How an LG wall oven signals trouble
An LG wall oven watches its cavity through an RTD sensor and runs bake, convection and self-clean through an electronic control, so a fault shows up as an F-code. Reading the code is the start of any LG oven repair, because each one points at the sensor, the control board, the keypad or the door lock. LG wall ovens are electric and come as single WSEP and double WDEP cavities, plus the WCEP combo that pairs an oven with a microwave.
The F-series codes
F1 is an upper-oven thermistor open or short, and F4 the lower thermistor — the most common cause of erratic baking or a no-heat cavity. F2 is a runaway high-temperature condition; turn the breaker off. F3 is a shorted keypad key, F6 an overheat or stuck relay, F7 the convection fan, and F9 an oven that will not heat. F10 and F20 are upper and lower door-lock faults, F11 a comms fault between boards, and F27 a cooling fan stalled during self-clean. On a double oven, note which cavity shows the code — each has its own sensor and lock.
Status words versus stored faults
Not every message is a fault. PF is a power failure, 5b is Sabbath mode, CL is Clean-Lock, and LOC is the child or control lock. A door that will not unlock after self-clean is usually the latch needing a cool-down or a cycle, not a failed part — though it can be.
What to check, and when to call
A keypad lockout or a one-off PF often clears with a breaker cycle. A persistent F1/F4 sensor code, an F2 runaway, an F9 no-heat condition or a latch fault that leaves the door locked needs an experienced technician with genuine parts. See the oven F-codes guide, the F9 not-heating guide and the guide to a door that will not unlock, browse the error codes library, then book oven repair. Confirm your model on the manufacturer’s site at lg.com/us.