BoilerFaultCodesWhat the manual says
Manufacturer manualpump / fan overrun
From this model's manual
Verified against the Glow Worm Ultracom 2 Sxi installation & service manual, page 55.
What causes this fault?
This occurs because the boiler needs to dissipate residual heat from the internal heat exchanger after it has finished heating your water or radiators. The pump and fan continue to run briefly to ensure the unit stays within safe temperature limits before it enters standby mode. It is a standard protective measure rather than a breakdown of any internal components.
DIY fix possible
Wait up to 15 minutes for the cycle to complete naturallyCheck that your room thermostat is turned downEnsure at least one radiator valve is fully open to allow water to circulate
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