Read some advice on this site today and I turned all the radiators off and kept the ones on that were not heating up good. I turned on the remaining radiators one after the other but after a while our bedroom radiator (which is the main culprit) started to cool down again. Is it time to call in a plumber? ![Evil Twisted :evil: :evil:](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)