Your boiler's computer control board has developed an internal electrical fault and is unable to communicate properly with the system.

Internal failure - electronic

What causes this fault?

This fault occurs when the boiler's internal computer brain suffers a hardware failure or a breakdown in its electrical circuitry. The most common reason is age-related wear on the circuit board's components or a sudden voltage spike that has damaged the delicate electronics, preventing the boiler from sending signals to the burner or pump.