Medium
D.174 on Vaillant ecoTEC plus System

Your boiler has detected that the water pressure inside your heating system is too high for safe operation.

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

Maximumpressurelevel

From this model's manual
Verified against the Vaillant Ecotec Plus installation & service manual, page 78.
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

Locate a radiator in your home with a bleed valvePlace a cloth or small container under the valve and slowly open it with a radiator keyRelease a small amount of water until the pressure gauge on the boiler drops back into the green zone (usually 1.0 to 1.5 bar)Close the valve securely

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