BoilerFaultCodesTechnical description
The filling pressure falls below 0.05 MPa (0.5 bar) and the product switches off.
What causes this fault?
This fault occurs when the water pressure inside your heating system drops below a safe working level, causing the boiler to shut down to prevent internal damage. The most common reason is a slow leak from a radiator valve or pipework, though it can also happen if you have recently bled your radiators and haven't topped the pressure back up.
This code is frequently seen at the start of autumn when homeowners turn their heating back on for the first time after summer, revealing pressure losses that occurred while the system was idle.
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.