I just moved to a new house and the CH system is a mess. Two of the radiators are not working, I have looked at the system pipework and the two radiators are connected via what it looks like a vent on the 22mm CH pipework, facing upwards. Can somebody tell me if the stated could be the reason why the radiators are not working? I was thinking in installing a tee (sideways) to connect the Radiators to the system. HELP!!

