LG Oven Error Code F-8

The F-8 code means the upper oven temperature probe thermistor has been detected in a shorted state for more than one minute after a cook cycle starts. The oven control board monitors the resistance signal from the upper probe continuously, and when the signal indicates a short rather than a valid temperature reading, the oven shuts down and displays this fault. The most common causes are a failed probe, damaged wiring, or corroded connectors.

No, you should not use the oven while F-8 is active. The fault indicates the control system cannot accurately monitor the upper oven temperature, which means the oven could overheat without the control board detecting it. Continuing to operate the oven under these conditions poses a risk of overheating, potential food safety issues, and possible damage to the appliance.

Resetting the oven by turning off the breaker for a few minutes may temporarily clear the F-8 code, but the fault will return once a cook cycle starts if the underlying problem has not been resolved. Because the code triggers only after the shorted condition persists for over one minute into a cook cycle, a reset alone does not fix the failed probe, damaged wiring, or other root cause. A proper repair to the temperature probe or wiring is required to resolve the fault permanently.

Replacing an upper temperature probe is a repair many experienced DIYers can handle, as the probe typically mounts with one or two screws inside the oven cavity and connects via a wiring harness. However, inspecting and repairing the wiring harness or replacing the control board requires more comfort with electrical diagnostics and disassembly. Always disconnect power to the oven at the breaker before performing any internal inspection or repair.

If the upper temperature probe is the failed component, replacement probes typically cost in the range of $20 to $60 for the part, with professional labor adding $75 to $150 depending on your area. If the control board is the root cause, board replacement parts alone can range from $100 to $300 or more, making that a more expensive repair. Getting a diagnostic call from a technician first can help confirm which component has actually failed before committing to parts.