Thermador Oven Error Code E12

E12 on a Thermador oven indicates a control board problem. The error code appears in the COOK MODE display window and makes the oven completely unusable while active. It can result from a temporary electrical disturbance or a hardware failure within the control board itself.

No. When E12 is active, the oven is locked in an error state and is not functional. You should not attempt to operate the oven while this code is displayed. Disconnect power and perform the reset procedure before attempting any further use.

Replacing a control board is a task that requires comfort working with electrical components and correctly disconnecting and reconnecting wiring harnesses. A knowledgeable DIYer may be able to perform the replacement, but because the oven operates on 240-volt power, there is a serious shock hazard if the appliance is not fully disconnected from power before any work begins. If you are not confident working with high-voltage appliances, hiring a certified technician is the safer option.

A power reset is the first recommended step and will clear the error in cases where it was triggered by a temporary electrical disturbance. Turn off the power at the circuit breaker, wait at least one minute, and restore power. If the E12 code returns after the reset, a deeper hardware issue with the control board is likely present.

If the issue is resolved by a power reset, there is no parts cost involved. If the control board requires replacement, parts alone can range from roughly $150 to $400 or more depending on the specific model, with professional labor adding additional cost. Getting a diagnosis from a qualified technician before ordering parts is advisable.