Johnson Starley LP Fault Code
The Johnson Starley LP fault code means: your boiler is currently running in a special test mode used by engineers to check its performance and it is not a technical fault.. It appears on 1 Johnson Starley model in our database.
Technical description: Minimum combustion rate (indicating sweep test mode)
DIY fix possible
Wait approximately 15 to 20 minutes for the boiler to automatically exit the test modeTurn the main power switch or boiler dial to the 'Off' positionSwitch the boiler back on to 'Reset' the system to normal operation
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Gas Safe Register →Johnson Starley models that show the LP fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Johnson Starley LP 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 27 April 2026