Gravity feed hot water

[abacas]

I have just moved into a bungalow which had some plumbing problems.Most of these were related to leaky joints.The system is powered by a Vaillant boiler plumbed to a pressurised heating circuit and a gravity feed hotwater system which I would guess is about 15 years old.The problem I am having is very low pressure ( a dribble) on the hot water both Kitchen and bathroom (bathroom worst).The header tank has a 12 foot head. It seems that there is air in the system. I remember some years ago I had this happen and I back filled the system from a tap and it cleared the issue. Now a bit older are there any dangers in going down this route or is there an easier option?

 

[justlead1]

Hi. This statment is a bit confussing "The system is powered by a Vaillant boiler plumbed to a pressurised heating circuit and a gravity feed hotwater system" However air locks can be cleared by the method you mention. But i could also be fitting dezincing or corrosion. Try the air lock exercise first. Good Luck