I have a megaflow system. Last winter when the heating was not on the pressure would fall below 1 bar and then not switch on, I would then add water to the system and it would work fine before going above 3, at which point I would need to take some water out the system. As soon as the weather warmed up the problem stopped and the pressure remained between 1.5 and 2.8 at all times. Now that the temp has dropped the problem has started all over again!!. Anyone with any advice out there??