My heat is fueled by oil. The valve, which looks like a bullet, that is attached to the unit was letting too much steam escape in one of the rooms...the wall above it was wet as was the floor. I bought a new "Steam radiator vent air valve" #A884 and when I tried to take off the old valve and I needed to use a hammer to get it to turn...well it finally turned and turned but wouldn't come off...only the "bullet" turned, the screw in part didn't budge. So I decided to leave it but couldn't tighten it back again and just now when the heat went on the sound was unbelievable and everything including the windows were steamed. Help....

 

Steam vent valves have a mechanism that causes the vent to close when hot so that steam isn't released into the room. Your valve's mechanism wasn't working well and was releasing steam so the vent valve needed to be replaced. Taking a hammer to the vent valve was probably too strong a tactic for removing it. Steam radiator vent valves are not very robust. A quality vent valve should have a hex that you can get a wrench on. Your vent valve probably didn't have a hex. Some vent valves can be removed by hand, but if the valve had been in place for many years, this might be too difficult. This valve could have broken even if you were trying to unscrew it by hand. Regardless, the valve is broken and providing no resistance to the flow of air or steam. With a broken vent valve, the radiator is now venting too fast, getting too hot, and preventing other radiators in the house from getting warm. This radiator should be shut off using the steam isolation valve until fixed. You'll probably need a plumber or a handy neighbor with proper tools to get the old valve off and to remove its threaded spigot from the radiator. Rather than just cutting the valve off with a hack saw, it might be better to just pry the bullet shaped body off from the threaded spigot, in hopes that with valve body out of the way, you can get some vice grips on the spigot to unscrew it. Failing that, someone will need an extraction tool to remove what's left of the valve spigot from the radiator. If the extraction tool doesn't work, you'll need to drill the old spigot out and retap the hole and possibly install an adapter to mate with the new vent valve.