LG Oven/Range Error Code F1 — Oven Temperature Sensor Open Circuit
What this means
The F1 error code on LG ovens means the electronic control board has detected an open circuit in the oven temperature sensor (also called a thermistor or RTD). The sensor wire may be broken, the connector may be loose, or the sensor element itself has failed. The oven will not heat until the sensor circuit is restored because the board cannot monitor cavity temperature.
Step-by-step fix
4 stepsPower cycle the oven
Unplug the range or turn off the breaker for two minutes. Restore power and start a bake cycle. If the code clears, a one-time wiring glitch may have been the cause.
If the error returns immediately, proceed to sensor testing.
Locate and test the temperature sensor
The sensor is a thin metal probe mounted at the upper rear wall of the oven cavity. Access the wiring from behind the range by removing the rear panel. Disconnect the sensor connector and measure resistance with a multimeter — at room temperature (~75 °F), a good LG sensor reads about 1,080–1,100 ohms.
An OL (open line) reading confirms the sensor or its wiring has an open circuit.
Inspect the wiring harness
If the sensor itself reads in range but the connector at the board reads OL, there is a break in the harness. Trace the wires from the sensor to the board, looking for heat damage, pinched wires, or rodent damage.
The pass-through point at the rear oven wall is the most common location for insulation failure.
Replace the temperature sensor
Remove the mounting screw(s) inside the oven, pull the probe out through the rear wall, disconnect the old harness, and install the new sensor. Restore power and verify the oven heats to the set temperature.
Use a standalone oven thermometer to confirm the replacement sensor reads accurately.
When to call a professional
If the new sensor and wiring are good but F1 persists, the control board's sensor input circuit may be damaged and should be evaluated by a technician.
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
Oven Temperature Sensor
Part #MEE62805106 · $10–$25
If sensor reads OL (open line) on multimeter
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