Please help me understand my Radiator?

[stutter55]

I recently moved into a new place and I am trying to understand how my radiator works.

I have took a picture and posted it here. I know that in the basement there is a huge water boiler.

http://i278.photobucket.com/albums/kk101...

My place is currently colder than I would like at around 66 degrees (crazy thing is that I am on the top floor (3rd), I would think I get all the heat.) (Also, I have no regulation of the thermostat, there is only one thermostat in the building and its in the apt on the 2nd floor).

I was unscrewing part A all the way and when it fell off, a huge load of pressure started shooting all over the room.

My guess is Part B needs to be unscrewed all the for the pressure to come through. Than part A regulates the heat?

If I unscrewed part A all the way will it help or just depressurize the whole place and ruin everything?

FYI - All the radiators are hissing alot. Not sure what that means. But I was reading online about something called bleeding? Is that what I should do here?

What is the point of A? Should be shut tight?

I have talked to my landlord and his claim is that there is not enough pressure to get to the 3rd floor (maybe be BS). The thermostat is currently set at 71 degrees and the apts on the 1st floor are at 74 degrees consistently, 2nd floor apts are at around 71, I am in 67-68.

Thanks in advance, I know its alot of info but this whole situation sucks.

[HayZee518]

Part A is an air bleed off valve. When steam hits it it should shut off. Part B is your shut off for the steam. Any steam that condenses in the line or radiator runs back to the boiler along the same pipe. sometimes you may hear a clanging in the line - this is the steam hitting the water condensate and flash boiling it.