Your boiler's internal computer brain either isn't set up correctly or has developed a technical hardware fault, preventing the unit from starting.

PCB UNCONFIGURED OR FAULTY

What causes this fault?

This fault occurs when the boiler's main control board has lost its identity and no longer knows which specific model it is supposed to be operating. The most common reason is a technical communication failure between the internal computer chip and the plug-in hardware key that stores the boiler's settings.