Your boiler's internal computer has detected a general electrical communication error and has shut down as a safety precaution.

Boiler electr. system fault

What causes this fault?

This fault occurs when the boiler's main control board loses the ability to talk to the internal sensors and components that manage the heating process. It is typically caused by a loose connection in the internal wiring or a critical failure within the printed circuit board itself, which prevents the boiler from safe operation.