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Cool Steam Pipe Noise

Tom Hopkins
Tom Hopkins Member Posts: 552
Does anyone know how to reduce noise from cooling steam pipes? I have a one pipe steam system in my house, and I sometimes get a loud metallic snapping sound from some pipes (or maybe the radiators) as they cool. It almost sounds like water hammer, but the sound happens just once for a split second, an hour or more after the boiler has been off.

I believe it is coming from one or more branch lines off the main--which are insulated. Can this noise be prevented? At most, there is one pipe support fore each 10 to 14 foot steel branch pipes. Should there be more? Thanks for any thoughts on this.



  • Brad White_184
    Brad White_184 Member Posts: 135
    Isolate the noise

    Find where the noise is occurring. This may require that you sit in the basement and wait, so bring a book. :)

    I suspect that a pipe or fitting is binding against wood structure then releasing when cold.

    Before you kill an evening in the basement (unless you enjoy watching your boiler which is never time wasted at my place :) check out obvious spots where there may be binding. Then focus on those when cool-down time comes.

    The solution may be a chisel to remove a sliver of wood or a re-hanging of the pipe or an insert of some time to smooth the passage. Too many iterations of a situation to say just what to do, but you will know when you see it.

    If it is pipe to wood contact though, I would want to see at least an inch airspace (net pipe to wood) or better yet, insulation with some space to spare.

    My $0.02

  • Tom Hopkins
    Tom Hopkins Member Posts: 552

    Thanks. I'll give it a try. Some of my risers do seem to be tight against the wooden subfloor.

  • Steam pipe noise

    Just had a Weil-McLain SGO series 3 oil-fired steam boiler installed to replace an old conversion to an old coal furnace.
    Trouble is when the new boiler cranks up and steam starts to move, several pipes make loud hammering noises. Our plumber thinks it is the malfunctioning turn off valves not allowing the cool water to return properly. He wants to replace the valves with new ones and replace a run of black iron pipe with copper. What do you think?
  • The new boiler

    is probably not piped properly. Post some pics here and we'll have a look at it.

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