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Help getting radiator to stop banging

Hi all,

Please excuse my ignorance...I'm a college student living in an old apartment for the first time with what I believe is a hot water/steam radiator (see picture below).

I believe the super turned the boiler on a few days ago, and since then the thing has been banging (steam/water hammer?) every time it starts up and I'm desperately trying to find a way to just turn the whole radiator off as I have my own personal heater that I use instead.

When I have the inlet valve (bottom left) completely open, it will do nothing, sometimes for hours, until night time when I assume it's cold enough for the boiler to start up. Then it will sometime hiss, gurgle, and always bang at least slightly. It does this 3 or 4 times at night every few hours and has woken me up for the last few nights.

I thought turning the inlet valve completely closed would stop it, but it does not. It does the exact same thing every night whether the valve is completely open or completely closed. Is it supposed to work like this?

On top of it all, it makes the noise but doesn't get warm or hot. Whenever it starts with the noise, I can put my hand on it and it's cool.

I've asked the super for help but the maintenance man wasn't able to come today and I'm sick of it waking me up for the last 3 or 4 nights.

I read somewhere else on the forum that turning the outlet valve (top right) counter clockwise so it faces down would stop it, but I've tried to turn it and it seems stuck. Is this the best thing to do? Is it supposed to be easy to turn? If I can't turn the valve, can I block the air hole at the top to receive the same effect as turning it upside down would?

Is there anything else I as someone who has no experience with radiators can easily do to get it to shut down and stop banging every night as I wait for the maintenance manager?

Thanks in advance; I appreciate any and all help.


  • nicholas bonham-carter
    nicholas bonham-carter Member Posts: 8,578
    Noisy radiator

    You should be able to turn the air-vent so it points down, which will stop the air escaping that radiator, but the noise may come from a point in the main supply which will be unaffected by your radiator Have you tried turning in both directions?

    A well maintained system should be silent, and even. When the maintenance man comes to check the system, have him cause the system to run so the noise can be heard by him.

    Curing this problem may be beyond his ability, and a steam professional may be required. What is your location?--NBC
  • JohnNY
    JohnNY Member Posts: 3,232
    Are you in New York?

    Maybe I could help you out and show the landlord the error of his ways.
    Contact John "JohnNY" Cataneo, NYC Master Plumber, Lic 1784
    Consulting & Troubleshooting
    Heating in NYC or NJ.
  • MDNLansing
    MDNLansing Member Posts: 297

    If that vent doesn't want to turn, be careful trying. You don't want to break it off inside the radiator. Does this vent ever get hot, or does it stay cold like the radiator?

    Try shimming the right side of the radiator a little. Rock the unit forward just a little and shove some cardboard or a thin piece of wood under the right rear foot. Then rock it towards the wall and do the same thing to the front right foot. Only shim the right side feet, not the left side feet.
  • mhandler
    mhandler Member Posts: 2
    edited October 2013
    Maintenance plans to cap the pipe

    Thanks so much for the help everyone!

    JohnNY, unfortunately I'm in the San Francisco Bay Area so that won't work out.

    The maintenance manager came today and took a look at both valves. He said he was planning to just replace the outlet valve, but the part hadn't come in yet as expected. In the meantime, he removed it, put some tape around it and screwed it back in. It's now loose enough that I can turn it to point it down.

    Ultimately though, he offered to come back tomorrow and cap the pipe that leads into the radiator. This seemed like the best option to me since, like I said, I have a small personal heater that I've been using the last few days anyway.

    If the pipe is capped, will there still be loud banging whenever the boiler starts?

    Again, thanks for the help.
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