BoilerFaultCodesYour boiler is currently going through its normal starting sequence to begin heating your water.
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.
Technical description: Fan start
What causes this fault?
This is a normal operational status that occurs when your boiler prepares to provide heat or hot water. It means the internal fan is spinning up to the correct speed to ensure there is enough air for the combustion process to begin safely. Once the fan reaches the required speed, the boiler will proceed to the next stage of ignition.
DIY fix possible
This fault may be fixable without an engineer. Check your manual first.
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A boiler cover plan would cover faults like S.21 — no call-out fees, no surprises.
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