BoilerFaultCodesSaunier Duval F17 Fault Code
The Saunier Duval F17 fault code means: your boiler has stopped working because the electrical power coming from your home's mains supply is too low for it to run safely.. It appears on 5 Saunier Duval models in our database.
Technical description: Power supply is less than 170V
What causes the Saunier Duval F17 fault?
This fault occurs when the electrical voltage entering the boiler drops to a level that is too low for the internal components to function. This is usually caused by a broader issue with the local power grid or an electrical fault within your home's wiring. In some cases, a failing internal circuit board can mimic this error by incorrectly reading the incoming power.
This fault can be more common during periods of extreme cold or high grid demand when the local electrical network is under significant strain.
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
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Gas Safe Register →Saunier Duval models that show the F17 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Saunier Duval F17 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