LG Microwave Error Code F-2 — Oven Cavity Thermistor Error
What this means
The F-2 error code on LG microwaves indicates the cavity thermistor (temperature sensor) is reading outside its expected range — either open circuit, shorted, or giving erratic values. This sensor monitors the internal temperature of the microwave cavity and helps prevent overheating. When it fails, the microwave may shut down as a safety precaution.
Alternate codes: F2
Step-by-step fix
4 stepsPower cycle the microwave
Unplug the microwave for five minutes and plug it back in. If the error clears, run a short heating test. A temporary temperature spike or electrical glitch can cause a false F-2.
If the microwave was just used for an extended cook session, let it cool for 30 minutes before testing.
Locate the thermistor
Unplug the microwave. Remove the outer cabinet. The cavity thermistor is typically a small sensor mounted to the interior wall of the cavity housing, connected to the control board by a two-wire harness.
WARNING: Do not touch the high-voltage capacitor or magnetron. Work only in the area near the sensor and control board.
Test the thermistor
Disconnect the thermistor wires and measure resistance with a multimeter. At room temperature, LG microwave thermistors typically read between 5,000–10,000 ohms (varies by model). OL or 0 ohms indicates a failed sensor.
Check the tech sheet inside the cabinet for the exact expected resistance for your model.
Replace the thermistor
If the sensor reads outside its expected range, remove the mounting clip or screw, disconnect the old sensor, and install the replacement. Reassemble the microwave and run a heating test.
Ensure the replacement sensor is routed and secured the same way as the original to avoid pinching.
When to call a professional
If the thermistor tests good but F-2 persists, the control board's temperature input circuit may be damaged. A qualified technician should diagnose the board due to the high-voltage components present.
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
Cavity Thermistor
Part #MEE62805104 · $10–$25
If sensor reads outside the expected resistance range
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