Your boiler has detected an issue with its internal sensors and has stopped running to prevent any damage or incorrect temperature readings.

The diagnostics will indicate the nature of the fault to assist a speedy and effective repair

What causes this fault?

This fault occurs when the boiler's internal sensors stop communicating correctly with the main control board. It is usually caused by an electrical failure within the sensor itself or a loose connection in the wiring that prevents the boiler from safely monitoring water temperature. Because the boiler cannot tell how hot the water is getting, it shuts down as a safety precaution.