High
02 on Saunier Duval Ecosy 24E

Your boiler is failing to ignite because it cannot detect a flame, which is often caused by air trapped in the gas supply.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

Call an engineer soon

Book a Gas Safe engineer within 24 to 48 hours. Your boiler may be unsafe or could break down completely if left.

What the manual says

Manufacturer manual

There is no flame ionisation. This fault code may appear on commissioning the boiler and may simply due to the presence of air in the gas line.

From this model's manual
Verified against the Saunier Duval Ecosy 24e 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 high severity fault. Stop using the boiler and call a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.

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