air in hot water taps!

[ih]

hi all
Intermittently am having air in hot water taps. some days it is ok and others not. In the past 2 weeks have have emptied the hot water cylinder
but the problem has not gone away.my system is conventional boiler with indirect copper cylinder with central heating header tank and large cold water tank. thanks in advance for help/advise
ih
ps. have also checked when hot water tap is open the cold water tank is filling up have also checked the ball valve in the tank and is working![/list]

 

[Onetap]

Probably air being sucked into the open vent pipe.
Is it a recent problem or has it been happening for a long time?
Does it happen at low water flow rates, or just start when the bath taps are nearly fully open?

Are there any isolating valves on the tank outlet or cylinder cold feed &, if so, are they fully open?

 

[easyflow]

Partial blockage between the domestic tank and cylinder caused by scale or debris, could be the sacrificial anode is exhausted and scaled not allowing good flow of water into the cylinder from the domestic tank.
How old is your system ?

 

[ih]

thanks for the reply.
The system is 12 year old. the house has a water softner also. the problem is recent started this year it mostly starts happening when taps are qtr turned. all the gate valves and taps isolating i have double checked and all are open. If it is the vent pipe then i dont know if so how do i rectify or check if that is the case.
ih