Bosch Washer Error Code NTC interruption

The NTC interruption error on a Bosch washer indicates that the NTC (Negative Temperature Coefficient) thermistor, which is the water temperature sensor, has developed an open circuit condition. An NTC thermistor works by changing its electrical resistance in response to temperature. Under normal operation, the control board reads a specific resistance value from the sensor to determine water temperature and regulate heating accordingly. When the circuit is interrupted or open, no resistance signal reaches the control board, and the machine cannot safely manage the heating cycle.

This fault is specifically detected during the Bosch test programme, which cycles through key components and checks for expected electrical responses. An open circuit in the NTC path means the control board receives no signal at all, as opposed to a short circuit which would return an abnormally low resistance reading. The interruption can originate at the sensor itself, in the wiring harness connecting it to the control board, or at the connector terminals.

The most common cause is a failed NTC thermistor where the internal element has physically broken, permanently opening the circuit. Corroded or loose connector pins and damaged wiring are also frequent contributors, particularly in machines with age-related wear. Because the washer cannot monitor water temperature without a functioning NTC, it will halt operation to prevent overheating or damage to the drum, heater element, or laundry.