Thermador Range Error Code F43

F43 indicates that the upper or single oven motorized door latch has failed to complete its unlock sequence. This most commonly occurs at the end of a self-clean cycle when the latch should retract to release the door. On Sago platform models, F43 can also indicate that the lower oven RTD sensor has not been properly calibrated. The fault points to the Power Board, latch switches, or associated wiring as the likely source of the problem.

If the F43 code has triggered because the oven door is physically latched shut, you should not attempt to force the door open. Avoid running the oven, especially the self-clean function, until the fault is resolved. A stuck motorized latch means the locking mechanism is not operating correctly, and continued use without diagnosis could worsen the underlying issue or prevent the door from opening at all.

Repair costs vary depending on which component has failed. If only a connector needs reseating or a wire needs repair, costs may be minimal beyond a service call fee, which typically ranges from around 75 to 150 dollars. Latch switch replacement parts generally range from 30 to 80 dollars depending on the model. A Power Board replacement is the most expensive outcome, with parts typically ranging from 150 to 400 dollars or more, plus labor if a technician performs the repair.

Some of the diagnostic steps are accessible to a knowledgeable DIYer, including inspecting and reseating the P4 and P10 connectors on the Power Board and visually checking wiring for pinching or damage. However, testing the door latch switches for proper continuity and actuation requires a multimeter and some familiarity with appliance wiring. If the Power Board needs replacement, that repair is more involved and may be best handled by a qualified technician.

A power reset by disconnecting the range from power for several minutes may temporarily clear the fault display, and in some cases the latch motor may complete its cycle once power is restored. However, if there is an underlying problem with the latch switches, connectors, wiring, or Power Board, the F43 code will return. A reset alone is not a repair and should only be used as part of the diagnostic process.