Bosch Washer Error Code NTC short circuit

The NTC short circuit error on a Bosch washer indicates that the NTC thermistor, which is the temperature sensor responsible for monitoring water temperature during wash cycles, has developed a short circuit condition. This fault is specifically detected during the test programme, which runs a series of checks on key electrical components. The NTC thermistor is a negative temperature coefficient resistor, meaning its resistance decreases as temperature rises. A short circuit causes the sensor to report an abnormally low resistance value, which the control board interprets as an implausibly high temperature reading or an outright sensor failure.

The most direct cause of this fault is internal failure of the NTC thermistor itself, where the sensor element shorts internally due to age, heat stress, or moisture intrusion. The sensor is typically mounted in the sump area or heating element assembly, where it is exposed to water and thermal cycling over thousands of wash cycles. Wiring harness damage between the NTC and the control board can also produce a short circuit reading, particularly if insulation has worn through and conductors are making contact with each other or with a grounded surface.

Diagnosing this fault requires running the Bosch test programme to confirm the short circuit is active and repeatable. If the fault is confirmed, the NTC thermistor should be tested with a multimeter to check for abnormally low or zero resistance across its terminals. A healthy NTC will show measurable resistance that changes with temperature. A reading near zero ohms at room temperature confirms a short circuit and means the sensor requires replacement.