LG Oven Error Code F-9

The F-9 code means the upper oven failed to reach 150°F (66°C) within 5 minutes of starting a heating cycle. The control board monitors temperature rise during preheat, and when it does not detect adequate heat in that window, it faults with F-9. This points to a problem in the heating circuit, which includes the heating element, the DLB relay controlling the L2 power leg, and the wiring between them.

No. When F-9 is active, the upper oven is not heating properly, which means food will not cook safely or evenly. More importantly, an underlying wiring or relay fault can present a fire or electrical hazard. The oven should not be used until the cause of the error has been identified and repaired.

Repair costs vary depending on the failed component. A replacement upper oven heating element typically costs between $30 and $100 for the part. A DLB relay or control board replacement can range from $80 to $250 or more depending on the part. Adding professional labor, total repair costs commonly fall between $150 and $400, though this varies by region and the specific parts required.

Some steps, such as inspecting visible wiring connections and testing component resistance with a multimeter, are within reach for a knowledgeable DIYer comfortable working on appliances. However, the upper oven circuit operates on 240V, which is dangerous if not handled carefully. Replacing a heating element is a moderately straightforward repair, but testing and replacing a DLB relay or control board is best handled by a qualified technician if you are not experienced with high-voltage appliance circuits.

A power reset by unplugging the oven or turning off its circuit breaker for a few minutes may temporarily clear the code, but it will return as soon as a heating cycle is attempted again if the underlying fault is not repaired. The F-9 code is triggered by a real hardware failure in the heating circuit, and no amount of resetting will fix a failed element, relay, or wiring problem.