Your boiler has detected a problem with its internal temperature sensor, which means it cannot safely monitor the water temperature and has stopped working to prevent damage.

Sensor fault S0.

What causes this fault?

This fault occurs when the boiler's main temperature sensor sends an incorrect or missing signal to the control board. The most common reason is that the sensor itself has developed an internal electrical failure, but it can also be caused by loose wiring or water damage on the sensor's connection points.