Emergency
L.E.D. H (Yellow) on Ariston Challenger 80E

Your boiler has detected an issue with venting its waste gases and has safely turned itself off to prevent carbon monoxide buildup.

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

EXHAUST DISCHARGE ANOMALY SHUTDOWN: The boiler is fitted with safety devices, which in the event of defective discharge of exhaust products, automatically interrupts the gas supply. Shutdown is temporary (approx 15 minutes).

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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