BoilerFaultCodesTechnical description
No communication between controller and gas valve – controller not connected or valve damaged
What causes this fault?
This fault occurs when the boiler's main control board loses its electronic link with the gas valve, which acts as the engine's fuel pump. Without this constant digital handshake, the boiler cannot safely release gas to create a flame, so it shuts down as a safety precaution. The most common reason is a loose internal connection or a specific electronic failure within the gas valve itself.
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 →