Low
S.11 on Heatline Compact 30

Your boiler is currently preparing to ignite, but the internal fan is checking its position before the system starts burning fuel.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

Monitor it

This is a minor fault. Keep an eye on it and mention it at your next annual boiler service. Reset the boiler and see if it clears.

What the manual says

Manufacturer manual

Pre-run fan

Shared across the range
This code is shared by the boilers in this range, which use the same control board. It may not be printed in this exact variant’s manual.
Plain-English guidance below. Severity, DIY steps, costs and parts are our interpretation to help you act, not text from the manual.

DIY fix possible

No action required; this is a normal status messageWait for the boiler to complete its pre-ignition checksMonitor for any persistent error codes if the fan fails to start

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