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only 1 radiator bangs

Paulvar1 Member Posts: 8
I have a 1 pipe steam system with 1 radiator that gives me a hard time. I increased the pitch to this small radiator and bought a new vent. It is on the first floor so I can see the pipe that supplies this radiator has quite a pitch toward the main steam supply. This is the first radiator that comes off the main supply. All the pitches seem perfect. This 1 radiator bangs loudly when the system just starts. That indicates water returning to meet the steam. What can I do to stop the banging. Standing in the basement I can definitely tell this 1 pipe is the culprit. You can almost feel the vibration. It began when I replaced the boiler at Christmas time. Pressure cuts out just under 2 lbs and wont go any lower.


  • Jamie Hall
    Jamie Hall Member Posts: 23,324
    If we assume that all the "horizontal" pipes have adequate size and pitch -- at least 1 inch end to end, and not less than 1 inch in 10 feet -- and that the takeoff ;;from the main is at least 45 degees above the horizontal, and that the radiator itself is pitched to drain...

    Then the next step is to slow the vent drastically and see i that helps.
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • dopey27177
    dopey27177 Member Posts: 887
    Try lowering the steam pressure to 1 PSI off and an 8 ounce back on.
    Your problem may be that the size of the pipe off the steam main may be to small.
    If your pipe supplying the radiator is 1 inch and there is more than 6 feet developed length of pipe the supply pipe should be increased to 1 1/4 inch up to the horizontal connection to the radiator.