LED5 flashing Your boiler has switched itself off because the water pressure in your heating system has dropped too low to operate safely.
Your boiler has switched itself off because the water pressure in your heating system has dropped too low to operate safely.
What to check first
- Locate the filling loop (usually a silver flexible hose) underneath or near the boiler.
- Open the filling loop valves slowly until you hear water flowing and watch the pressure gauge.
- Close both valves tightly once the pressure gauge reaches between 1 and 1.5 bar.
Parts commonly replaced
- Filling loop
- Expansion vessel re-pressurisation
- Pressure sensor