Your boiler’s internal computer brain has developed a critical electronic fault and can no longer communicate with the rest of the system.

internal failure - electronic

What causes this fault?

This fault occurs when the boiler's main control board suffers a hardware failure, meaning it can no longer send or receive the signals needed to manage the heating process safely. The most common reason is age-related wear to the delicate electrical circuits on the board, though it can also be triggered by a sudden power surge or moisture getting into the control box.