Your boiler is temporarily running the pump to cool itself down after a period of activity, which is a normal operation rather than a fault.

Pump over run

What causes this fault?

This status occurs when the boiler has finished heating and needs to circulate water to dissipate residual heat from the internal heat exchanger. It is a protective measure to ensure the internal components do not overheat once the burners have turned off. The boiler is simply 'catching its breath' after a period of work and will return to normal operation shortly.