BoilerFaultCodesHeatline F22 Fault Code
The Heatline F22 fault code means: your boiler has stopped working because the water pressure inside the heating system has dropped too low.. It appears on 8 Heatline models in our database.
Technical description: Water pressure of the installation (<0.3 bar)
DIY fix possible
Locate the filling loop (a silver flexible hose) underneath the boiler.Open the small valve or tap on the loop to allow mains water into the boiler.Monitor the pressure gauge on the front until it reaches 1.5 bar, then turn the valve firmly off.
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Heatline models that show the F22 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Heatline F22 fault code information on this page is sourced and cross-checked against the official Heatline service / installation manuals for each affected model.
- Heatline CaprizPlus 28 manual (PDF)
- Heatline CaprizPlus 24a manual (PDF)
- Heatline Compact 24 manual (PDF)
Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 7 July 2026