Good evening, Since moving to my 3 bed house 2 years ago the living room 1 radiator has always been naff. Iv tried all sorts, tried balancing the system, even closing all valves and leaving this rad both valves open with no luck. My thoughts that it could be blocked so I changed it but also went bigger 400 > 600 height one . Its been working a treat however its come back again with top half warm and cold at the bottom. The right valve is hottish and the left valve is cold. Any other valves in the house are piping hot unable to touch. The pipe work is 8mm microbore :/ . The living room gets too hot which is next door. 2 rads downstairs, 3 upstairs, 1 towel rail Can anyone suggest my next plan of action with this problem ?