BoilerFaultCodesKeston Low water pressure Fault Code
Also written as LOWWATERPRESSURE — same fault.
The Keston Low water pressure fault code means: your boiler has detected that there is not enough water in the system to operate safely, which is usually caused by a small leak or air being bled from radiators.. It appears on 5 Keston models in our database.
Technical description: Low water pressure
DIY fix possible
Locate the filling loop (usually a silver flexible hose) underneath or near the boiler.Slowly open the one or two taps/valves until you hear water flowing.Watch the pressure gauge until it reaches between 1.0 and 1.5 bar, then close the taps tightly.
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Keston models that show the Low water pressure fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Keston Low water pressure fault code information on this page is sourced and cross-checked against the official Keston service / installation manuals for each affected model.
Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 7 July 2026