High
Flashing 0.3 bar on Glow-worm Xtramax HE

Your boiler’s water levels have dropped too low for it to start up safely.

Call an engineer soon

Book a Gas Safe engineer within 24 to 48 hours. Your boiler may be unsafe or could break down completely if left.

What the manual says

Manufacturer manual

Insufficient system pressure - the system pressure is low

From this model's manual
Verified against the Xtramax 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.

What causes this fault?

This fault occurs when the water pressure inside your central heating system drops below the minimum level required for the boiler to operate. The most common reasons for this are a leak somewhere in the pipework or radiators, or the air pressure in the expansion vessel needing to be topped up by an engineer.

This issue is more frequent in autumn when people turn their heating back on after summer, as the change in temperature can highlight minor leaks or a loss of pressure in the system.

Engineer required

This is a high severity fault. Stop using the boiler and call a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.

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