Thermador Range Error Code F126

F126 indicates a circuit problem with the Lower Cancel key on the control keyboard. The range's control system has detected an abnormal signal from that key's circuit, which runs between the keyboard connector J1 and Display Board connector P5. This fault typically points to a connection issue, a failed keypad, or a faulty Display Board.

The F126 error relates to the Lower Cancel key circuit, which is a control input issue rather than a heating or gas system fault. However, when a fault code is active, the range may lock out certain functions or operate unpredictably. It is best to avoid relying on the appliance until the fault is diagnosed and repaired.

Repair costs vary depending on which component has failed. If only the keyboard assembly needs replacement, parts and labor together typically range from around $150 to $400. If the Display Board also requires replacement, costs can run from $250 to $600 or more depending on part pricing and the technician's labor rate in your area.

A knowledgeable DIYer can start by checking that the ribbon cable between the keyboard and the Display Board is fully seated and undamaged. If the connections look secure and clean, resolving the fault will likely require replacing the keyboard assembly or the Display Board, which involves disassembling the control panel area. If you are not comfortable working with control board components, a qualified appliance technician is recommended.

Cycling power to the range may temporarily clear the F126 code, but if the underlying circuit problem with the Lower Cancel key persists, the error will return. A reset does not repair a loose connection, failed keypad, or faulty Display Board. A proper diagnosis and repair is needed to permanently resolve the fault.