Emergency
15 on Saunier Duval Isofast F28E

Your boiler has detected a problem with the internal mechanism that controls the gas supply, meaning it cannot safely start up or maintain a flame.

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 mechanism fault

From this model's manual
Verified against the Saunier Duval Isofast F28e installation & service manual, page 30.
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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