Does anyone have the "wet" plinth heaters that run off the central heating with a little electric fan to circulate the air? What do you think of it, is it adequate heating? Is the fan noisy? Is there a fire risk given the dust that's generally under there? Do you need to hoover the dust out to avoid this? Does the stuff in the unit above get too warm? Opinions gratefully received. We're getting a kitchen extension soon & don't want to waste wall space where a kitchen unit could go.