Medium
A4 on Viessmann Vitodens 242-F B2UA

Your boiler has detected that the water pressure inside your heating system has become too high, which can put unnecessary strain on the internal components.

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

Max. system pressure exceeded

From this model's manual
Verified against the Viessmann Vitodens 242 F B2ua installation & service manual, page 128.
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 release a small amount of water until the pressure gauge on the front of the boiler returns to the recommended range, usually between 1.0 and 1.5 bar.

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Related fault codes

A3View →F1View →

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