BoilerFaultCodesWhat the manual says
Manufacturer manualFan over run
What causes this fault?
This occurs when the boiler’s internal heat exchanger needs to shed excess heat after you have finished using a hot water tap. The boiler activates the fan to pull cool air through the unit to prevent internal components from getting too hot. It is a standard safety and maintenance process rather than a mechanical failure.
This may be more noticeable in summer when the incoming cold water mains temperature is higher, meaning the boiler has less naturally cold water to help it cool down quickly.
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
Avoid the next call-out bill
A cover plan would handle faults like S.26: no call-out fees, no surprise bills.
Affiliate links. We may earn a commission at no extra cost to you.
Related fault codes
All 77 fault codes on the ecoTEC plus 637
Seeing a different code? Every code this model can display, in one place.