Kenmore Microwave Error Code F1 — Thermistor Open
What this means
Error F1 indicates the microwave's internal temperature sensor has an open circuit. The thermistor monitors cavity temperature for sensor cooking and reheat functions. A broken sensor wire or failed thermistor element triggers this code.
Step-by-step fix
4 stepsUnplug the microwave
Disconnect power completely before any troubleshooting.
Microwaves contain a high-voltage capacitor that can hold a lethal charge even when unplugged. Exercise extreme caution.
Test the thermistor
If accessible, test the thermistor with a multimeter. It should show resistance at room temperature.
An open (infinite) reading confirms the sensor has failed.
Check wiring
Inspect the sensor wiring for damage or disconnection.
Replace the thermistor
If the sensor is defective, replace it.
When to call a professional
Due to the high-voltage capacitor in microwaves, professional service is strongly recommended for any internal repairs.
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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