BoilerFaultCodesTechnical description
Water filling error - check water pressure sensor.
What causes this fault?
This fault occurs when the boiler's internal computer is unable to detect a stable reading from the water pressure sensor, which is essential for safe operation. The most common reason is that the system water level has dropped too low, but it can also be triggered if the sensor itself has become blocked with debris or has failed electronically.
This fault is more common in autumn when homeowners turn their heating back on for the first time, as small leaks over the summer may have caused the system pressure to drop.
Engineer required
This is a high severity fault. Stop using the boiler and call a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
Find a Gas Safe engineer
Search the official register →