Fixing Boiler Pressure due leaking water from Pressure Relief Valve

If the water has been removed by pumping up the Pressure Vessel and bolier is still going down, then check pipe for Pressure Relief Valve (PRV this is the safety valve to take out when too much water in system especially as it expands on heating due to the closed water circut of the heating system). If dripping then the valve needs to be either cleaned out or replaced as per the video. Good luck.