BoilerFaultCodesJohnson Starley LOW WATER PRESSURE Fault Code
Also written as LOWWATERPRESSURE — same fault.
The Johnson Starley LOW WATER PRESSURE fault code means: your boiler has stopped working because the amount of water inside your heating system has dropped below the necessary level to operate safely.. It appears on 1 Johnson Starley model in our database.
Technical description: System pressure below required range or faulty pressure sensor
DIY fix possible
Locate the external filling loop, which is usually a silver braided hose with one or two valves located underneath your boiler.Gradually open the valve(s) to allow mains water into the system until the pressure gauge on the front of the boiler reads between 1.0 and 1.5 bar.Close the valve(s) tightly and check for any leaks around the connection points.
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Johnson Starley models that show the LOW WATER PRESSURE fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Johnson Starley LOW WATER PRESSURE fault code information on this page is sourced and cross-checked against the official Johnson Starley service / installation manuals for each affected model.
Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 7 July 2026