Medium
S.41 on Vaillant ecoTEC Plus 826

Your boiler's internal water pressure has become too high, which can put unnecessary strain on the system's internal components.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

Book a service

This fault should be looked at by a Gas Safe engineer within the next week or two. It may get worse if left.

What the manual says

Manufacturer manual

Water pressure > 2.8 bar

From this model's manual
Verified against the Vaillant Ecotec Plus 826 installation & service manual, page 48.
Plain-English guidance below. Severity, DIY steps, costs and parts are our interpretation to help you act, not text from the manual.

DIY fix possible

Turn off the boiler and allow it to cool down completely.Locate a radiator in your home, place a cloth underneath the bleed valve, and use a radiator key to slowly release air and water.Monitor the pressure gauge on the boiler front until the needle drops into the green zone, usually between 1.0 and 1.5 bar.

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