I flushed down central heating system and the system works.However I noticed water dripping from the header tank when the system is on .There donot seem to be any air lock all the radiators are working well without any noise.I have also reduced the boiler temperature.Help and suggestion will be appreciated.System is open and gravity fed with Baxi back boiler.Hot water flow is normal as well.though the shower need to be flushed to let air out before hot water flows which was happening before anyway.[/b]