Emergency
F16 on Glow-worm Flexicom CXi

Your boiler has detected that a flame is still burning inside even though it has commanded the system to turn off, which means it has safely shut itself down to prevent a hazard.

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

Flame detection fault (flame presence for more than 5 seconds after burner stop)

From this model's manual
Verified against the Glow Worm Flexicom Cxi installation & service manual, page 39.
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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