Thanks, I may have to do that but if it isn't smoking, what causes it? Surely its a design fault. I should be able to sit around smoking giant cigars if I wanted to. I'm not talking about slight staining here. It is very dark brown and is very noticable.
I have moved into a new build property and since using the radiators of my electric central heating, the walls are becoming stained brown just above the radiators. Anyone got any ideas please?