Low
S.03 on Vaillant ecoTEC Pro 30

Your boiler is currently trying to light the flame to start your heating, but it is taking a few moments longer than usual to ignite.

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

Heating mode: Ignition

DIY fix possible

Observe the boiler to see if it transitions to code S.04 (Heating mode: Burner ignited)Check that your gas supply is active and turned on at the meterMonitor for any lockout fault codes like F.28 if it fails to ignite

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Related fault codes

F.28View →F.29View →

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