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Hammering unit heater

I have a ceiling mounted steam unit heater that makes a clack-clack-clack noise on the off-cycle. I believe that it is because the condensate has to be pushed up from the heater to the return piping. The noise stops when steam starts flowing through the coil. I wonder if replacing the check valve on the outlet would help. Note: steam trap is fine. Heats the entryway location fine. Has been noisy since i started here 8 years ago.


    EBEBRATT-Ed Member Posts: 15,539
    There is not much you can do. You need enough steam pressure to raise the condensate. 1 lb of steam pressure for every 28" of lift.

    They did not pipe it the best way though. You should come off the coil with a 90 and drop down right at the coil for 12" if possible. If you can't get 12" get what you can. Then go horizontal with the strainer steam trap and check valve. Keep the horizontal to a minimum then rise up and pipe into the top of the condensate return if possible. That keeps condensate in the return from not running down the return line.

    It may help and it may not your going to have some noise when lifting condensate.

    If you want no noise install a small condensate pump
    D. McLean
  • DanHolohan
    DanHolohan Member, Moderator, Administrator Posts: 16,527
    You need a vacuum breaker immediately after the control valve. 
    Retired and loving it.