How much does it cost to fix Saunier Duval error code F26?

Typical repair cost for the Saunier Duval F26 fault is £180-350 including labour.

F26 High

Saunier Duval F26 Fault Code

Q: What does the Saunier Duval F26 fault code mean?

Your boiler has detected that the water is heating up or cooling down far too quickly, which usually indicates that the internal pump is failing to move the water around the system properly.

The Saunier Duval F26 fault code means: your boiler has detected that the water is heating up or cooling down far too quickly, which usually indicates that the internal pump is failing to move the water around the system properly.. It appears on 3 Saunier Duval models in our database.

Technical description: Maximum delta temperature

Typical repair cost £180-350 (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 F26 fault code

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

Source

Saunier Duval F26 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 31 August 2026