I wonder if any one could help me as i am loosing my marbles with this central heating system. We have a rad in a loft donversion that is cold. If we turn the heating on and set temp over 70 it becomes slightly warm any other time you can feel it trying to get hot but it never works. It has a thermostatic thing on one side, i have checked pin and it is working fine. Rads run off a combi boiler so shouldnt have air in them. One side of rad has this thermostatic thing other just has a copper flat ended thing with a white cover over that does nothing (im sorry for crappy descriptions but i dont know technical names), anyway the pipe at this side of the radiator is cold where as the pipe at side where thermostatic doo dah is ret hot, any ideas what it may be???? Please help