How much does it cost to fix Saunier Duval error code F1 or F4?

Typical repair cost for the Saunier Duval F1 or F4 fault is £150-350 including labour.

F1 or F4 High

Saunier Duval F1 or F4 Fault Code

Q: What does the Saunier Duval F1 or F4 fault code mean?

Your boiler is failing to light the internal flame needed to produce heat and hot water despite several attempts.

Also written as F1ORF4 — same fault.

The Saunier Duval F1 or F4 fault code means: your boiler is failing to light the internal flame needed to produce heat and hot water despite several attempts.. It appears on 2 Saunier Duval models in our database.

Technical description: Ignition fault

Typical repair cost £150-350 (including labour)

Engineer required

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

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Saunier Duval models that show the F1 or F4 fault code

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

Source

Saunier Duval F1 or F4 fault code information on this page is sourced and cross-checked against the official Saunier Duval service / installation manuals for each affected model.

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