Cindy for Model Number ZFSB23DRDSS The freezer is fine but the refrigerator is not cooling. There is a block of ice on the cover of the evaporator unit. How many thermistors are there in the refrigerator and where are they? What part do I need? How do I know if the main control board is bad? I unplugged the refrigerator and the ice has melted and the temperature is now 34 degrees. I know it's temporary until the ice builds up again.
Answer Cindy, there is an evaporator thermistor WR55X10025 (located near the evaporator) and a refrigerator section thermistor WR55X10025 (located on the right side of the refrigerator behind a slatted cover). The thermistors would need to be tested from the main control to identify which component has failed. With the refrigerator unplugged and a thermometer in the refrigerator section, the evaporator thermistor would be tested at the connection J1 from the blue/red wire at pin 1 to the blue wire at pin 5 for resistance. The measurement should read more than 21KO with a proper frost pattern on the evaporator. The refrigerator section thermistor would be tested from the blue wire at pin 5 to the yellow wire at pin 2. The measurement should read 16.3KO at 32°F, 12.7KO at 41°F, and 10KO at 50°F. If the thermistors test properly, then it is likely that the main control WR49X10152 is not allowing the refrigerator to defrost as necessary. Read More... Answered by AppliancePartsPros.com | Tuesday, June 9, 2020