Your boiler's computer has lost its internal configuration settings, meaning it has forgotten how to operate correctly.

wrong parameter from the factory

What causes this fault?

This fault occurs when the boiler's internal computer system loses track of the fan's speed or the air flow required for safe combustion. It is often caused by a buildup of dust in the fan assembly or a loose electrical connection that disrupts the signal between the components. While it may start as an intermittent glitch, it usually points to a mechanical part that is beginning to fail.