Your boiler has lost water pressure and needs to be topped up to work at full capacity.

DIY fix possible

Locate the filling loop (a silver flexi-hose) underneath the boiler or near your pipework.Open the valves on the filling loop to allow cold mains water to enter the system.Watch the pressure gauge on the boiler until the needle reaches the green zone (typically 1.2 to 1.5 bar).Close both valves tightly and remove the filling loop if required by your specific model.