BoilerFaultCodesPotterton Low system pressure Fault Code
Also written as LOWSYSTEMPRESSURE — same fault.
The Potterton Low system pressure fault code means: your central heating system has lost the water pressure it needs to circulate heat, which will prevent the boiler from running until it is topped back up.. It appears on 2 Potterton models in our database.
Technical description: System pressure is less than 0.5 bar. Pressurise the system to 1.5 bar.
DIY fix possible
Locate the filling loop (usually a silver flexible hose) underneath the boiler or near the heating pipes.Open the valves at both ends of the hose to let mains water into the system.Monitor the pressure gauge on the front of the boiler until the needle reaches 1.5 bar, then securely close both valves.
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Gas Safe Register →Potterton models that show the Low system pressure fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Potterton Low system pressure fault code information on this page is sourced and cross-checked against the official Potterton service / installation manuals for each affected model.
Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 27 April 2026