Keezer running almost 24/7 and compressor very hot

[Undead8]

Is my freezer dead or am I doing something horribly wrong?

I converted a chest freezer by pluging in a STC-1000. The STC works as intended and will turn my freezer on and off at the correct temperature. I also screwed a draft tower on top of the freezer, with a hole big enough so that the 3 beer lines will go throught.

My problem: The compressor will run almost constantly. Most of the time, the temperature inside will not drop below 40F. Because of this, the compressor gets really hot (I can touch it, but can't keep my hand on it for more than 15 seconds). There is also some ice buildup inside on the side of the freezer, near where the lid is.

Sometimes, I will unplug the freezer for a few hours to let the compressor cool, then plug it back in. On the next first cycle the temperature might drop to the turn off point. But on the second cycle, it will most likely stay above 40F and run non-stop.

I noticed that if the freezer is unplugged for 2 hours, the temperature will go from 39F to 46F approximately.

My STC-1000 setup: Turn off the compressor at 37.5F, turn back in at 40F. Has a 10 minutes compressor delay (meaning that it will wait 10 minutes after it reaches 40F before turning it back in).

Can anyone help me?

 

[Thanks_Yeasties]

Where is your temp probe in the keezer?
Is it in a liquid?
Do you use a fan to move the air around in the keezer?
Do you notice a large difference in temp between the top of the keezer and the air in the bottom?

 

[wmubronco]

You can help with airflow on the coils of the compressor with a small desk fan, and the airflow inside the keezer with a computer fan.

I also would check the calibration of your temp probe, i.e. used crushed ice water to mimic the 32degrees temp for about 5 minutes to ensure you're getting the correct readings.

 

[day_trippr]

What's the history of the freezer?
When was the last time it worked - properly - as a freezer?

Cheers!

 

[raouliii]

[.... Has a 10 minutes compressor delay (meaning that it will wait 10 minutes after it reaches 40F before turning it back in)...(

I agree with the previous post's comments and questions.
In addition, have you wrapped it with any additional cabinetry or made any other modifications? The condensor coils MUST have the ability to release heat, through the exterior skin of the freezer, if it doesn't have external coils. If the condensor coils are not heating up, the compressor valves may be worn out and leaking.

BTW, the compressor delay timer starts counting when the previous ON cycle ends, not when the current ON cycle begins.

Are you certain that you have a fahrenheit version of the STC1000 or is it a different model #?

 

[iijakii]

Is the dial set to the coldest setting? What's the condensation situation like on the inside? I bet you have some serious seal problems.

 

[slym2none]

I bet you have some serious seal problems.

 

[renrutle]

While seals are @ss4ole5

Does/did the freezer run properly prior to the installation of the STC-1000? If you are getting ice on the inside of the freezer the compressor is cooling but the STC temp probe may be connected or placed incorrectly or the STC is not working properly or is not programmed correctly.

I would

• Disconnect the STC and verify that the freezer is working properly.
• Set the Freezer thermostat to the coldest setting and test without the STC
• Verify temp with another thermometer
• Verify the STC programming- did you hit the "set" button after selecting temp, etc.
• Verify the STC probe wiring
• Place the probe in the freezer in a container of water.
• Verify the STC settings by testing at 50deg F
• Place another thermometer next to the STC probe to verify termperature

Obligatory

Start from no STC configuration and work up to rule out issues until problem is isolated.

 

[Undead8]

Thanks everyone. Here are the answer to your questions.


Where is your temp probe in the keezer? I wrapped the wire around a beer line. The probe is standing in the air in the middle (height) of the freezer.
Is it in a liquid? No, should it be?
Do you use a fan to move the air around in the keezer? No.
Do you notice a large difference in temp between the top of the keezer and the air in the bottom? Not really.
I also would check the calibration of your temp probe, i.e. used crushed ice water to mimic the 32degrees temp for about 5 minutes to ensure you're getting the correct readings. Just did it and it dropped to 0,5 celsius as expected.
What's the history of the freezer? When was the last time it worked - properly - as a freezer? I never used it as a freezer. I bought it used and converted with the STC-1000 right away. At first, the STC only had a 0,5Celsius differential and 1 minute compressor delay, but it worked really fine for many months (6 maybe). Then, I screwed the beer tower on top of the lid and left it unplug for a week or 2. Shortly after that, after a very hot day if my memory is correct, it started running constantly. I changed the settings of the STC-1000, did some unplug/plug cycle of a few hours during a few days. I got it to work again for a few months, then it started to run constantly again a few weeks ago. Doing the plug/unplug thing doesn't seem to work anymore.
BTW, the compressor delay timer starts counting when the previous ON cycle ends, not when the current ON cycle begins. Are you certain that you have a fahrenheit version of the STC1000 or is it a different model #? I have a celsius version and converted the temperature for you in my first post!
Is the dial set to the coldest setting? What's the condensation situation like on the inside? I bet you have some serious seal problems. Yes, it's on the coldest settings, but I'm pretty sure the way I installed my STC-1000 bypasses the freezer dial set (I installed the STC inside the freezer using the freezer wires - yes, it works correctly). I'm not sure what you mean by condensation. There is snow/ice buildup on the side of the freezer near the top close to the lid. Is it what you mean? And what is a seal problem?

Thanks everyone for your help.

 

[Undead8]

Is the dial set to the coldest setting? What's the condensation situation like on the inside? I bet you have some serious seal problems.

I've been thinking about seal problems. The condensation I have appears in less than 24 hours and it's always on the same side of the freezer, near where the lid opens on the far right. I just happen to have a beer line a bit in the way there. The lid seems to close just fine, but if condensation builds up there, I must have air coming in form the outside!

I'll try moving the keg around so there's a tight seal and see if there's condensation tomorrow.

If that's the problem, I'll go hide in a closet and never post again on this forum under this account name.

 

[beersk]

Is the dial set to the coldest setting? What's the condensation situation like on the inside? I bet you have some serious seal problems.

It should be set to the warmest setting, should it not? If it were a refrigerator you'd want it set to its coldest setting, but a freezer, I think, should be on the warmest setting.


That seals post was hilarious! @slym2none

 

[renrutle]

I'll go hide in a closet and never post again on this forum under this account name.

Don't be scurred!

We all learn from ourselves and others!

Maybe you are here to teach the rest of us how not to do it.

 

[day_trippr]

Frost buildup in one corner of a chest freezer is a common citation right before the Death Certificate is issued...

 

[djonesax]

If its a chest freezer, I can see the frost issue being an issue with the seals. But the leak would have to be pretty big for it not to get below 40 since cold air sinks. It sounds like you have three potential issues. 1. A huge air leak. 2. Low on refrigerant. 3. Condenser coil not able to cool down. The compressor will get hot but if it gets too hot there is typically a thermal switch that will shut it off to protect itself. If its not shutting off then it might be normal.

I would disconnect the STC-1000, put something heavy on the lid and see if it freezes water. If it freezes than its either low on refrigerant or the condenser is not able to cool, possibly because you have covered the outside of the freezer? In either case a new previously owned freezer might be a good idea.

David

 

[Takuie]

Don't be scurred!

We all learn from ourselves and others!

Maybe you are here to teach the rest of us how not to do it.

Don't sweat it, everything happens for a reason.

 

[Stealthcruiser]

Tape your probe to a larger thermal mass, ( keg?), and insulate it from the air mass.

If my keezer begins to cycle too much, or run too long,I check the keg that the probe is taped to, ( for quantity, re: thermal mass), and move it to another as needed.

I also keep an unused keg in the keezer, filled with a water / StarSan mixture, that I can move the probe to as need / if needed.

All of my kegs have a piece of closed cell polyurethane foam taped to them with "speed tape", and the foam has a 1/4 channel on the keg side, where the probe slides in..........Tightly.

Unless you know the probe is waterproof, don't submerge it.

 

[jbb3]

Did you ever say where you have the keezer siting? Is it in a conditioned or unconditioned space?

If it's sitting somewhere in 90 degree + ambient temp, the compressor will struggle to overcome the extreme temp differential.

Add to that; a little low on freon, a leaky seal and a tower that's acting like a heat sink, you'll have a compressor that runs constantly trying to get down to temp.

If it is due to sitting in a hot/unconditioned space, a small fan aimed at the compressor will help some. But you really need to move it to a cooler location.

Either that, or maybe it's time to start searching CL again...

Also, once you get it operating properly again and as others have said, keeping the temp probe in some liquid will help reduce temp swings. I use a plastic half gallon milk container about 3/4 full of water. Just don't let it sit directly on the bottom of the keezer. It will give to a false low reading.

And if you added a tower, you'll need a fan to circulate the cool air up into the tower. Otherwise, you're first pour or two of the day will be pretty foamy. Shoot for a temperature differential between the keezer and the tower to be less than 10 degrees.

Hope that helps...

Cheers!

 

[Undead8]

Wow there's a lot of good advice here!

Just so you know, I moved the keg around so the beer line would not be in the way of the lid. There's no more ice buildup and the compressor is off most of the time. So it does seem I had a seal problem because of a beer line.

 

[MannyEdwards]

If it's low on refrigerant, it will behave like this. You might try recharging it. Ice on the inside is normal during the cooling cycle, depending on how much humidity is getting in there.

 

[Gavin C]

Sure sounds like your freezer is giving you it's death rattle.

Probe placement for a keezer should not be on a keg. This is too great of a thermal mass. Kegs less full will get much warmer/cooler than the measured full keg. Similarly as the keg empties its efficacy as a heat sink reduces.

Don't measure air temperature as this is subject to greater swings and compressor cycling and subsequent freezer death. (cue the dramatic music of your choice)

Measure ambient but with a small heat sink that will remain clean and relatively stable. A small jar of inert powder. I use baking soda in a 4 oz baby's bottle. Bury that probe in there and place it toward the bottom of the freezer as that is where your beer will be dispensed from if there is any stratification.

Reduce/eliminate stratification with a fan. Doesn't take much power to do that effectively.

Button up any leaks/suspected leaks.

Cross your fingers your freezer will pull through. I have my doubts but I'm a terrible pessimist. Hope I'm wrong and it makes a full recovery.

 

[day_trippr]

Probe placement for a keeper should not be on a keg. This is too great of a thermal mass. Kegs less full will get much warmer/cooler than the measured full keg. Similarly as the keg empties its efficacy as a heat sink reduces.[...]

otoh, I've had a 7 keg keezer for going on 9 years and haven't found any negative to controlling the compressor with keg temperature.

The only thing even worth mentioning is to make sure the probe is well below the "beer line" on the measured keg, and is both well-coupled to the keg wall and well-isolated from the keezer air temperature.

I move the key probe to the fullest keg once the current one has dropped below the one-third-full level - it's pretty obvious when this needs to happen as I have a five channel temperature logger watching over my keezer's vitals and can see the compressor cycle time dropping. Otherwise it's pretty effective afaict.

My keezer never runs higher than a 20% duty cycle even during the doggie days of New England Summer. On for an hour, off for four or more, year 'round, the compressor totally loafing along through life. I like it like that...

Cheers!

 

[Gavin C]

I would defer to your expertise on this topic @day_trippr . I've seen your keezer wiring and controls another posts and am in something of awe at the detail you have gone into.

My little heat sink in my non-pimped out keezer with picnic taps requires no adjustment.

OP listen to @day_trippr .

 

[Jwin]

To check the seals, get a lantern/maglite, and drop it in the keezer at night and then just look for light escaping.

 

[MindenMan]

I think I missed something here... in post #18 the OP says he figured out the problem, or did I read that post incorrectly?

 

[day_trippr]

I think I missed something here... in post #18 the OP says he figured out the problem, or did I read that post incorrectly?

No, I believe you have that correct.

We've apparently moved on...

Cheers! ("Thread Drift: It Happens" )

 

[Gavin C]

Sorry about that. Drifting with the best of them. Glad to reread (correctly this time) that the issue was resolved. #Glad_to_be_wrong .

Edit: At least i got to see that great seal picture by @slym2none . Great chuckle there. Thanks mate.

 

[day_trippr]

I would defer to your expertise on this topic @day_trippr . I've seen your keezer wiring and controls another posts and am in something of awe at the detail you have gone into.

My little heat sink in my non-pimped out keezer with picnic taps requires no adjustment.

OP listen to @day_trippr .

At the end of the day, once a keezer or kegerator achieves the "goal" temperature, pretty much any technique should provide the same duty cycle, as a given keezer with whatever thermal mass therein will warm up at whatever rate no matter how it is controlled

The differences will be found in the compressor cycle times. I'm operating at the opposite end from what one would get with a probe hanging in the air inside the keezer. I can allow for a two degree F beer temp range while maximizing the compressor cycle time - the metric I'm most concerned with when it comes to longevity.

No doubt there are other ways to achieve similar results...

Cheers!

 

[Undead8]

Well, the problem WAS resolved, but the compressor just started running again 24/7.

I put a flashlight inside the freezer, but did not see any light coming out from the seal. However, when I put a 5$ bill under the seal (door closed), there is absolutely no resistance when I pull it out, almost everywhere around the door. So I still think I have a seal problem. Also, the seal is a bit cracked.

I ordered a new seal and will replace it. I hope it will fix it. Meanwhile, I'll turn off my freezer so I don't kill it.

Now, I worry that I'll lose my beer and/or that I already damaged the compressor by letting it run all the time... I also found a patch of duct tape under the freezer. I hope the freezer was not pierced and let some coolant out before the previous owner 'cleverly' patched it. We'll see!

 

[raouliii]

Rest assured, duct tape can not patch a refrigerant line.

 

[gnef]

Just to give another data point, whenever I have had a chest freezer or now a window AC unit that runs constantly and can only cool to a certain temperature, it was dead, and needed to be replaced.

I always try the unplug and rest option first, but it has never helped me, at least. I hope you can figure it out, but I think you will ultimately have to replace the freezer.