Whirlpool Microwave Error Code F4 — Humidity/Temperature Sensor Short
What this means
The F4 error code on Whirlpool microwaves indicates a shorted sensor — either the humidity sensor (used for auto-cook and auto-reheat modes) or the oven temperature sensor (in combination microwave/convection models). A shorted sensor sends abnormally low resistance readings to the control board, preventing automatic cooking modes from functioning properly. Manual time/power cooking may still work.
Step-by-step fix
3 stepsTry manual cooking
Test if the microwave heats food using manual time and power settings. If manual cooking works, the issue is specifically with the sensor used for automatic modes.
You can continue using the microwave with manual settings while waiting for repair.
Power cycle the microwave
Unplug for 5 minutes to reset. If steam or moisture caused a temporary sensor reading, this may clear the error.
Cooking foods that generate heavy steam can temporarily affect sensor readings.
Contact a professional for sensor replacement
The humidity and temperature sensors are located inside the microwave cabinet. Due to the high-voltage capacitor inside, professional service is required to access and replace them.
Provide the technician with the F4 code and your model number to ensure they bring the correct sensor.
When to call a professional
Sensor replacement requires opening the microwave cabinet — always hire a professional for this repair.
Related error codes
Information compiled from manufacturer service manuals, official troubleshooting documentation, and appliance repair industry resources. This guide is for informational purposes only — always consult a qualified technician for complex repairs.
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