Zenith Dishwasher Error Code F12

F12 on a Zenith dishwasher indicates a temperature sensor high fault. The dishwasher's control board is receiving a signal from the NTC thermistor that the water temperature is abnormally high, or the sensor has become stuck reporting a high reading. The dishwasher stops operation to protect internal components. The cause is usually a failed sensor, a wiring short, or a control board fault.

You should not continue running the dishwasher while F12 is active. The error indicates either a genuine overheating situation or a sensor fault, and in either case the appliance has halted operation as a protective measure. Running it in a fault state could cause damage to the tub, door seals, or internal electronics.

A power reset by disconnecting the dishwasher from power for several minutes may temporarily clear the F12 code, but it will return if the underlying fault is not repaired. If the thermistor is shorted or the wiring is damaged, the error will reappear as soon as the next cycle begins. A reset alone is not a fix and should only be used as part of the diagnostic process.

Some causes of F12 are DIY-accessible, such as inspecting and cleaning corroded connector pins or checking wiring for visible damage. Replacing the NTC thermistor is a straightforward repair for someone comfortable working inside an appliance. However, if the control board itself has failed, replacement requires more technical confidence and a higher parts investment.

If only the temperature sensor needs replacement, parts typically cost in the range of $15 to $50 depending on availability. A professional diagnostic visit and labor can add $80 to $150 or more. If the control board is the root cause, parts alone can range from $100 to $250, making total repair costs significantly higher.