Your boiler is operating normally and is currently in the process of starting up the burner to provide heat or hot 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: Burner ignited
What causes this fault?
This is not a fault, but rather a status message indicating that the boiler has successfully lit the flame. It confirms that the internal ignition sequence is complete and the unit is now producing heat for your radiators or hot water. You will see this code every time the boiler starts up as part of its normal, healthy operation.
DIY fix possible
This fault may be fixable without an engineer. Check your manual first.
Find a Gas Safe engineer
Search the official register for a qualified engineer in your area.
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A boiler cover plan would cover faults like S.4 — no call-out fees, no surprises.
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