Medium
E01 on Potterton Promax 15 & 24

Your boiler has detected that the water pressure in your central 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

Primary pressure too high

From this model's manual
Verified against the Potterton Promax 15 24 installation & service manual, page 39.
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 upstairs or furthest from the boiler.Using a radiator bleed key, slightly open the bleed valve to let a small amount of air and water out, catching the water in a cloth or container.Monitor the boiler's pressure gauge until the needle drops into the green zone, typically between 1.0 and 1.5 bar.

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