Low
S.034 on Vaillant ecoTEC plus System

Your boiler is temporarily running its pump to prevent the water inside from freezing during cold weather.

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.

What the manual says

Manufacturer manual

The frost protection function is active.

From this model's manual
Verified against the Vaillant Ecotec Plus installation & service manual.
Plain-English guidance below. Severity, DIY steps, costs and parts are our interpretation to help you act, not text from the manual.

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.030View →S.031View →

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