BoilerFaultCodesTechnical description
Internal error
What causes this fault?
This fault occurs when the boiler’s main control board experiences a communication failure or an internal electronic processing error. It is essentially a breakdown in the boiler's 'brain' where it can no longer send or receive correct signals to operate the heating components safely. The most common reason is electronic component fatigue over time or a loose connection in the internal wiring loom.
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 →