High
Neon 3 lit (NO) on Glow-worm Space Saver 30 40 50

Your boiler has stopped working because it cannot safely clear waste gases, which prevents it from igniting to protect your home.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

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

Air flow proving fault - that is fan or air pressure switch - see detailed fault finding chart.

From this model's manual
Verified against the Space Saver 30 40 50 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 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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Related fault codes

Neon 1View →Neon 2View →

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