BoilerFaultCodesTechnical description
Fan overrun
What causes this fault?
This scenario occurs when the boiler's internal computer keeps the fan spinning after the burner has turned off to clear away residual heat and combustion gases. While it is often just a normal part of the cooling process, it can also happen if the system detects that temperatures inside the unit are staying high for longer than they should. In rare cases, it may indicate that the control board is misreading signals from the fan.
DIY fix possible
No action required; this is a status code, not a faultAllow the boiler to complete its cooling cycleMonitor only if the fan runs indefinitely without the boiler firing
Find a Gas Safe engineer
Search the official register →