Your boiler has lost the ability to monitor its own water pressure, meaning it has shut down as a safety precaution.

Pressure sensor fault

What causes this fault?

This fault occurs when the internal sensor responsible for monitoring water levels becomes blocked with debris or suffers an electrical failure. Over time, sludge in the heating system can coat the sensor's delicate diaphragm, preventing it from sending a clear signal to the main control board. Without this vital data, the boiler cannot confirm it has enough water to operate safely and will shut down to prevent overheating.