BoilerFaultCodesSaunier Duval F22 Fault Code
The Saunier Duval F22 fault code means: your boiler has detected that the water pressure inside the system has risen too high, causing it to shut down for safety.. It appears on 2 Saunier Duval models in our database.
Technical description: Water pressure too high
DIY fix possible
Locate the external filling loop, which is usually a silver braided hose with one or two valves located underneath the boiler.Ensure both valves are turned completely off, as a passing valve can cause the pressure to creep up over time.If the pressure remains high, bleed a radiator in your home to drain a small amount of water until the pressure gauge returns to the green zone (usually 1 - 1.5 bar).
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Gas Safe Register →Saunier Duval models that show the F22 fault code
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Source
Saunier Duval F22 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