Model #FRT18L4JW5, this top mount, freezer on top, refrigerator was only four months old when the customer noticed the unit seemed to intermittently cool. Sometimes they would arrive home to warm food inside, then after playing with the temperature controls, it would start cooling again. With Thanksgiving quickly approaching, the customer was hoping for a refrigerator that would keep things cold.



When I arrived at the home, the unit seemed to be cooling just fine as indicated by the frozen Cool Whip in the freezer, but fortunately when I contacted the customer the night before, he had mentioned he was an HVAC technician which means we were able to speak the same language. After doing some of his own checks, he determined the mechanical cold control was no longer working properly giving me reason to have one handy when I arrived.

The cold controls on these units are a simple mechanical switch which opens and closes a set of electrical contacts depending on the temperature inside the cabinet. Using a very small amount of refrigerant in a capillary tube as a sensor, as the inside gets warmer the refrigerant will expand closing the contacts and turning the compressor on. Once cold enough, the refrigerant will compress and the contacts will open. The consumer is able to adjust the temperature by changing the distance the refrigerant needs to expand before the contacts close.

Because the unit was cooling, we knew the contacts were functioning and when the compressor was off, the cold control could be turned to a cooler temperature forcing the compressor on. The problem seemed to be once the cold control was down to the set temperature and the contacts opened, they would not close again until the control was manually adjusted.

With the information from my HVAC customer, and some brief testing while on site, I changed the cold control inside the upper panel inside the fresh food section. Once changed out and the wiring was all back in place, I again applied power and set the control for the lowest set temperature to ensure it would cycle off, and back on as expected. The refrigerator was back in working order and ready for the Thanksgiving meal.


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