LG Oven F2 Error Code — What It Means
The F2 code on an LG range is an upper oven thermistor error. LG’s official support documentation identifies this as a problem in the temperature-sensing circuit for the upper oven cavity. The control board has detected that the thermistor (the small sensor that monitors oven temperature) is reading outside normal range, shows a short, or is not communicating correctly. In most cases this points to a defective sensor, damaged wiring between the sensor and the control board, or a failed main control board that can no longer read the sensor signal properly.
Common Causes
- Defective upper oven thermistor The sensor itself has failed internally, reads out of specification, or has become intermittent due to age or heat exposure.
- Damaged or loose wiring to the sensor The harness or connectors between the thermistor and control board are broken, pinched, corroded, or have worked loose over time.
- Failed main control board The circuit on the control board that reads and interprets the thermistor signal has failed even though the sensor itself is good.
- Heat-damaged connectors at the sensor High oven temperatures over time can melt or degrade the plastic connector terminals where the sensor plugs in.
Step-by-Step Fix
- Press CLEAR/OFF and try the oven again. LG recommends this reset as the first step in case the code was triggered by a momentary glitch.
- Power off the range completely at the circuit breaker and wait two minutes, then restore power. If the code returns immediately or during the next heating cycle, continue diagnosis.
- Disconnect power at the breaker and pull the range forward to access the rear panel. Remove the back cover to expose the upper oven thermistor and wiring.
- Inspect the thermistor and its harness for burned insulation, loose or corroded terminals, pinched wires, or heat damage. Wiggle the connector gently to check for intermittent contact.
- Test the thermistor with an ohmmeter at room temperature. Disconnect the sensor from the harness, measure resistance across its two terminals, and compare the reading to the specification in your model’s service manual or parts documentation. An open circuit, short, or out-of-range reading confirms a bad sensor.
- Replace the upper oven thermistor if it tests defective or shows visible damage. Route the new sensor into the oven cavity in the same position, secure it with the mounting clip, and reconnect the harness.
- Replace the main control board if the thermistor tests good, the wiring is intact, and the F2 code persists after reassembly and a power cycle. Clear all power before swapping boards and transfer connections carefully one at a time.
Parts Often Needed
| Part | Notes |
|---|---|
| LG upper oven thermistor / temperature sensor | Amazon | Confirm fit by your range’s full model number, usually found inside the door or on the back panel. |
| LG range main control board / PCB | Amazon | Only needed if the sensor and wiring test good but the error remains. |
When to Call a Pro
If you are uncomfortable working with 240-volt power or testing electrical components with a meter, call a qualified appliance technician. The thermistor itself is inexpensive and straightforward to replace for anyone familiar with basic hand tools and safe disconnect procedures, but diagnosing control board faults or tracing intermittent wiring problems requires experience. If the code clears after a reset but returns unpredictably, the problem may be intermittent and harder to isolate without test equipment and knowledge of the circuit. A technician can also access factory service manuals that list exact resistance specifications for your model’s sensor.