To dream of a radiator suggests that you may not be getting the warmth that you desire from a loved one. You would like to remedy the problem.
To dream of a cold radiator indicates that you might like to examine your expectations of another, as they may not match a fear of intimacy that lurks within.
On the other hand, an extremely hot radiator may mean that your expectations are too high and there is a need to look within. You could be withholding the love.