BoilerFaultCodesTechnical description
pump overrun
What causes this fault?
This status occurs when the boiler finishes a heating or hot water cycle and needs to dissipate residual heat from the internal components. The pump continues to circulate water briefly to prevent the heat exchanger from overheating or suffering thermal stress once the burner has switched off. It is a programmed safety feature rather than a mechanical failure.
This code is more frequently seen during winter when the heating is used heavily, as the boiler reaches higher temperatures and requires more frequent cooling cycles.
DIY fix possible
Wait for the boiler to complete its cooling cycle, as this code is often a normal operational status rather than a faultCheck that all radiator valves (TRVs) are not fully closed, which can cause heat to build upEnsure the boiler pressure is between 1.0 and 1.5 bar on the front display