by plumbbob »
Sat Nov 13, 2010 1:04 pm
It is possible the valve has seized.
There is a lever on the side that operates the valve manually. If you push it across, the valve should open allowing hot water to the radiators. It is possible to lock the lever open permanently so you can at least get warm. (The hot water may need to be on to make this work.)
Maybe operating the valve will free it off so it will work normally from then onwards.