Frigidaire Microwave Error Code F1 — Thermal Sensor Open Circuit
What this means
The F1 error code on Frigidaire microwaves indicates the thermal sensor (thermistor) inside the oven cavity has an open circuit. This sensor monitors the temperature to prevent overheating and supports sensor cooking programs. When the circuit is open, the microwave cannot determine internal temperature and will not operate as a safety measure.
Step-by-step fix
3 stepsReset the microwave
Unplug the Frigidaire microwave for 5 minutes, then plug it back in. A temporary sensor glitch or loose connection may resolve after a full power reset.
If the microwave was recently running at high power for an extended period, let it cool for 20 minutes before resetting.
Access and test the thermal sensor
Unplug the microwave. Remove the outer cabinet cover by removing the screws. SAFETY: Do not touch the high-voltage capacitor. Locate the thermal sensor on the oven cavity wall. Disconnect its wires and test with a multimeter — at room temperature, expect approximately 50,000–60,000 ohms. An open (infinite) reading means the sensor has failed.
Frigidaire microwaves are manufactured by Electrolux — parts may be listed under either brand name.
Replace the thermal sensor
Remove the mounting clip or screw holding the sensor. Install the new sensor in the same location. Reconnect the wires and reassemble the outer cabinet.
Ensure the sensor wires are routed away from the magnetron and other heat-producing components to prevent premature failure.
When to call a professional
Microwave internal repairs involve high-voltage components. Professional service is strongly recommended unless you have specific experience with microwave 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.
Learn more about our sourcesParts you may need
Links may earn us a commission at no extra cost to you. We only recommend parts relevant to this repair.