I have 2 tower radiators in the living room, 1 is boiling, the other rarely gets luke warm. I have drained it and refilled it, bled the whole system, yet it still fails to heat. The inlet pipe us really hot, yet the return pipe is cool. I have turned all rads off in house, including both valves, to try and force the water through and that does help a little as the rad gets hot, but as soon as I open up the rest of the rads the tower 1 goes back to being useless. Any advice greatly appreciated as the missus wants the xmas tree in the living room so will have to turn the hot 1 off!! Thank you