Your boiler's computer brain has malfunctioned and can no longer control the heating system safely.

Control box failure

What causes this fault?

This fault occurs when the internal circuit board, which acts as the boiler's brain, suffers a critical electronic failure or loses its memory. The most common reasons are age-related wear to the electrical components or a power surge that has damaged the delicate circuitry. Because the board can no longer safely monitor the gas valve or sensors, it shuts the system down to prevent an accident.