I bought a small used cast iron radiator about 6 months (about 12 inches wide by 24 inches high). I finally connected it up to the hot water heating system in an apartment that I will be renting out.
But, when I went to bleed the radiator, I noticed that the bleeder valve is in the end of the radiator only about half way up from the floor (about 12 inches up). That means I cannot bleed the air out of the top half of the radiator. After thinking about it, I figured out that it probably used to be a steam radiator that had a steam valve at that height. I guess they replaced the steam valve with a bleeder port and called it a hot water radiator.
At the top of the radiator on one end in the corner there is a flat head screw going into the radiator. I am guessing that I could try taking out the flat head screw and replacing it with a bleeder valve there. Does that sound about right?
I am hesitant to mess with the screw. I don't know how hard it will be to get out although my first try broke a screwdriver tip before anything happened with the screw. I am thinking about heating the screw with a torch first before trying to get it out.
Any advice or suggestions would be appreciated.
I also thought that "there oughta be something" -- like a piece of small tubing etc. -- that I could attach to the existing bleeder valve from the inside that could be fed from there up to the top of the inside of the radiator. I assume that no such thing exists, but that seems like it would be a way to bleed the air from the top of the radiator rather than from the middle.
P.S. I also just posted this question at http://www.heatinghelp.com/forum-category/76/THE-MAIN-WALL .