Thank you Tony and Chrishutt.
Tony, I will try what you suggest and see if that works. Chrishutt, I don't exactly know where the leak is from. The first I knew of it was the stain appearing on the ceiling of the room below. When I checked the offending radiator, the carpet in the vicinity...
One of my radiators leaks when I turn the radiator thermostat off. No leaks once the radiator is heating the room, only when I twist the thermostat to off. Any ideas what is causing this?
It's frustrating because that particular room gets quite hot whilst other rooms need the heat. So the...