Emergency
E 20 on Ariston Genus

Your boiler is confused and thinks there is a flame inside while the gas supply is already switched off, which has caused it to shut down for safety.

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

False flame detection with gas valve closed

From this model's manual
Verified against the Ariston Genus One 24 installation & service manual, page 45.
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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