BoilerFaultCodesHeatline Flashing 80 Fault Code
Also written as FLASHING80 — same fault.
The Heatline Flashing 80 fault code means: your boiler has stopped working because the water pressure inside the heating system has dropped too low to operate safely.. It appears on 2 Heatline models in our database.
Technical description: Low System Pressure
DIY fix possible
Locate the external filling loop, which is usually a flexible silver hose under the boiler connecting two pipes.Open the attached valves slowly to allow mains water into the system until the pressure gauge reads between 1.0 and 1.5 bar.Close both valves tightly and ensure no water is leaking from the connection points.
Find a Gas Safe engineer
Search the official register for a qualified engineer in your area.
Gas Safe Register →Avoid the next call-out bill
A cover plan would handle faults like Flashing 80: no call-out fees, no surprise bills.
Affiliate links. We may earn a commission at no extra cost to you.
Heatline models that show the Flashing 80 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Heatline Flashing 80 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