My Refrigerator Thermostat Doesn't Shut Off

Thermostat

• Refrigerators have a thermostat inside the cooling area that allows you to adjust the temperature as you see fit. Though a simple mechanism, it is quite possible for a sensor inside it to fail. Either a faulty defrost control or fresh food thermostat could be what is keeping the compressor going since it never receives a command to shut down. Changing a thermostat should not be difficult. You can likely find a replacement unit by visiting the manufacturer's website or calling customer service.

Compressor

• The compressor is the football-sized black metal box on the back of the refrigerator. This is where the grunt work is done of compressing refrigerant into gaseous form in order to provide cooling to the interior compartment. A compressor might run continuously for several reasons, but all relate to trying to provide as much cold air as it thinks is being demanded. It will try to push this air with mindless efficiency until the point of failure.

Refrigerant

• Cooling inside a refrigerator is accomplished through the transformation of a liquid refrigerant to a gas state and back. Though it is supposed to be a closed system, sometimes leaks do occur, or perhaps the appliance was undercharged from the factory. When a low level of refrigerant is present, the compressor continues to run in spite of instructions from the thermostat to the contrary. Only a certified professional should attempt refrigerant recharging.

Considerations

• A compressor must generate tremendous compression to do its job. This mechanical effort generates a lot of heat, and frequent down time between shifts is necessary to prevent overheating. A compressor that runs too long and overheats will likely die before its time, leaving you with a refrigerator full of food destined for spoilage and requiring either an expensive repair or the purchase of a new appliance.