Fridge No longer cooling?

[Phishman068]

I have a GE dorm sized fridge that nicely fits 2 Cornies. When I found the fridge (literally) it had a nonfunctional thermostat system. I bypassed that and have it plugged into a STC-1000 system (The Ebay aquarium temp controllers). This made it work, and the system would maintain 3.3*C all day long. It did this for me for about a month, worked great.

Well now it's maintaining 5.5*C dispite being set to 3.3. The compressors been running nonstop for days, but 5.5*C Is as low as it will go. I've made sure the door is closed.

Any ideas?

 

[Hermit]

If it isn't frost free then it sounds like it is loosing freon or the compressor is inefficient. Neither is good. Do you have excessive frost built up?

 

[Phishman068]

I had excessive frost build up.
I shut it down for a few hours and scraped all that off. That seemed to help a little bit.

What might excessive frost build up represent?

 

[lumpher]

air getting in somehow

 

[Phishman068]

Air in the cooling system? Or just Air, in general. Atmospheric air entering the fridge?

 

[wyzazz]

Air entering the fridge. Check all the seals, look for cracks on the inside of the fridge. If it's the seal you may be able to get it to seal better by smearing vaseline around it.

 

[Hermit]

Either too much air is getting in or it is running too long due to a freon leak. You can tell the difference in a few ways. After defrosting, did the unit return to normal? Were any parts of the evaporator not frosted up as normal?

 

[Phishman068]

The evaporator was uniformly frosted.
After defrosting it appeared to be working better (Before it would only maintain about 8*C and now it will maintain 5*C.

I agree, it behaves as though the door is open or something, but really nothing has changed.

Any other tests I can do?

 

[Hermit]

If the evaporator was uniformly frosted then that rules out freon leak. Inefficient compressors are very rare. Do you have a fan underneath to blow air across the coils or are the coils mounted on the back? The fan may have stopped or the coils could be plugged with dirt. Those coils are like a dust magnet. Also, unscrew the light bulb. If it sticks on it can add a lot of heat. I haven't seen that in a long time, but it does happen.

I did a service call in a luxury booth for a news paper once. They complained that their mini-fridge wasn't working. It was so frosted up the door wouldn't close. I sat around drinking their beer and watching the circus set up. All I could do was leave the door open and let the ice soften up so I could get it out..... So......

 

[motobrewer]

the freon leak could have happened near the compressor - if that's the case, the fridge would still be uniformly cooled, right?

 

[Hermit]

the freon leak could have happened near the compressor - if that's the case, the fridge would still be uniformly cooled, right?

Doesn't matter where the leak occurs. It will affect the volume in the evaporator. If his evaporator is uniformly frosted, then it isn't a leak. A leak will cause a partial frost pattern that will continue to build up because the unit doesn't cycle off.