Brand: Whirlpool
Model Number: WRF535SMB00
Main Symptom: Frig Warm
What happens & when:
Error Code (if any):
Parts or tests already tried:
Photos / video link:
Fans function fine. Damper open in frig. Defrosted a month ago and all functioned fine for 30 days now coils heavily frosted again
1. Unplug the refrigerator.
2. Access the evaporator.
Remove the freezer baskets and rear freezer panel. You’ll find the defrost heater attached to the evaporator coils and the defrost thermostat clipped to the tubing near the top of the evaporator.
Disconnect at least one heater wire.
Set your meter to Ohms (Ω).
Place a meter lead on each heater terminal.
Results:
Typically 20–30 Ω = heater is good.
OL/no continuity = heater is open and needs replacement.
Important: The thermostat must be cold to test properly (below about 40°F). If it’s warm, it should test open.
Leave the thermostat clipped to a frosted evaporator or place it in a cup of ice water for several minutes.
Disconnect the thermostat wires.
Set your meter to continuity or the lowest ohms scale.
Touch one meter lead to each thermostat wire.
Results:
Cold thermostat: Should show continuity (0–1 Ω or meter beeps).
Warm thermostat: Should show OL/no continuity.
If it’s cold and still reads OL, the thermostat has failed and should be replaced.
| Test | Good Reading | Bad Reading |
|---|---|---|
| Defrost Heater | ~20–30 Ω | OL/Open |
| Defrost Thermostat (Cold) | Continuity / 0–1 Ω | OL/Open |
| Defrost Thermostat (Warm) | OL/Open | Continuity |
If the heater and thermostat both test good but the evaporator is icing over, the problem is likely in the Jazz control board (adaptive defrost control) or wiring.