After bleeding my radiators as a few of them were cold at the top, the water pressure on my boiler has dropped into the red area! It only has about 0.5bar of pressure, and drops to 0 if my heating is switched down for a few hours. Before i bled them the water pressure was around 1 bar before the heating was called for! I have been told that there should be a black tap underneath but fail to find it! Could anyone help in locating the exact area for this as the tap may have come off or been removed!

Richard James, January 2009