I also have 1 cold radiator.
I did that I turned off 5 "working fine" rads, but still nothing, not even the slightest bit of heat. Mine is a rad in the attic but the rad in the attic bathroom works fine. i have bleed the rad. Could i have a blockage maybe? as there is no heat even in the pipes that feed the rad!.
Steve Tew
October 2008