Johnson Temp Controller for Idiots (me)

OK, I kept reading about Johnson temperature controllers and was of the impression that it involved somehow modifying the fridge itself, so have veered away from these things (for now). I am now a bit confused. Does the fridge just plug into the controller, with no modification to the fridge, and the controller kills the power coming from the wall socket when the temp hits a certain temp? If this is the case, I feel like an idiot for not having bought one of these before. I have an old fridge I was going to use for a tap set up but would absolutely use it for fermentation control if this is how the Johnson controller works.

This is the model I'm looking at right now.

http://www.midwestsupplies.com/johnson-digital-temperature-controller.html

Yes.

If you want to pretend to be smart, you can buy the controller and an extension cord and wire it yourself for a little cheaper.

The refrigerator or freezer does just plug into the unit. You adjust the temperature of the fridge/freezer to the coldest setting then the controller just turns the power on or off depending on the temperature setting and what the sensor is measuring. The only alterations that you might need to make is for getting the temperature probe inside.

chumprock said:

Yes.

If you want to pretend to be smart, you can buy the controller and an extension cord and wire it yourself for a little cheaper.

Click to expand...

Thanks. I honestly feel like a goof-ball for not figuring out earlier that this is how it works. I think I am going to order this, delay my planned brew for this weekend, and use the time to plug up the tap hole in the top of my old fridge and insulate it so I can do a good fermentation inside. This fridge is so old that it doesn't even have a temp setting. I believe it just runs 24/7 when plugged in.

Here's a good link for a diy on the Ranco controller. Saved me about 30 bucks to diy it.

https://www.homebrewtalk.com/f51/how-ranco-etc-111000-wiring-video-331745/

Jon73 said:

Here's a good link for a diy on the Ranco controller. Saved me about 30 bucks to diy it.

https://www.homebrewtalk.com/f51/how-ranco-etc-111000-wiring-video-331745/

Click to expand...

Thanks. I'm lazy, though. If finding parts and assembling is going to take me more than 30 minutes, I'll pay the extra $30. I also am an idiot when it comes to electronics so I think I will be happier with the Johnson.

You don't need to modify the fridge to put the probe in (although I'm sure if you did it right it would look prettier than mine). But I run the probe right in through the top of the refrigerator door with good results.

Johnson works great. Plug and play. If you are keeping the fridge in the garage, you might want to consider getting a dual temp controller. One for something to keep it warm and another for the fridge motor.

Came across thread and was having same questions, could you elaborate on the fridge in the garage scenario?? I have that set-up( creating), and have a side by side fridge/freezer, if i understand you correctly place both to coldest setting and then set-up the controller right? what would a dual temp set-up accomplish? Thanks!

Ripn914 said:

Came across thread and was having same questions, could you elaborate on the fridge in the garage scenario?? I have that set-up( creating), and have a side by side fridge/freezer, if i understand you correctly place both to coldest setting and then set-up the controller right? what would a dual temp set-up accomplish? Thanks!

Click to expand...

You're correct. Plug your fridge/freezer in, have it set cold, and everything else is adjusted through the controller. Dual-stage controllers are useful if you need to power two separate devices, such as a freezer and a small heater, to keep your temps where they should be.

So for example, if it dips down below fermentation temps at night in your garage, a two-stage would benefit you by powering the heater at night and the fridge during the day. I ferment in my basement where the temps are pretty consistent year-round, so a single-stage (cooling) controller is sufficient. Hope that makes sense.

Also, I'll just go on record here to say that the Johnson controller is indeed idiot-proof. It's been thoroughly tested by myself.

great thanks!!