Emergency
2.5 bar or above on Glow-worm 23c

Your boiler pressure is too high, which puts unnecessary stress on the internal system components.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

Act immediately

Turn off your boiler and stop using gas appliances. Call a Gas Safe engineer now. This fault can be dangerous if ignored.

What the manual says

Manufacturer manual

Over pressure, the fault display (b) will flash. The pressure must be reduced to 1.5 bar by bleeding a radiator.

From this model's manual
Verified against the Glow Worm 23c installation & service manual.
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 is a emergency severity fault. Stop using the boiler and call a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.

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Boiler cover options

Avoid the next call-out bill

A cover plan would handle faults like 2.5 bar or above: no call-out fees, no surprise bills.

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