BoilerFaultCodesHeatline Bar LED Flashing Fault Code
Also written as BARLEDFLASHING — same fault.
The Heatline Bar LED Flashing fault code means: your boiler has stopped working because the water pressure inside the heating system has dropped too low.. It appears on 1 Heatline model in our database.
Technical description: Low water pressure (Check pressure gauge show >1 bar / Repressurise system)
DIY fix possible
Locate the filling loop, which is a silver braided hose with one or two valves underneath your boiler.Open the valve(s) slowly to let water into the system until the pressure gauge needle on the front of the boiler reaches between 1 and 1.5 bar.Close the valve(s) tightly and the boiler should automatically restart.
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Heatline models that show the Bar LED Flashing fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Heatline Bar LED Flashing fault code information on this page is sourced and cross-checked against the official Heatline service / installation manuals for each affected model.
Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 7 July 2026