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The other day my combined fridge/freezer stopped cooling. I tried to turn the temperature dials inside the fridge but it didn't work. I read that this could be due to the evaporator coils being frosted over, so I disconnected it for a whole day, with the doors open. When I reconnect it, the sides of the fridge get really warm (i guess thats where the condensers are?), and the freezer starts cooling (but the fridge stays warm). After two hours or so the freezer stops cooling, the sides are no longer warm, but the compressor gets quite warm and stays like that.

I have checked and the fans do work both in the fridge and the freezer.

I here are some pictures of the fridge and the compressor:

refrigerator compressor coolant line connections

Click for full size

More photos can be found here: http://imgur.com/a/gi7aH

I would appreciate it a lot if someone could help me understand what is going wrong, and how i could fix it.

PS: Sorry for the bad quality images. Also I should mention that above the compressor there was a tray that i removed to be able to take the pictures. I think its for collecting condensed water.

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+1 for including photos –  BMitch Jul 30 '13 at 13:33
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My guess is that your coolant may be running low. The lubricant for the compressor is contained in the coolant, and it may have a safety feature to turn off when overheating or when it's low on coolant. This wouldn't be user serviceable, and you'd want to find the cause of the leak (often a bad connection) and fix it so it doesn't reoccur. –  BMitch Jul 30 '13 at 13:41
    
My mini-fridge (4.2 cu ft) has a condensation issue and the coils freeze over, once I waited until it provided no cooling. It took 2 days to defrost enough to remove the rear panel and ~6hr with a space heater in it. After that I still had to clean out all the water so it wouldn't happen right after. Basically, defrosting for 1 day may not sufficient for a frozen solid larger unit. If you can manage it, I'd try defrosting for a few day before getting a service technician. If you have one, keep a fan running inside of it doors open. –  Jason Jul 30 '13 at 14:50
    
If the sides of the fridge are getting hotter than usual (condensor system) and you only have cooling in the freezer, you probably have a clogged capillary tube caused by some sort of breakdown in the compressor unit which is allowing only enough refrigerant through to marginally run the freezer. Replacement is probably indicated as compressor repairs and flushing are more expensive than the refrigerator. –  Fiasco Labs Jul 30 '13 at 15:17
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4 Answers

It sounds like there can only be 2 causes for the failure.

  1. The compressor is running inefficiently (normally caused by blow by or a bad winding on the compressor) - The only way to know of this is to hook a set of gauges up to the system to see the High and Low side pressures, and to check the resistance of the Run, Start, and Common windings of the compressor.

  2. There is a leak in the system (Normally very hard to find in fridges) The only way to know this is to hook up a set of gauges to the system. In order to find a leak in a fridge i would use an electronic leak tester as it can get into very confined spaces. The other way to find a leak would be to pressurize the system with nitrogen, and try to hear for leaks. If there is a very small leak you will have to go around with soap and water, or a type of refrigerant leak detector. The unit is more likely to leak on the high side of the system due to higher pressures and tempratures. This would be from the discharge of the compressor to the metering device, or the inlet of the evaporator. Other common places or leaks would be, the evaporator coil, or the condensing coil, along with any joints there may be in the system.

If the system just suffered a leak, and there is no damage to the compressor. If the leak is easily identified and repaired, the system can be recharged and repaired for a few hundred dollars. However this is normally not the case with leaks. If there is a small leak it can take hours to find and repair. Also if the leak is in the condenser or the evaporator, a replacement and the cost to replace it would normally cost about the price as a new fridge. The same goes for a compressor issue. If the compressor is running inefficiently, and must be replaces, the cost of the replacement compressor, the labor to replace it, and the refrigerant to recharge the system would also normally cost more then the price of a new fridge.

If you are going to have it repaired, have it done by an Appliance Repair Technician or a Refrigeration Technician.

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Sounds to me like your fridge has built in coils, which is the cause of the heat on the outside sides (condensing), and that your refrigerant is low, likely due to a leak.

To start with, you have to understand how it works to get the why. The refrigerant gas is compressed, passes through the outside coils (condenser) releasing heat and turning into a liquid. The compressed liquid goes through an expansion valve, reducing the pressure and extracting heat from inside (evaporator), turning back into a gas, where the process repeats. Your refrigerator is working (heat being released outside, heat being extracted/cooling slightly inside), but because of the low refrigerant, you have lower pressure which means a lower boiling point.

My opinion is that the compressor does more work trying to compress the gas, it is generating more heat outside, but less heat is extracted inside because the liquid changes back to a gas more quickly. I would recommend a worthwhile service person who should be able to add both refrigerant and a leak sealant -- knowing that it may not fix the problem depending on the leak and that you may need a refrigerator.

Reasoning: Research and having had it happen, and will be fixing my new kegerator soon (since we just went ahead and replaced the fridge).

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When you left the refrigerator unplugged, did you get a significant amount of water melting off the coils? If so, your defrost timer or defrost heating element may be bad. I have replaced the defrost heating element in my refrigerator; it's a hassle due to the tight space, but do-able for somebody with moderate electrical knowledge.

If you didn't get much water, you are likely looking at a refrigerant issue, causing the evaporator coils to not get cold enough.

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The start run relay on the compressor. It is a round disk that is shorted for a short time, long enough to apply voltage to the start windings for start up then goes to high resistance. The module can be opened up and the disk replaced from a module you picked up on garbage day from a fridge thrown out.

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