5 (Flashing) Your boiler has stopped working because the water pressure inside the heating system has dropped too low to operate safely.
Your boiler has stopped working because the water pressure inside the heating system has dropped too low to operate safely.
What to check first
- Locate the external filling loop, which is usually a braided silver hose connecting two pipes under the boiler
- Open the small valve or tap on the filling loop to allow cold mains water to enter the system
- Watch the pressure gauge on the front of the boiler and close the valve once the needle reaches 1.5 bar
- Check for any obvious puddles under radiators or the boiler that might explain the initial pressure loss
Parts commonly replaced
- Filling loop
- Pressure relief valve
- Pressure gauge