Your boiler is performing a routine self-cleaning cycle to prevent internal parts from getting stuck during periods of inactivity.

Anti-seizing functn. active

What causes this fault?

This occurs when the boiler has been sitting idle for a long period without a request for heating or hot water. To prevent the internal pump and diverter valve from seizing up due to inactivity, the system automatically triggers a brief movement cycle to keep all mechanical components lubricated and moving freely.