BoilerFaultCodesYour boiler is currently busy performing its normal start-up sequence to fire up the burner for heating.
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: Heatingmode:Burnerignition
What causes this fault?
This code appears when the boiler is transitioning from a standby state to an active heating state. It signifies that the internal components are currently sparking the burner to create a flame, which is a necessary step to start warming your radiators. This is a standard part of the boiler's operation and not an indication of a mechanical failure.
This status is most frequently seen during autumn and winter when the heating system is first called upon to handle colder outdoor temperatures.
DIY fix possible
Check if your thermostat is calling for heatWait a few minutes to see if the status code changes to a running code (starting with 'S.04')Ensure your gas supply is active and credit is on the meter
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A boiler cover plan would cover faults like S.03 — no call-out fees, no surprises.
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