Air in central heating system

[tadders]

I am getting air in my heating system even when it is not in use. I can hear a slight air noise from the rad nearest to the pump. This rad is not leaking water. Also when I switch the water heater on I can hear air/water in the heating pipes moving. Any ideas please?

 

[kevplumb]

boiler / system ???

have you tryed bleeding the rad/s

 

[Beerlover]

Could be pumping over/sucking down - would indicate circulation problems and a powerflush may help.

Get several quotes/inspections.

 

[tadders]

thanks for the replies. Yes I have bled the rads, as mentioned the only one that needs bleeding is the one closet to the pump. If I don't use the system for water or heating, system turned off, it still gets air in the rad? If I'm not using it, how is this happening?

 

[twgas]

might be gassing, which is caused by corrossion, another sign of a powerflush being needed and possibly pipework alterations.