Your boiler is currently reporting that the water pressure inside the system is too low to operate your hot water and heating safely.

DIY fix possible

Locate the filling loop (a flexible metal or plastic pipe) underneath the boiler.Slowly open the valves on the filling loop to allow cold mains water into the system.Watch the pressure gauge on the front of the boiler until it reaches the green zone, typically between 1.0 and 1.5 bar.Close both valves tightly and ensure the filling loop is fully shut off.