Your boiler has shut down completely because it reached the maximum number of failed attempts to fix an underlying problem.

Final fault code (Refer to section 7.11)

What causes this fault?

This fault occurs when the boiler's internal computer has tried multiple times to resolve a previous error but has failed to do so safely. It acts as a safety shutdown to prevent damage, usually triggered by a persistent issue with the ignition process or the fuel delivery system. Because the boiler cannot confirm it is firing correctly after several attempts, it enters a hard lock to protect the household.