E20 Emergency

Ariston E20 Fault Code

The Ariston E20 fault code means: your boiler has detected a flame signal even though it is trying to turn the gas off, which indicates a serious safety issue with the internal control system.. It appears on 6 Ariston models in our database.

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: Flame detected with gas valve closed
Typical repair cost £150-300 (including labour)

Engineer required

This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.

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Ariston models that show the E20 fault code

Click a model for the full fault code list and model-specific repair notes.

Source

Ariston E20 fault code information on this page is sourced and cross-checked against the official Ariston service / installation manuals for each affected model.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 27 April 2026