LG Oven F1 Error Code — What It Means
The F1 code tells you the control board has lost a clean reading from the upper oven temperature sensor, also called the thermistor. It usually points to an open circuit in the sensor or its wiring, so the oven can no longer trust the temperature it sees and shuts down the heating function.
On most LG ranges a healthy sensor reads close to 1080 to 1100 ohms at room temperature. A reading of zero or no continuity means the sensor has failed.
Common Causes
- Failed oven temperature sensor The thermistor itself has gone open and no longer changes resistance with heat.
- Damaged sensor wiring A burnt or pinched wire between the sensor and the control board breaks the circuit.
- Loose harness connector The plug where the sensor meets the main board has backed out or corroded.
- Sensor probe touching metal A bent sensor tip contacting the oven wall can short the reading and trip the code.
- Failed main control board Less often, the board input that reads the sensor has failed even though the sensor is good.
Step-by-Step Fix
- Press CLEAR/OFF and try the original function again to clear a one-time glitch.
- If the code returns, turn off the breaker for 30 seconds, then restore power and retest.
- Pull the range and remove the sensor screws inside the oven cavity to access the probe.
- Unplug the sensor harness and measure resistance with a multimeter at room temperature.
- Replace the sensor if it reads zero, infinite, or far from about 1080 to 1100 ohms.
- Inspect the harness for burnt spots and reseat the connector at the control board.
- Restore power and run a short bake cycle to confirm the code stays clear.
Parts Often Needed
| Part | Notes |
|---|---|
| LG oven temperature sensor (thermistor) | Amazon | Match to your exact model number since probe length and plug vary. |
| Oven sensor wire harness | Amazon | Order only if the wiring shows burn marks or broken strands. |
| Range main control board | Amazon | Last resort if the sensor tests good but the code stays. |
When to Call a Pro
Call a technician if the sensor tests within spec and the code returns after reseating connectors, since that points to the main control board. Anyone uneasy pulling the range or working near 240 volt wiring should also bring in a pro.