Inlet NTC sensor or zero-crossing circuit failure

The inlet NTC (Negative Temperature Coefficient) sensor or the zero-crossing detection circuit has malfunctioned.

The NTC sensor measures incoming water temperature to calibrate heating. It can fail from electrical interference, moisture ingress, or component ageing. The zero-crossing circuit synchronises power delivery to the heater — a failure here can be caused by power supply instability or a faulty control board.

Disconnect the machine from power immediately. This error requires professional diagnosis as it involves internal electrical components. Contact our support team to arrange an inspection and repair.