Medium
S.41 on Glow-worm Ultimate3 System

Your boiler has detected that the water pressure inside the heating system is currently set too high for it to operate safely.

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

From this model's manual
Verified against the Glow Worm Ultimate3 System 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, preferably one upstairs.Using a radiator bleed key, gently open the bleed valve to release a small amount of water into a cloth or container.Check the boiler's pressure gauge until the needle drops into the recommended green zone, usually between 1.0 and 1.5 bar.

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