Medium
E40 on Keston C36p

Your boiler has detected that there is too much water inside your heating system, which is causing excess pressure.

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 too high - You have put too much water pressure in your system

From this model's manual
Verified against the Keston C36p installation & service manual, page 32.
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, preferably one upstairs.Use a radiator bleed key to gently open the bleed valve.Release a small amount of water into a cloth or container until the pressure gauge on the boiler front drops to between 1 and 1.5 bar.Close the valve and check the boiler display to see if the error clears.

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