BoilerFaultCodesWhat the manual says
Manufacturer manualFan over run (hot water operation)
What causes this fault?
This occurs when the internal temperature sensors detect that the heat exchanger is still very hot after the boiler has finished heating your water. To prevent heat damage to sensitive internal components, the boiler keeps the fan running to pull cool air through the unit and dissipate the excess heat. It is a normal safety function, though it can sometimes indicate that the system is struggling to shed heat quickly enough due to a buildup of debris.
This status is more common during the summer months when the ambient air temperature is higher, making it take longer for the boiler to cool down naturally.
DIY fix possible
Check that your room thermostat or programmer is set correctlyEnsure at least one radiator valve is fully open to allow heat to dissipateMonitor the display to see if the status code changes to a normal standby mode after a few minutes
Avoid the next call-out bill
A cover plan would handle faults like S.16: no call-out fees, no surprise bills.
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