Jason for Model Number PFSS5NFWASS Over freezing in freezer section causing ice to build up and hitting the fan. Defrost heater checked good, Would this be a failed sensor or control board?
Answer Jason, the defrost heater should have a resistance of 31.2 ohms. If the heater has the proper resistance, then the next thing to check would be the defrost thermostat WR50X10069 The defrost thermostat should read continuity when it has reached 15 degrees Fahrenheit or if the ice is built up. If it does not read continuity, then it has failed. If those check good then you may want to test the evaporator thermistor at the main control. With the power turned off, you will want to go to connection J1 of the main control WR55X10956 and test from pin 4 to pin 5 for resistance. The resistance would need to be compared to actual temperature. If the thermistor checks good then the main control WR55X10956 would be the most likely issue. Further information will be sent to assist with testing. Read More... Answered by AppliancePartsPros.com | Friday, May 31, 2019