Your boiler's main internal computer has detected a technical error and has stopped working to protect the system.

internal fault

What causes this fault?

This fault occurs when the boiler's main control board suffers an internal electronic failure or a communication error between its components. It is often caused by a power surge, moisture getting onto the circuitry, or simply the electrical components wearing out over time. Because the 'brain' of the boiler can no longer safely manage the heating process, it shuts the system down as a precaution.