I am removing the bubbles from the radiators just before winter comes. Lower floor and mid floor is fine. Bubbles got removed and water started running and I closed them. However, at the top floor bubbles are removed but no sign of water in the radiators. Can it be
1. a pump problem as it does not pump up to the top floor?
2. a calcaire problem that there is blockage?
Is there anything I can try before calling the chauffage man?
Thanks a lot for the suggestions. Have a nice autumn!