Thermador Range Error Code F46

The F46 error code on a Thermador range indicates a contradictory signal from the lower oven door latch assembly. Specifically, the control system is simultaneously detecting both a locked and an unlocked state from the latch switches, which is a logical impossibility under normal operating conditions. This conflict typically arises during or after a self-clean cycle, when the latch motor engages to secure the door at high temperatures. The Power Board monitors the latch position through dedicated switch inputs, and when both signals are active at the same time, the board registers a fault and halts operation to prevent unsafe conditions.

The door latch assembly on this range uses two micro-switches to confirm position: one signals the fully locked state, and the other confirms the unlocked state. When both report active simultaneously, it usually points to a wiring or connector issue rather than both switches failing outright. The P24 connector on the Power Board is the primary interface for these latch signals, making it the first point of inspection. A loose, corroded, or improperly seated connector can cause false simultaneous signals by allowing voltage to bleed across circuits.

Pinched or damaged wiring in the latch harness is another frequent contributor, particularly in installations where the door has been serviced or where repeated high-heat cycles have degraded wire insulation. If the wiring and connectors check out correctly and the switches themselves test within proper operating parameters, the fault likely originates within the Power Board itself, which may be misreading or short-circuiting the latch input signals internally. In that case, replacing the Power Board is the recommended resolution.