hi lads, went to a job today to fix a towel rail , wasnt getting warm , anyway sorted that and noticed it was only getting hot to middle (top full of air) now i cant open the bleed key as its totally rounded/flatend , and i cant replace it as ive never seen one like this before in my 5 years plumbing . i cant either replace the towel rail as the feet ar aroud 2 inches round and some body has cut the non slip flooring around the, so if i was to fit a new one there would be 2 holes in the non slip around 2 inch round, there is no other fitting whatsoever in the top of the towel rail , any ideas how i can get rid of the air?????? system was an open vented!