Guide to set internal chest freezer thermostat to >32F; Eliminate external control

For those who have tried this and find that their compressor is cycling too frequently:

These electromechanical thermostats have a built-in hysteresis (temperature above the set point at which the compressor will cycle on vs temperature below the set point where it will then turn off). The hysteresis is what prevents the compressor from rapid cycling, which causes premature failure. Unfortunately with these electromechanical thermostats the amount of hysteresis is related to the set point of the thermostat in such a way that as set point temperature is increased hysteresis is decreased. The exact amount is dependent upon the individual thermostat design and to a lesser extent unit-to-unit variability. Hysteresis can usually be adjusted by disassembling the thermostat and bending a leaf spring, but doing so is beyond the typical DIYer.

Thus my recommendation is if you are running into rapid cycling by trying this technique I suggest you return the factory thermostat to its original setting and invest in an external controller.

AssistantBrewer

AssistantBrewer said:

For those who have tried this and find that their compressor is cycling too frequently:

These electromechanical thermostats have a built-in hysteresis (temperature above the set point at which the compressor will cycle on vs temperature below the set point where it will then turn off). The hysteresis is what prevents the compressor from rapid cycling, which causes premature failure. Unfortunately with these electromechanical thermostats the amount of hysteresis is related to the set point of the thermostat in such a way that as set point temperature is increased hysteresis is decreased. The exact amount is dependent upon the individual thermostat design and to a lesser extent unit-to-unit variability. Hysteresis can usually be adjusted by disassembling the thermostat and bending a leaf spring, but doing so is beyond the typical DIYer.

Thus my recommendation is if you are running into rapid cycling by trying this technique I suggest you return the factory thermostat to its original setting and invest in an external controller.

AssistantBrewer

Click to expand...

What would you suggest in my case, where the compressor cycles pretty regularly to keep temps, but the relay (or other switch) keeps clicking on between compressor cycles?

Is this a result of the compressor trying to turn on and the relay preventing it based on a time limit for safe compressor cycles? If so, can this relay eventually wear out?

I've been trying to get my freezer set up properly and am having a hard time even figuring out which direction I should be turning the dang screw. All the posts I've seen on screw direction say they are turning clockwise or to the right. Has anyone that's done this had to turn the screw counter clockwise?

Also, anyone done this with a frigidaire model, how did you turn the screw?

gsector said:

I've been trying to get my freezer set up properly and am having a hard time even figuring out which direction I should be turning the dang screw. All the posts I've seen on screw direction say they are turning clockwise or to the right. Has anyone that's done this had to turn the screw counter clockwise?

Also, anyone done this with a frigidaire model, how did you turn the screw?

Click to expand...

I have a Frigidaire...I turned it about 8-10 cranks clockwise

This worked like a dream on my Magic Chef. 12.5 turns in and im sitting at a balmy 38 degrees. Thanks for this walk-thru it saved me $60

could the relays clicking have something to do with the frost free cycle on the newer units

Agentaaron said:

I have a Frigidaire...I turned it about 8-10 cranks clockwise

Click to expand...

Thanks, I think I've got it now. I turned it too far counterclockwise and the spring came off, put it back on and the temperature is getting close.

I was excited to find this thread a week or so ago as I'm currently building a keezer from the Frigidaire FFC0723GB. For the past week I have been trying to set the thermostat but I can't seem to get it right. The temperature swings too wildly.

I have a digital thermometer's probe sitting in a container of water in the freezer. There is also a case of bottled water, a corny of beer, and a CO2 tank in there to create some thermal intertia. I had the thermostat dialed in to where the compressor shut off at 39F. But the compressor never came back on and the internal temp got to 58F. So I backed the thermostat screw off just 1/8th of a turn to lower the setting a wee bit. The compressor came on and took the internal temp down to 30F. After it shut off, it rose to 36F and then the compressor came back on.

It seems to me that the internal thermostat in this model freezer is too finicky and has too wide of a thermal swing range (or whatever you call it) to be trusted. Unfortunately, I think I am going to have to put an external controller on the unit.

That's exactly what I'm seeing. I can get it to hold steady at just barely above freezing, but any adjustment past that and it shoots up into the upper 50's. I just can't get it to sit around 40.

Can anyone tell me which direction clockwise or cc raises the temperature setting on the frigidaire freezers?

On mine, clockwise (tighten) raises the temperature, counter-clockwise (loosen) lowers the temperature. Seems backwards, but that's how it is.

carrolte said:

Can anyone tell me which direction clockwise or cc raises the temperature setting on the frigidaire freezers?

Click to expand...

Clockwise=warmer
Counter clockwise=cooler

thanks guys!

ChshreCat said:

That's exactly what I'm seeing. I can get it to hold steady at just barely above freezing, but any adjustment past that and it shoots up into the upper 50's. I just can't get it to sit around 40.

Click to expand...

Same here. I finally gave up after nearly a month and a half of adjusting. Seems like this is happening to a lot of us with Frigidaires.

Gimlet said:

Same here. I finally gave up after nearly a month and a half of adjusting. Seems like this is happening to a lot of us with Frigidaires.

Click to expand...

My Frigidaire seems to be holding just perfect at 38*. My issue is that the compressor kicks on about every 3-5 minutes and runs for about 30 seconds to hold temp. I am going to set mine back and get an external controller asap. I don't wanna burn out my compressor...

What an awesome thread! I popped open my Frigidaire this morning and now I'm stumped. I don't think this one has an adjustment screw...what do you guys think?

I've been looking at the damn thing all morning and I'm stumped (not that that's very difficult ). Thanks in advance!

NYC said:

What an awesome thread! I popped open my Frigidaire this morning and now I'm stumped. I don't think this one has an adjustment screw...what do you guys think?

I've been looking at the damn thing all morning and I'm stumped (not that that's very difficult ). Thanks in advance!

Click to expand...

Remove the controller from the mounting point. They're must be a adjustment screw.

-= Jason =-

If it's like mine, the adjustment screw is facing down in that picture.

I had a fridge with a deadband of over 12c so I had to put an external controller on it, that said it didn't last very long before it gave up as lagering pushed it a bit too far. I use a freezer now and it's a lot better, ATC-800+ all the way.

NYC said:

What an awesome thread! I popped open my Frigidaire this morning and now I'm stumped. I don't think this one has an adjustment screw...what do you guys think?

I've been looking at the damn thing all morning and I'm stumped (not that that's very difficult ). Thanks in advance!

Click to expand...

Like ChshreCat said, your screw is facing toward the floor in the pic you posted. So you need to mount the cover back onto the keezer and remove the stock fine adjustment knob. The set screw is under that.

Mine had a piece of tape covering it once I got the knob pulled off.

I have been using a simple light timer for temp control with pretty good luck.The timer i have is not ideal ,because it has to go on for a 1 1/2 hour block of time minimum. It keeps cornys at about 45 if it runs twice a day.Now that ive seen this thread I might try adjusting the thermostat.

You guys were absolutely right, the screw was right where you said it would be. See attached pics, one with tape one with it exposed. I could have read the very first post in this thread a little more closely and would have seen the same thing!

So I have a Frigidaire. Turned it 2 or so turns to counterclockwise = 24F after 24 hrs: frozen beer. Turned it another 3 or so turns = 27F after another 24 hrs: frozen beer. I'll keep trying!

Thanks again, I hope this works so I don't have to wire up the one I recently purchased.

Just did this to my 7.2 CF magic chef freezer. Turned the coarse screw CW until tight just like Flomaster and set my dial on the front to 1. Keezer has been sitting at 38-40 for the past 24 hours.

subscribed

NYC said:

You guys were absolutely right, the screw was right where you said it would be. See attached pics, one with tape one with it exposed. I could have read the very first post in this thread a little more closely and would have seen the same thing!

So I have a Frigidaire. Turned it 2 or so turns to counterclockwise = 24F after 24 hrs: frozen beer. Turned it another 3 or so turns = 27F after another 24 hrs: frozen beer. I'll keep trying!

Thanks again, I hope this works so I don't have to wire up the one I recently purchased.

Click to expand...

haha...Warning, don't test this adjustment with kegs of beer in your chest freezer! lol

I think I made the same mistake though.

I have a little crappy 5cu ft frigidaire that I did this on about a month ago. I can actually get it up into the high 50's (possibly higher, but I haven't needed to go any higher) and still get down under freezing. So, it's served me both as a keezer and as a lagering chamber already.

Subscribed. Has anyone tried this/had any success with a Haier? I just got the 7.1 cuft yesterday and it would be great not to have to order another aquarium temp controller for it.

A slight update on my Frigidaire (I'll look up the model if anyone is interested), I've probably gone 10 turns CCW and it's still freezing the beer...oh well!

I believe that I went clockwise on my Frigidaire.

diabolicaldon, do you know your model number? Mine is 297010501F, I think I read a few pages up that I should be turning CCW but it's worth a shot.

I turned the keezer on and turned it all the way CW. It felt like I was tightening it, but in either case I'll have cold brew for a few hours tonight ...then maybe frozen beer!

Just got a Maytag 14.8 freezer (model MQC1552TEW) from Home Depot. Fits 9 ball locks on the floor and a 5# bottle on the corner compressor hump. The thermostat is on the right side of the unit and is super easy to access (two small screws). Once the thermostat unit is out, pop off the plastic knob and just use some pliers to slightly loosen (1/8th turn) the silver nut holding it in place in the plastic housing to get the actual thermostat unit free. The small screw is on the top of the unit (opposite end of the two plugs shown in the picture). It took me 12 turns clockwise to basically dial it into a 40 degree setting with the big knob set between 4 and 5. I might fine tune further, but this is good for now.

Thanks so much to the OP. You just saved me some serious loot. Vote for sticky on this one!

NYC said:

diabolicaldon, do you know your model number? Mine is 297010501F, I think I read a few pages up that I should be turning CCW but it's worth a shot.

I turned the keezer on and turned it all the way CW. It felt like I was tightening it, but in either case I'll have cold brew for a few hours tonight ...then maybe frozen beer!

Click to expand...

How did turning it CW work out for you?

I'm at work right now, so I can check the model when I get home.

Thank You OP! (And everyone else)

Got the same freezer as mmonacel, am currently chilling it down- Thanks for saving me the cash OP!

D_Ranged_Eskimo said:

Subscribed. Has anyone tried this/had any success with a Haier? I just got the 7.1 cuft yesterday and it would be great not to have to order another aquarium temp controller for it.

Click to expand...

I just purchased the same freezer from Costco, so I'd like to know the answer to this question as well. Anybody have pointers for the 7.1 cu ft haier?

Update: for the Maytag 14.8 in post 192, I have turned it 20 times clockwise which appears to be the limit for the screw. This has been holding 51-53 degrees for me at the 5 1/2 position on the big dial which is perfect for what I'm looking for. Just some extra info for those interested.

Stumbled onto this post while searching for keezer ideas. Fantastic. I just bought a 7.0 cubic foot freezer from Menards for $189, and the thermostat was exactly like the one pictured in post #4.

Just remove the side cover, then there's a white plastic cover behind the front temp control panel. Two screws remove that, then the panel will pop out the front to expose the set screw. I turned it clockwise probably 10 full turns and plugged it in. I left it over night and it was reading 30F air temperature (while empty) this morning. I put a gallon of water in there just to see if it would freeze, but it's certainly looking good for me.

Just be careful because once the side cover is removed there are lots of wires/tubes all over. Removing the two internal screws takes a little finesse, but not tough. The whole thing took me less than 10 minutes.

Update: ended up adjusting all the way until the screw stopped, then setting the knob to 1. Seems to have settled on about 35F liquid temp in a gallon of water I have in there.

So I tried this last night on the 7 cu ft freezer I bought from the home depot. max temperature seems to be hovering around 33F, but I think my digital thermometer is reading off. there is ice in the 1 liter glass that I filled with water and placed in there to have some extra thermal mass for the temperature readings.

I did notice the cam on the temperature knob gets wider in diameter as you turn up the temperature. it gets really steep right as you are turning it off in the space between 1 and off. there are about 4 dots marking there. I had initially tried to set it to one of the dots, but the slope of the cam is so steep it is hard to set accurately and the smallest movement throws it off by upwards of 20 degrees.

my plan is to make a couple of small shims to place on the arm that rubs on the cam. this arm, when pulled away from the center of the cam controls the temperature. I figure if I can slip about a 1/8" think piece of metal in there and superglue it in place I will have a pretty permanent fix. and I can probably set the coarse adjustment screw back a little closer to normal in order to keep the deadband from being to narrow and running the compressor too much.

Got the kenmore 8.8 home last night, and have been contemplating my build and happened upon this post!

Turned the screw CW til up stopped moved the fine adj knob to 5 and its dialing in around 38 right now! A few more hours of tweaking and itll be perfect!

thanks!!!

Anyone know if this works with the GE 7.0 from Home Depot? Everything I see in this thread regarding this freezer seems to point that it can't get warm enough turning the screw all the way in clockwise.