Low
S.11 on Vaillant ecoTEC plus System

Your boiler is simply performing a routine safety check by clearing its internal ventilation before it begins heating your water.

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

Hot water handling mode: Advance fan operation

Engineer required

This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.

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Related fault codes

S.10View →

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