My shower works ok when there is no heating on. If i put the heating on then the pressure goes up and up , so i have to bleed a radiator until the pressure is really low, it then stabilizes. The problem then is if i try to put the shower on , it won't fire up.I changed the loop filler recently as we thought that the pressure was coming from the cold water filler. But the problem is still there.
if it only rises with heating on, expansion vessel, if it rises any time even with heating off, passing filling loop or pin holed heat exchanger..usually
