8 nuts
  • Shrink tubing 3/32inch diameter
  • Wire nuts. Preferably lever locking nuts
  • Electrical tape
  • Solder
  • Timer
  • Wide masking tape
  • 100% silicone sealant

*Alternatives to these devices are given on the last page

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What about temp controller?

All in one. Plug and play. No need to find all items you listed and then drill and cut...

24Eng (author)  maozai83yesterday

GREAT! I don't see why it wouldn't work. I checked that it can reach boiling so there isn't any temperature range issue. Just buy a hot plate or analog rice cooker and you'll be good to go. I still recommend putting the thermometer in a whisk or something to protect the probe from touching cool food.

Excellent find, thank you for sharing.

Hmm a very interesting concept, nice Job!

24Eng (author)  TrollFaceTheMan5 months ago

Thank you. A lot of your 'ibles have caught my eye.

dushu7 months ago

Have made something similar:

24Eng (author)  dushu7 months ago

I had originally planned to make this with an Arduino Micro Pro and a 16x2 that you used but once I saw inexpensive temperature controllers I went that route to simplify the project. Mine doesn't have the humidity sensing of course but in a project at my last job I went into excruciating detail with a temperature and humidity sensor for grain drying. Your code is very clean and straight forward, nice job.

dushu 24Eng7 months ago
Thanks, also, as mentioned in my blog - I can use this as a framework to make a bluetooth controlled switch / or a motion controlled switch....
gafisher7 months ago

Very nice work, and an excellent ible! The only suggestion I'd offer would be to add some sort of circulator, perhaps an aquarium pump or similar, as the temperature of the water in the area of the food, the heating element, and the probe is unlikely to be the same if you depend on convection alone. Lacking that, a quick stir with a spoon every few minutes would be a good idea, especially the first 15 minutes or so after adding food. But that's just icing on a very nice cake.

24Eng (author)  gafisher7 months ago

The idea of a circulator occurred to me but I couldn't think of a suitable method. An aquarium pump seems iffy because they are not meant to handle near-boiling water. But I agree that right after adding food the water temperature will not be even.

gafisher 24Eng7 months ago
Your very creative use if the small whisk gave me the idea of putting a small motor at the handle end of one of those, driving a small propeller ar the basket end, perhaps using a piece of plastic tubing as a shaft. Just a thought.

This is a rip off of a different instructable. Correct me if I'm wrong: from the user burkelashell. Don't get me wrong. It's a nice ible, good work, but you need to give credit to the original user who thought this up.

24Eng (author)  nathanaloysiusbash7 months ago

I hadn't seen that one but we certainly had the same ideas for parts. I'm glad you posted because people can see that a single receptacle is all that is needed whereas I used a duplex and wired the second one to be hot all the time. Receptacles are at a premium in my kitchen and finding covers for a duplex is simple and inexpensive.

I hadn't seen burkelashel's build before you brought it up. In fact I drafted and printed a 1:1 paper model of the controller so I could find a suitable enclosure at the hardware store.

Really nice work. I love the 3.5 mm plug and the whisk. I'm going to link to your ible from mine so everyone can take the best ideas from both.


24Eng (author)  burkelashell7 months ago

Thank you. You do nice work, I guess great minds...

My bad. Guess I shouldn't have jumped to conclusions when I saw the enclosure box. I made the controller from burkelashel's ible. Thinking back I guess that was the only appropriate sturdy box I could find too. Again really nice ible. I actually like yours better. More detailed There really cant be enough sous vide ible hacks out there. That square hole I cut out with a dremel. Very useful tool.

theboz14197 months ago

Should look at a Heatermeter, they are a lot smaller and you can get a 3d printed case for them.. I had made an older HM to control my smoker and recently I upgraded to a newer version. So, I took the old one added a SSR to it and it can now be used to Sous Vide or anything else. The following pics show how big they are.

24Eng (author)  theboz14197 months ago

That is a really robust system! And very compact.

dgateley7 months ago

Thanks, especially, for the whisker idea and for the wiring diagram. Got all the parts already but wasn't sure how to wire the controller.

carlos66ba7 months ago

Thank you for sharing this. Is it sufficient to have a controller like this (on-off) or is it necessary to have a PID controller?

24Eng (author)  carlos66ba7 months ago

Excellent question and I go into some of that in my blog. The short answer is that a PID loop is overkill for a project like this. Another issue is that a PID loop, which can apply throttled power similar to a light dimmer, would only work well with resistive loads. I think that one of the charms of this build is that it can work with so many different types of 120V appliances like fans which do no play well with light dimmers.

carlos66ba 24Eng7 months ago

Thank you for the response. Note that a sous-vide pot is essentially resistive, so would work well with throttling. Also, in amazon there are PID temperature controllers for as little as $25 (not much more than the one you used). So, is it necessary for sous-vide?

$25? Type in 'digital temperature controller' on ebay. A lot of PID's for under 15 dollars.

24Eng (author)  carlos66ba7 months ago

True, the heating elements in kitchen appliances like rice cookers and slow cookers is resistive so a PID controller utilizing a triac would work. It would provide better heating so if you only want to use it for resistive loads it is a good choice. There is a trade off, you can't use the PID model with motors so you lose the versatility of using this with a fan but you will get a more even cooking temperature by using the PID controller.

Would you post a link to these controllers so other people can benefit? Some of the PID controllers on Amazon even have two displays so it is possible to view the set point of your temperature and the current temperature reading.

carlos66ba 24Eng7 months ago

Here is one for $25:

24Eng (author)  carlos66ba7 months ago

That is the one I was thinking of too but when I read closer it still uses a relay. The PID must calculate how long to keep the relay on as opposed to how much of the wave form to chop. This controller would be excellent but you still have to buy a thermometer sensor and the programming would be much more intense. Like a sliding scale, the high functionality of this controller comes at the sacrifice of simplicity. Thank you for putting this link up, now others can decide on their own.

robothead7 months ago
good job
Shanem217 months ago

The whisk is a stroke of hacking genious...

carlos66ba7 months ago

Congratulations on appearing on hackaday!

24Eng (author)  carlos66ba7 months ago

Thank you!