BoilerFaultCodesYour boiler is operating normally and is currently in the process of heating your home or 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 mode
What causes this fault?
This is a normal status message indicating that the boiler's burner has successfully ignited and is currently generating heat. It appears when the system is actively responding to a request for central heating or hot water. It is not an error, but rather a confirmation that the combustion process is working exactly as it should.
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.4 — no call-out fees, no surprises.
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