High
All Boilers on Glow-worm HXi

Your boiler has failed to ignite and cannot produce heat, which is usually due to an interrupted gas supply, a blocked condensate pipe, or a component failure.

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.

Technical description

F28 / F1 / F4

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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