E4
Whirlpool
Defrost Sensor / Evaporator Thermistor Fault
Display shows E4, refrigerator may not defrost properly, frost buildup on evaporator cover.
Advertisements
Safety Warning
This repair may involve working with high voltage components or water connections. Always unplug the appliance before removing any panels.
If you are not confident in your ability to perform this repair safely, we strongly recommend contacting a professional technician.
Advertisements
Possible Causes
Open defrost thermistor, Shorted defrost thermistor, Damaged wiring to evaporator sensor, Main control board sensor circuit failure
How to Fix / Troubleshooting
Safety First: Unplug the refrigerator. Be cautious of sharp evaporator fins.
Steps:
- Access the evaporator: Remove freezer baskets and the rear evaporator cover. If heavily iced, allow to defrost or use a hair dryer on low.
- Locate the defrost thermistor: It is clipped to the evaporator tubing or mounted near the top of the evaporator coil.
- Inspect sensor and wiring: Look for broken clips, damaged insulation, or corroded connectors.
- Test resistance: Disconnect the thermistor and measure resistance at the current temperature. Compare to the Whirlpool chart. Replace if open, shorted, or out of spec.
- Check harness: Verify continuity from the thermistor connector to the main control board. Repair any open or shorted wires.
- If the thermistor and wiring are good, replace the main control board.
Advertisements
Repair Difficulty
Hard
4/5
Required Part
Defrost Thermistor
Check Price on Amazon
We may earn a commission from links on this page.
Advertisements