Jan 16, 2011
$50 DIY sous vide immersion heater/circulator
Updated and abbreviated. Still solder-free.
After using our $50 sous vide for a few months now, we have made some updates and modifications. I also think the length of the previous post makes the construction seem more complicated than it is. This is so simple, it can be finished in less than an hour, and will really only cost you $50 (depending on your need for tools).
NB: hardcore hackers, we have a MAKE guide!
As always, build at your own risk.
UPDATE: We now have a kit to build your own sous vide controller for $80! It requires soldering, but we think it produces an elegant and convenient result.
- Norpro 559 immersion heater (Amazon)
- PID controller JLD612 (Lightobject)
- K-type thermocouple (Lightobject)
- Ziploc vacuum (sous vide) pump and bags (Amazon)
- Elite A800 aquarium air pump (Amazon)
- Aquarium air tubing (Amazon)
- 6 inches of wire (around 18 gauge)
- Electrical tape
- Solderless spade and ring terminals (18 gauge)
- Wire crimping/cutting/stripping tool
Step 1: Power cable
The PID will act as a switch for the immersion heater. In order to attach the heating element to the PID we need to cut the cable for the heater in half crosswise about 12″ from the heating element. Now we have two separate cables. The plug cable should be 24″ long.
The heating element and plug cable is made up of two wires. On both cables, separate these wires on the ends and strip them about 1/2″ (Fig 1).
Now we’re just going to deal with the plug wire, attach small ring terminals to the ends (Fig 2). Tug the ring terminals to ensure they are securely attached, and wrap the connection in electrical tape. Attach these ring terminals to connectors 1 and 2 on the PID controller (Fig 4).
Step 2: Thermocouple
While the thermocouple (at the tip of the screw) is stainless steel, the screw attached to it is not and will rust in the sous vide bath. As such, we’ll use electrical tape to wrap the screw and all parts of the wire that might come into contact with water (Fig 3).
Then attach the thermocouple spade terminals to connectors 9 and 10 on the PID controller (Fig 4).
At this point, cover the back of the PID controller in electrical tape and plug it in. The PID should read EEE.E at the top.
To get it to read the correct temperature, hit SET and enter “0089″. Then press SET when “Inty” is blinking and scroll up or down to “µ” (this is secretly a “k”, for the K-type thermocouple). Then press SET. Press up so “outy” is blinking and press SET, then change the number to 1 (this sets the PID output to the built-in relay). Press SET again and scroll to “End.” Press SET to exit.
The PID controller should now display the temperature on top, and may start to click. Unplug the controller, and we move on!
Step 3: Heater
We are almost done, just a little bit more crimping to go. Strip and crimp small spade terminals onto the end of the heating element cord (Fig 7).
Then attach the wires from the heating element to terminals 2 and 14 of the PID controller (See Fig 5, 6, 8).
Take the 6 inch piece of wire and attach spade terminals to each end. Connect one end to terminal 1 and the other end to terminal 13 of the PID controller (Fig 5-6).
Finally, tape a popsicle stick or chopstick to the back of the heating element (Fig 9). Since the plastic nub attached to the back is short, this augmentation this will allow the heating coil to reach further into the water.
Step 4: Bubbler
The bubbles produced by the aquarium air pump effectively mix temperatures into the layers in water. Just plug the pump in an adjacent socket. In order to weigh down the end of the air tubing, we wedge the end between the tines of a fork. Easy!
Step 5: Start cooking
Everything tech is done now, just set up your sous vide and bubbler with a pot full of water. Because the heater is fairly low powered, it may save time to put the pot on the stove to heat it to temp first. It’s also useful to cover the pot in saran wrap or aluminum foil.
- Use our PID tuning parameters to reach the target temperature faster.
- Keep the PID controller and water pump elevated, to avoid damage by water spills.
- Make sure the thermocouple is secure and deep in the water. If it comes above the water level, it will register a temperature that is too low, and the PID controller will turn up the heat indefinitely.
- Make sure the coil of the heater is below the water surface, but watch out for water spilling over the edge from the bubbles.
- Remove some water before putting food in to avoid spilling.