Medium
S.52 on Vaillant ecoTEC Pro / ecoTEC Plus

Your boiler has detected that the internal water pressure is too high, which can cause it to stop working to protect the system from damage.

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 > 2,9 bar

From this model's manual
Verified against the Vaillant Ecotec Combi installation & service manual, page 43.
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 that has a bleed valve.Place a cloth or small container under the valve.Open the valve slightly to let a little water out until the pressure gauge on the front of the boiler drops to between 1.0 and 1.5 bar.Close the valve tightly.

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