Miele Washer Error Code F4024

The F4024 error code on a Miele washer indicates that the control board is reading an impermissibly high resistance or voltage value from the NTC (Negative Temperature Coefficient) thermistor responsible for monitoring water or drum temperature. NTC sensors work by decreasing their electrical resistance as temperature rises. When the circuit is open, meaning the sensor or its wiring has a break, the control module receives a signal that reads as an extremely high resistance value, which the firmware interprets as an out-of-range condition and triggers this fault code.

An open circuit in the NTC sensor circuit is most commonly caused by a physically failed thermistor, a broken or corroded wire in the sensor harness, or a disconnected connector. Because the sensor is exposed to the thermal and mechanical stresses of the wash environment, the sensor element itself can fail internally, breaking the electrical path even when it appears undamaged externally. Connector corrosion or pin-back at the harness connectors can also interrupt continuity without any visible wire damage.

Diagnosing this fault requires isolating whether the fault originates at the sensor itself or in the wiring between the sensor and the control board. A multimeter check of the NTC sensor resistance at room temperature will confirm sensor integrity, as a good NTC thermistor should show a finite, measurable resistance rather than an open-circuit reading (OL or infinite). Continuity testing along the full length of the sensor harness, including all connector points, should follow if the sensor tests within spec.