Technical description
Internal boiler control error
What causes this fault?
This fault occurs when the boiler's main control board suffers a hardware failure and can no longer communicate with the internal sensors. It is usually caused by electrical components on the circuit board wearing out over time or a loose connection in the internal wiring loom. Because the 'brain' of the boiler can no longer monitor safety, it shuts the entire system down as a precaution.
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 →