hi, i need to move a radiator in my mothers house and i've got a few problems ,first of all the radiator in question is on 10mm pipe and most of the others are on 15mm pipe this radiator used to get hot but for some reason now only gets luke warm, we did have this radiator replaced last year and was told that it was probably blocked but it's just the same, if you turn all the rads upstairs off you can get it hot do you think it will just need to be balanced ,the other problem is one of the other radiators downstairs has a snapped off bleed valve so if i drain the system i would need to replaced it so i was thinking of using one of those freeze kit and was wondering if they work ok. 
