Thermador Cooktop Error Code W3

The W3 error code on a Thermador induction cooktop indicates that the induction electronics have reached an unsafe operating temperature. Specifically, this thermal overload condition is detected within the main board (MB) or the auxiliary driver board (ADB), both of which are responsible for generating and controlling the high-frequency alternating current that powers the induction coils. When internal temperature sensors on these boards detect temperatures beyond the safe operating threshold, the unit triggers an automatic shutdown to prevent component damage.

The auto shut-off function is a protective measure built into the electronics to preserve the integrity of the power switching components, including the IGBT transistors and capacitors on the MB and ADB boards. These components are particularly sensitive to heat, and sustained overtemperature conditions can cause permanent failure. The cooktop will not resume operation until the board temperatures drop to a safe level and a reset is performed.

Common triggers for W3 include restricted airflow around or beneath the cooktop, a failed or obstructed cooling fan, extended high-power cooking sessions in warm ambient conditions, or an underlying fault in one of the boards causing it to draw excessive current and generate abnormal heat. In some cases, legitimate heavy use is the sole cause, and the unit will return to normal operation after cooling. Repeated or frequent W3 errors under normal use conditions suggest a cooling system fault or a degrading board component that warrants closer inspection.