High
F4 on Saunier Duval SD Themaplus Condens F 30 E

Your boiler has stopped working because it is failing to ignite and cannot detect a flame, 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.

What the manual says

Manufacturer manual

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

From this model's manual
Verified against the Saunier Duval/Saunier Duval Themaplus Condens F30e 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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Related fault codes

F28View →F29View →

All 18 fault codes on the SD Themaplus Condens F 30 E

Seeing a different code? Every code this model can display, in one place.

F1F5F6F7F8F9F10F11F13F16F18F19F20F23F26F28F29

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