Emergency
16 on Saunier Duval Thelia

Your boiler has detected a problem with the internal mechanism that controls the gas supply, meaning it has shut down to keep your home safe.

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.

Technical description

Gas safety value failure

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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