High
F1, F4 on Saunier Duval Isotwin F30E

Your boiler is trying to start but the flame is failing to ignite, meaning you currently have no heating or hot water.

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.

Technical description

Ignition fault, boiler fialed to light. No gas / Insufficient gas. Incorrect gas valve adjustment. Electrode ignition lead defect. Electrnic igniter defective. Check air inlet duct and connections to igniter unit

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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Related fault codes

F1View →F4View →

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