Troubleshooting Kegerator Problem (Won't get beer cold enough)

[mmacdon3]

So I've researched this topic quite a bit as it seems to be a common problem but I'd like to see if anyone can help troubleshoot this.
I was able to obtain a commercial built keggermeister fridge from a friend for free. The main problem is that I can't get the beer cold enough.

I've installed a computer fan on the inside that runs non stop and I've also plugged the fridge into my stc-1000 and set the temp to 38°, set the hysteresis to 1° and cooling delay to 3 min. I even did a light test for leaks and didn't see any light leakage. I think it's either a compressor problem or internal thermostat control problem.

The coldest I can get the beer is around 42°. The compressor doesn't run for long before shutting down and usually stays off for like 15-20 min before restarting. Shouldn't the stc-1000 force the compressor to run non stop till it hits the target temp? Its like there's an internal cooling delay that's still working. Also when the compressor starts up there some loud gurgling noises for a bit (low on coolant?). Also ice builds up on the cooling plate despite having an eva dry-500 in there.

I'm open to any suggestions. Compressor problem that isn't worth fixing? Or maybe I can do something to the internal temp controller to get it to run colder?

 

[eluterio]

Check the thermostat? I had a Edgestar kegorator and a freezer not getting cold enough. I finally broke down and had someone take a look at them. They recharged the coolant and both are not working 100%. You might have to get someone to come and test it. Its worth spending 100 bucks.

 

[mmacdon3]

Check the thermostat? I had a Edgestar kegorator and a freezer not getting cold enough. I finally broke down and had someone take a look at them. They recharged the coolant and both are not working 100%. You might have to get someone to come and test it. Its worth spending 100 bucks.

The internal thermostat is set to the max cold setting. What else should I check on it? I've heard of people making modifications to the thermostat but I wouldn't know where to start with that.

I just want to make sure I'm not overlooking some easy fix before I start to consider calling a repairman. Then I have to decided if its worth it to spend $100 on a repair or to just get a new fridge. The thing is this fridge is perfect because it's a pre built kegerator so no modifications were needed...I just updated the faucet and replaced the beer lines.

 

[Firewalker11]

Yes, freezing up is a classic sign of an under charged system. The gurgling noise at startup is not all that uncommon even for compressors that are working correctly with the right charge. It's likely not a compressor problem unless your compressor has overheated and has boiled the oil, that could cause the oil to become acidic and eat up the compressor. Probably not your problem.

I'm not sure how old your refrigerator is but it likely has a refrigerant called 134a, that is available off-the-shelf in 1 pound cans, you can get that from an auto parts place.

The problem is you probably don't have a way to braze on a Schrader valve so that you can fill it and test for pressure. That's where your local Refrigeration guys can help, they will have all the equipment and if the compressor is working, it'll be a five-minute job.

 

[mmacdon3]

Yes, freezing up is a classic sign of an under charged system. The gurgling noise at startup is not all that uncommon even for compressors that are working correctly with the right charge. It's likely not a compressor problem unless your compressor has overheated and has boiled the oil, that could cause the oil to become acidic and eat up the compressor. Probably not your problem.

I'm not sure how old your refrigerator is but it likely has a refrigerant called 134a, that is available off-the-shelf in 1 pound cans, you can get that from an auto parts place.

The problem is you probably don't have a way to braze on a Schrader valve so that you can fill it and test for pressure. That's where your local Refrigeration guys can help, they will have all the equipment and if the compressor is working, it'll be a five-minute job.

I'm not sure on the age of it as it was passed down to me...but it doesn't look too old. If it is indeed low on a charge doesn't that mean that there has to be a leak somewhere and that would need to be fixed as well?

 

[Firewalker11]

If the leak is in a tube, ez-pz, if its in the evaporator or condenser, he may just fill it up and call it a day. It made it this many years alright, a fill up will keep it going for sometime yet.

 

[user 4295]

You state that the compressor runs then shuts down before reaching setpoint, then restarts after 15-20 minutes. This sounds like the compressor is cycling on its internal, motor winding thermostats. These are bi-metal switches that are embedded in the windings of the motor in the compressor that protect it from over-heating. The compressor motor windings are cooled by the returning refrigerant gas, which is cold under normal conditions. If the system is short of refrigerant, the returning suction gas will not be cold enough to cool the windings, they will over-heat and the t-stats will open. The compressor will start again after the windings cool and the t-stats close.

If it's short of refrigerant, there is a leak. The leak may or may not be worth repairing, depending on where it's located. If it's a small leak in an impossible spot, a recharge may last a while. Problem is, most of these small systems are critically charged, meaning they have a capillary tube as a restriction and they require the EXACT amount of refrigerant (written on the product nameplate) in order to operate correctly. An ounce in either direction can effect performance significantly. The other problem with these small systems is that they rarely have access fittings to allow for testing pressures, recharging, etc. They do this to save money, but mostly because the amount of loss of refrigerant from just attaching the hoses and manifold gauges can effect a critically charged system. You also just can't top off the refrigerant in a critically charged system, because you don't know how much is remaining in the system. You really need to recover what's in the system, utilizing temporary copper piercing valves, remove piercing valves and braze in permanent service valves, pressurize with nitrogen to leak check, blow off the nitrogen, repair any leaks (if possible), leak test again, connect a vacuum pump to pull down into a deep vacuum, then weigh in the exact refrigerant charge stamped on the nameplate. You can see how this can add up quickly.

 

[william_shakes_beer]

so it's going to cost $$$ to find out if it can be repaired, and may still require replacement? So That's why there are so many friges in the landfill

 

[mmacdon3]

Thanks for the great information everyone. I'm going to continue to drink my 42° beer while debating what my next move should be. I'm going to price out getting it repaired and also price out just getting a new fridge.

If I do decide to get a new one I'll probably try bypassing the internal thermostat first just in case that solves the problem.

 

[Firewalker11]

Thanks for the great information everyone. I'm going to continue to drink my 42° beer while debating what my next move should be. I'm going to price out getting it repaired and also price out just getting a new fridge.

If I do decide to get a new one I'll probably try bypassing the internal thermostat first just in case that solves the problem.

Sorry, you cant, it's internal.

The above description is correct about all the critical stuff but there is a tube that can be pierced to evacuate the system, add the right amount of refrigerant back in and seal it back up. If you lived by me, Id fix it for you for some beer, find a guy with a refrigeration background and make a trade.