BoilerFaultCodesTechnical description
Internal error.
What causes this fault?
This fault occurs when the boiler's main control board experiences a communication error or an internal electronic failure, preventing it from processing safety checks. It is often caused by a sudden power surge, moisture ingress, or simply the age of the electrical components leading to a system crash. Think of it like a computer freezing; the brain of the boiler can no longer send or receive the signals needed to operate safely.
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 →