Low
S.04 on Vaillant ecoTEC plus System

Your boiler is operating exactly as it should and is currently actively heating your radiators.

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

Display shows S.04 if the product is working correctly in heating mode.

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.02View →S.03View →

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