BoilerFaultCodesMain 119 Fault Code
The Main 119 fault code means: your boiler has stopped working because the water pressure in the central heating system has dropped too low to operate safely.. It appears on 1 Main model in our database.
Technical description: System pressure too low
DIY fix possible
Locate the filling loop (a flexible silver hose) underneath or near the boiler.Open the one or two small taps on the filling loop until you hear water entering the system.Watch the pressure gauge and close the taps once the needle reaches between 1.0 and 1.5 bar.
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Main models that show the 119 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Main 119 fault code information on this page is sourced and cross-checked against the official Main service / installation manuals for each affected model.
Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 7 July 2026