does rad have a thermostatic rad valve on it. if it does most trv heads will just scew off the vavle.there are some that dont and need screwdrivers or allen keys to get them off. once you have removed the head you will see a pin sticking out of the valve. for the valve to work this pin must be able to spring in and out. if it doesnt the valve seating is stuck. to free it off you need to hit pin, not violently, to free seating. a small hammer will do this. if pin has freed it will spring in and out when pushed
gary, November 2010
