LG Oven/Range Error Code F3 — Oven Temperature Sensor Shorted
What this means
The F3 error code on LG ovens indicates the temperature sensor (thermistor) has a short circuit — its resistance is abnormally low, close to 0 ohms. The control board reads this as an impossibly high temperature and shuts down heating to prevent damage. Common causes include a cracked sensor probe that has allowed moisture in, pinched wiring, or melted insulation allowing bare wires to contact the chassis.
Step-by-step fix
4 stepsPower cycle and check for moisture
Turn off the breaker for two minutes. If the oven was recently used to cook something very moist (roast, casserole), condensation may have temporarily shorted the sensor. Allow the cavity to dry completely, then restore power and test.
Leaving the oven door cracked open for 15–20 minutes after a moist cook helps evaporate condensation faster.
Test the sensor resistance
Turn off the breaker. Access the sensor wiring from behind the range. Disconnect the two-wire connector and measure resistance. A good LG oven sensor reads about 1,080–1,100 ohms at room temperature. A reading near 0 ohms confirms a short.
If the reading at the sensor end is normal but near 0 at the board connector, the wire harness is shorted along its route.
Inspect wiring for insulation damage
Trace the sensor leads from the probe to the control board. Look for places where insulation has melted or bare copper is touching the oven chassis. Repair or replace damaged sections.
Use high-temperature wire rated for oven environments when splicing — standard electrical tape will melt.
Replace the sensor
If the sensor itself is shorted, remove the mounting screw(s) from inside the oven cavity, pull the old sensor out, install the new one, and reconnect the harness. Run a bake cycle to confirm F3 clears.
Verify accuracy at 350 °F with a standalone oven thermometer after replacement.
When to call a professional
If the sensor and wiring both test good but F3 keeps appearing, the control board may have an internal short on its sensor input. A technician should diagnose the board.
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 near 0 ohms (short circuit)
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