Johnson Controls Refrigerator Thermostat

SKU: 7051

External overriding thermostat with analog control and preset differential.

Availability: In stock


Johnson Controls Refrigerator Thermostat


Lager year round with this external overriding thermostat. It installs on a fridge or freezer to maintain optimal fermentation temperature—trying to lager in a fridge without an external overriding thermostat results in temperatures that are too cold for yeast or even in frozen beer. Plug the appliance of your choice into the thermostat, then plug the thermostat into a standard 120V outlet. An analog dial lets you set the setpoint temperature between 30 and 80°F, with 1 degree increments. The Johnson Control thermostat has a 3 1/2 degree differential, which means that the thermostat will shut the fridge or freezer off (stop cooling) at 3 1/2 deg below the setpoint and start the unit (resume cooling) once internal air temperature exceeds the setpoint—the effect of this fluctuation on the actual temperature of fermeting wort or beer will be insignificant.

Additional Information

Support Documents: No

Customer Reviews

Works as advertised Review by David
Easy set up, keeps the beer at fermentation temps no problem. Saves me money over the digital one, which of course equals more money for brewing beer! (Posted on 10/14/13)
Works like it should! Review by Jarrod
Been using this product for over a year with ales and lagers. (approx. 10+ batches) It works very well! Mine has a swing in air temp of 7-8 degrees which means that the target temp for fermentation is within 1 degree F. That is VERY consistent and will not affect the beer. This is a great product and I highly recommend it. (Posted on 8/19/13)
ok unit but get the digital one Review by helles
It works, I have two, but one just became so rusty and corroded after 1.5 years, it just stopped working. (Posted on 7/8/13)
Started off strong. Review by Charles
This product started off doing everything it says in the description but now after just over a year of using this product it is swinging at least 10 degrees if not more. I had it set at 64 and found it at 58 then checked later that day and found it at 70. It seems to be running more on the cold side, I see it in the high 50's or at 60 more than above so my fermentation is at a crawl. I raised the temp to 68 to see if it is just a little our of calibration and now it is at 70 more than anything when I check it. At least my beer has some small krausen on it. If I could go back in time I would spend the extra money and upgrade to the digital. Hopefully it lasts longer than this one. (Posted on 7/7/13)
Good but not Great. Review by Redfields2
I've been using this unit with a chest cooler for 3 years with good results. While somewhat tricky to set the temp because the scale on the unit doesn't match how cold it actually keeps the cooler once it is calibrated it does pretty well. Temp swing about 10 degrees but because of beer the temp variation is not important. If I had it to do over I would have spent the extra few dollars to by the digital unit.
(Posted on 3/9/12)
fair unit but short life span Review by mick
Bought this 16 months ago and it has just now decided to stop working. Now my keezer is subject to the temperature of the garage. (Posted on 3/8/12)
Has worked for years Review by Rob
Mine has worked for years w/o a problem. Other reviewers have correctly commented that the temperature swings in the air are much greater than the swings in the beer temp because of the huge difference in thermal mass. One way to reduce the air temperature swings (if you are using a conventional fridge) is to put a couple water-filled milk cartons in the freezer section to increase the thermal mass in the section where the cooling is taking place. I am sure the digital version is a fine product but I wonder if it uses digital filtering to smooth out the temperature swings on the display. Thermodynamics obey the same laws of physics whether the controller is digital or analog, so as long as the fridge motor is cycling at the same rate, your beer temp history will be the same. (Posted on 12/14/11)
understanding how this works Review by jon
The way any thermostat or temperature controller works, you are going to see some temperature fluctuation. otherwise the compressor on the fridge/freezer would be cycling on and off too much and wear out prematurely. not good.

you have to remember as a few others have pointed out, the liquids (beer) in your fridge will change temperature much less rapidly than the air around it. so the air temperature fluctuations are actually normal, and beneficial. on some temperature controllers, you can adjust the spread between where the unit stops and starts cooling again, but like I said, you make this spread too small, and you will not have any better cooling of your beer, and your fridge will wear out faster.

Get one of these, relax, and have a homebrew... from a keg! (Posted on 11/29/11)
It really does work. Review by Mike
I have to agree with danmdevries. I've used mine for a year now. I keep one thermometer checking the air temp and another one in a regular 12 ounce beer bottle full of water.
The air temp will fluctuate about 10 degrees, but I've never seen the water (even though it's only 12 ounces) off by more than 1 degree of my target. Even when lagering.
I just got a second chest freezer and I'm going to keep the first as a fermenter chest. I need another thermostat and I'll be buying another one of these. (Posted on 11/25/11)
Great Controller Review by danmdevries
Reading these reviews I thought I'd add my two cents.

I've been using it on a converted freezer/keg cooler. Zero issues.

Temps do swing quite a bit in either direction when measuring ambient temp inside the freezer. This is the common complaint I'm reading here in the reviews.

Remember this unit is an analog unit. The temp probe is a volatile fluid filled capsule with capillary tubing to a mechanical switch. It takes time for fluid to respond/acclimate to ambient temp changes. Therefore the thermostat will allow for fairly significant ambient changes in temperature.

However, measure the temp of your fermenting product. It will be held at a steady temp. Unless you're fermenting in 0.5 oz containers, the temp probe will respond to the temp change faster than the fermenting product will change its temperature.

I've seen 12-20 deg F fluctuations in ambient cooler temp. Keg temp actual has been well maintained within 1*F for well over a year.

It takes a long long time for 5-15g of beer to change temp just like it takes a long time to change temp in the fluid reservoir/capillary tubing of the temp controller. Difference is the temp controller has maybe 0.5mL of volatile fluid designed to respond rapidly to temp changes. Your beer does not. It takes its sweet time (for me, 8-10deg in 12h is avg). Keep this in mind before complaining about temperature variations in a mechanical controller.

(Posted on 11/16/11)
Don't waste your money Review by No Good
I hooked up one of these to my fridge, and I'm getting temperature swings of 14 degrees. I even brought it in from the garage, and into the house- still 14 degree swings. I'm throwing this one out (I can't find my receipt to return it). Hopefully the digital version works better. I feel like this was a complete waste of money. I'd give it an "empty glass" if there were an option lower than "1 pint". It does seem to be sturdy, for whatever that is worth. If you're okay with brewing beer with all kinds of off notes, this might be the controller for you- although I'd bet you could control the temperature better with a lamp timer. (Posted on 9/28/11)
Works.... sort of... Review by Daniel D
With this unit set at 32, the temperature fluctuates between 34 and 42. Once I have opened the converted freezer to find frost on the side, so I turned it back up to 36. When I opened the freezer a few days later, it was 46! I'm using the freezer to keep beer cold for force carbonation, so it isn't a big deal. But still, I would not buy another one. (Posted on 9/21/11)
Not what I thought it was Review by Chulsky
I bought this controller from a local homebrew store and I did not realize that it was a cooling only control. I have a fermenter heater but this will not work with it. I wish I would have saved the $$$ and bought the digital one. (Posted on 3/14/11)
Keeps beer from freezing. Review by brainfrz
I picked this up at another store but figured a review was in order. Temp is a bit off from the dial to what is true in the freezer, which seems to be the common complaint about this device. I've got a wireless thermometer in the freezer so I can see what the temp is without opening it- have controller set to 32 and freezer is at 41. Not a big deal though. (Posted on 3/4/11)
A controller, NOT a thermostat. Review by erik
Just be warned that this is NOT a thermostat replacement, it is a temperature controller. It works by controlling the flow of electricity to your compressor and assumes that the thermostat on your refrigerator can be set to the lowest possible setting. (Posted on 10/17/10)
Works fine for me Review by Hercules Rockefeller
I've been very happy with this temperature controller so far. It seems to keep the fridge a few degrees warmer than I've got it set to (per my digital thermometer but not verified with a second thermometer), but I haven't calibrated it per the enclosed instructions. For my purposes (using a freezer for a beer fridge), that's fine. I simply set it to 33F an I've got roughly 36-37f beer. If I needed to lager I'd probably bother to calibrate it. The air temp of the fridge does fluctuate by about 6 degrees or so, but that's fine. The air temp is going to fluctuate much more than the temp of the beer or wort, and my beer is always plenty cold. (Posted on 10/11/10)
It is ok BUT! Review by Sheep MT
After a few times the temp is not steady. I have to turn the dial to less than 50f for 62f. Then the temp goes up and down as much as 6 degrees. It is still better than nothing. (Posted on 8/28/10)
It will do in a pinch!! Review by mimsey11
This controller is okay, I definitely think the digital controller is a better purchase!! (Posted on 7/5/10)

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