BoilerFaultCodesTechnical description
fan overrun
What causes this fault?
This occurs when the boiler’s fan continues to run after the burner has switched off to safely purge remaining heat and combustion gases from the unit. It is a normal safety process that typically happens after a period of intense heating or hot water demand to ensure the internal components cool down correctly. Your boiler hasn't broken down; it is simply finishing its work cycle before it can start again.
DIY fix possible
Wait for 5-10 minutes to allow the cooling cycle to completeEnsure your thermostat is not calling for heat if you want the fan to stop soonerCheck that the boiler display changes to a different code after the cooling period
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