Glow-worm hxi range Fault Code
Also written as HXIRANGE — same fault.
The Glow-worm hxi range fault code means: your boiler has detected an issue with the water pressure or the sensor that monitors it, preventing the system from heating up safely.. It appears on 3 Glow-worm models in our database.
Technical description: F9
DIY fix possible
Check the pressure gauge on the front of the boiler; it should be between 1.0 and 1.5 bar.If the pressure is below 1.0 bar, use the filling loop underneath the boiler to increase it.Once the pressure is corrected, press the 'Reset' button to restart the boiler.
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Gas Safe Register →Glow-worm models that show the hxi range fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Glow-worm hxi range fault code information on this page is sourced and cross-checked against the official Glow-worm service / installation manuals for each affected model.
Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 27 April 2026