LG Oven F9 Error
What it means
F9 means the oven is not heating properly — specifically, the oven failed to reach about 150°F (65°C) within roughly 5 minutes of being turned on. LG's control board watches the temperature climb during preheat, and if it doesn't rise fast enough the board reports F9 and stops heating as a safety measure. A quick reset clears glitches, but if it returns the fault usually points to a heating component or the control board rather than something you set wrong.
Common causes of the F9 error
- Temporary control glitch that a reset will clear
- Faulty relay board (the most common hardware cause)
- Failed bake or broil heating element (electric models)
- Weak or failed igniter that won't reach ignition temperature (gas models)
- Defective oven temperature sensor (thermistor)
- Loose or damaged wiring between the sensor, element, and control board
How to fix the LG Oven F9 error
- 1Press CLEAR/OFF and retryPress the CLEAR/OFF key to cancel, then start the same cooking function again. A one-time glitch often clears here.
- 2Power-cycle at the breakerIf the code returns, switch the oven's circuit breaker off, wait about 30 seconds, and turn it back on. This fully resets the control board.
- 3Confirm the oven actually warmsAfter resetting, set a normal bake temperature and check whether the oven begins to heat at all within a few minutes. If it stays cold, a heating component is likely at fault and needs service.
🧰 When to call a professional
If F9 reappears after pressing CLEAR/OFF and power-cycling the breaker, the unit requires service. Diagnosing and replacing the relay board, heating element, igniter, or temperature sensor involves live electrical (or gas) connections and disassembly, so schedule a repair through LG Support or a qualified appliance technician rather than attempting it yourself.
LG F9 error — FAQ
What does the F9 code mean on an LG oven?
F9 means the oven is not heating properly — it did not reach about 150°F within roughly 5 minutes, so the control board stopped heating as a safety measure.
How do I reset the F9 error?
Press CLEAR/OFF and try the function again. If it returns, turn the oven's circuit breaker off for 30 seconds, then back on to reset the control board.
Why does F9 keep coming back?
A recurring F9 usually points to hardware — most often a faulty relay board, but also a failed heating element, igniter, or temperature sensor. These require professional service.
Sources
This guide is independently written and not affiliated with LG. Always unplug appliances before servicing and follow your model's manual. Error codes and steps can vary by model — when in doubt, consult a qualified technician.