Thermador Cooktop Error Code W0

The W0 code means the cooktop has measured an input voltage above 280 volts, which is beyond its safe operating limit. The appliance triggers this code and shuts down to protect its internal electronics from overvoltage damage. The problem is almost always related to the incoming electrical supply or the wiring rather than a component failure inside the cooktop itself.

Simply resetting the cooktop will not permanently clear the W0 code if the underlying overvoltage condition still exists. The code will return as soon as the appliance detects that the input voltage is still above 280V. The supply voltage and wiring must be corrected first, after which the error should not reappear on a normal power cycle.

If the cause is a wiring or supply issue, costs are typically limited to an electrician's service call, which can range from around $100 to $300 or more depending on the extent of the work needed. If the control board has been damaged by the overvoltage event and requires replacement, parts and labor costs can range from several hundred dollars upward depending on the specific board and local labor rates.

No. The cooktop should be disconnected from power immediately when W0 appears. Operating the appliance with an input voltage above 280V risks permanent damage to the control board, induction drivers, and other electronics. The electrical supply must be confirmed to be within the correct voltage range before the cooktop is reconnected.

Start by disconnecting the cooktop from power, then use a calibrated multimeter to measure the voltage at the supply outlet or junction box. If the voltage is above the normal range, contact your utility provider and a licensed electrician to address the supply issue. If the supply voltage is normal, inspect all wiring connections at the circuit breaker, outlet, and cooktop terminal block for loose, broken, or incorrectly wired conductors.