I have one double radiator in the house that does not have a bleed valve like all the others. Instead of the square pin, there is just a small round circle of brass thats practically flush with the end of the radiator. I cant see anyway of bleeding this radiator. can anyone help?
Sounds like that is a flush mounted plug, you have to get the plug out and screw in a bleed valve. You will have to drain part of system to get water level down.