- The SEN00347 Trane Heat Pump Defrost Sensor is a brand new Trane, American Standard heat pump defrost sensor that comes in a sealed Factory Specified Parts bag.
- The SEN00347 replaces part numbers: COL04500, SEN00257, SEN00625, SEN00727, SEN00728 and SEN00729.
- If your heat pump looks like a block of ice in the winter time then you might need a new defrost control board or defrost thermostat. I believe it is a good idea to replace both the defrost control board and the thermostat.
- Other problems that can cause heat pump freeze ups are: (1) if the system is low on refrigerant charge or (2) if you have a bad defrost thermostat (3) If your contactor is stuck closed on the outdoor unit. (4) Poor air flow on the outdoor unit by having a dirty coil or a dragging fan motor. You might need a new capacitor on your fan motor.