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severe banging and water spilling out of radiator

Will1989 Member Posts: 1
I have a building with 114 units and 2 well McLain boilers running the system. Since this fall season has started, at the very end of my steam line there has been intense banging noises going up each riser. Also, i have a one pipe radiator tied into the steam main and it has been gushing water nonstop until the steam finishes its cycle.
The radiator is properly pitched as well as had new piping go down to the steam line.
I have checked all the steam traps and they are all clear.
I have bled out the condensate from that side but yet every time a new cycle turns on, the banging happens again as if there is a lot of water in the steam main. I also raised the boilers psi to 2 from 1psi to see if the steam wasnt reaching that end and thus turning to water before reaching the end of the line.
I took a peek at different areas of the condensate line and it does not show that it is plugged. so, i am at a loss of what to do. Does anyone have any ideas?

Thanks in advance


  • Jamie Hall
    Jamie Hall Member Posts: 23,454
    I rather expect that raising the pressure didn't help a bit, did it?

    The question is where is the water supposed to go? It's going to be there -- whatever pressure you use -- and at some point it must have had a way to get back to the boiler.

    Has the slope of the main been changed? Is there a sag somewhere in the length of the main (wouldn't take much)? A hanger failed? Or is there a drip to a wet return at the far end of that main which isn't flowing for some reason?


    Could be a lot of things, but you have to look at it and consider: if there were water in that pipe, how would it flow back the boiler? If any water can accumulate, even a small amount, the steam will push it to the nearest bend, as you have discovered.
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • neilc
    neilc Member Posts: 2,709
    is the gage showing the increased pressure you set to ?
    and is the pressure control device seeing the proper boiler pressure?
    aka, is the pigtail(s) clear?
    known to beat dead horses
    EBEBRATT-Ed Member Posts: 15,635
    you need to lower the pressure as much as possible. raising it make every problem worse