Emergency
Yellow L.E.D. H illuminated on Ariston Egis 24 MFFI

Your boiler has temporarily turned itself off because it is struggling to safely clear away waste gases, which could lead to harmful fumes building up if not addressed.

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

Temporary Shutdown Due To Defective Discharge of Exhaust Fumes: safety devices automatically interrupt the gas supply due to defective discharge of exhaust products. The shut-off is temporary (approx. 15 minutes).

From this model's manual
Verified against the 617 IntesaTP23 30MFFIInst installation & service manual.
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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