BoilerFaultCodesTechnical description
Water pressure switch error – not operated.
What causes this fault?
This fault occurs when the water pressure inside your heating system drops below a safe level, causing the boiler to shut down to prevent overheating. The most common reason is a small leak in the pipework or radiators, though it can also happen if you have recently bled your radiators and haven't topped the water back up.
This fault is frequent in autumn when homeowners turn their heating back on for the first time or bleed their radiators to prepare for winter.
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 →