Thermador Range Error Code F80

F80 on a Thermador range means the lower oven door signal circuit is shorted low. The control system expects a dynamic signal from the door switch that changes when the door opens and closes, but it is instead reading a stuck low condition. This fault involves the door switch, the wiring harness, and the connection headers on the power/relay board and control display PCB.

It is not recommended to continue using the oven while F80 is active. The error indicates the control system cannot properly read the lower oven door position, which can affect functions that depend on door status for safe operation. The fault should be diagnosed and resolved before resuming normal use.

A power reset by unplugging the range or turning off the circuit breaker for a few minutes may temporarily clear the F80 code, but it will return if the underlying fault is still present. Resetting is useful for confirming whether the fault is persistent or intermittent, but it does not address the shorted wiring, failed switch, or board issue causing the code.

Some causes of F80 are accessible to a knowledgeable DIYer, such as inspecting for a pinched wire or reseating connectors at headers P5 and P11. Verifying the door switch operation is also a manageable task. However, if the fault requires replacing the power/relay board or control display PCB, comfort with appliance electronics and disassembly is needed, and professional service is recommended if you are unsure.

Repair costs vary depending on the root cause. If the issue is a pinched wire or a failed door switch, parts and labor costs are typically lower, often in the range of $100 to $250. If the power/relay board or control display PCB needs replacement, costs can rise to $300 to $600 or more depending on parts pricing and labor rates in your area.