F15 High

Saunier Duval F15 Fault Code

The Saunier Duval F15 fault code means: your boiler is having trouble moving an internal valve that controls how hot water is sent to your taps or radiators, meaning it cannot properly switch between heating your home and your hot water supply.. It appears on 4 Saunier Duval models in our database.

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: Stepper motor fault
Typical repair cost £180-280 (including labour)

Engineer required

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

Find a Gas Safe engineer

Search the official register for a qualified engineer in your area.

Gas Safe Register →

Saunier Duval models that show the F15 fault code

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

Source

Saunier Duval F15 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