Emergency
F.62 on Glow-worm Sustain 12s

Your boiler has detected that the gas valve is not closing as quickly as it should, which is a safety feature to prevent unburnt gas from leaking into the system.

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

Gas valve shut-off delay fault

From this model's manual
Verified against the Glow Worm Sustain 12s installation & service manual, page 34.
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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