Air in radiators

[jager]

i have a WILO GOLD 50 pump, NYSON power extractor, SANTON premier cylinder and a POTTERTON suprima boiler and i have a small blue circular tank coming off the cylinder which i think is a pressure tank.

I have been getting a lot of air in the radiators as i am also unable to get any hot water.

I have bled the radiators and the cylinder and i have checked there is enough water in the header tank in the loft. But i am unable to see where the air is getting in to the system.

Has anybody got any ideas?

 

[jager]

I have just noticed a leak comming from the copper valve that ia attached to the pump.

will i need a new pump or is this replaceable

 

[bones001]

brass valve?? you can replace it without changing the pump yes

 

[jager]

Thanks

Would this leak create the problems i am having?