Medium
2128 on Warmflow 70/90 Combi

Your boiler's internal expansion vessel has lost its air pressure, which means it cannot safely manage the pressure changes in your heating system as it warms up.

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

12 Litre Pressure Vessel

From this model's manual
Verified against the Warmflow 70 90 Combi installation & service manual, page 51.
Plain-English guidance below. Severity, DIY steps, costs and parts are our interpretation to help you act, not text from the manual.

Engineer required

This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.

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Related fault codes

2129View →2130View →

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