Your boiler’s main computer chip has forgotten its settings or has developed an internal electrical failure, meaning the unit cannot function.

PCB UNCONFIGURED OR FAULTY

What causes this fault?

This fault occurs when the boiler's main control board loses its identity or suffers an internal electrical memory failure. Essentially, the 'brain' of the unit has either corrupted its software settings or the physical circuitry has worn out, preventing it from safely controlling the heating process.