I've just had my radiators power flushed and now I keep getting loads of air in the system - 2 rads in particular are about half full of air each day. Any ideas how so much air is getting in and what I can do to fix it? It's an open vented system.
If you keep getting this problem it is worth checking that your circulating pump has not been set to a higher level. Go to your header tank when your system is running and make sure that the suction of the pump is not causing a vortex and dragging air into the system.