Low
S.03 on Vaillant aquaPLUS

Your boiler is currently trying to light the flame to start your central heating.

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.

Technical description

Ignition sequence (heating operation)

DIY fix possible

Check if your thermostat is calling for heatWait a few minutes to see if the boiler transitions to a run codeEnsure your gas supply is turned on if the boiler fails to light

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Related fault codes

S.01View →S.02View →F.28View →F.29View →

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