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-   -   Water pipe thump noise (https://www.askmehelpdesk.com/showthread.php?t=464036)

  • Apr 11, 2010, 11:54 AM
    watchdog123
    Water pipe thump noise
    A real challenge, OK here we go... About six months ago a thumbing noise was very evident when the toilet water tank finished fillimg up or when the hot water faucet was closed. I was almost certain that it was because of loose water pipes, so I ripped apart walls where the pipes were not visible and replaced and added fasterers. The noise went away for a few days then re-appeared. Next measure was to drain the water pipes by shutting off the water supply into the house and opening all taps. After about fiveteen minutes I turned off the faucets and turned the water supply back on followed by turning the faucets back on to expel the air, the thumping noise was gone only to re-appear a couple of days later when the toilet filled or when I closed the hot water faucet. Assuming it was the up stairs bathroom faucet, I replaced it, problem still there. Something started to come together, the noise only re-appeared after the shower was used. I did a few test runs, sure enough the noise only re-appeared after a shower, I shut off the water supply and drain the air, the thumping noise is gone and once again only re-appears after a shower is used. At this point in time I am totally confused and would appreciate your help.
    Ivan Petrs
  • Apr 11, 2010, 02:01 PM
    KISS

    Typical solutions based on what you said:

    1. Rebuild/replace shower cartridge
    2. Loose washer or stem in shutoff
    ... Inspect, replace packing, washer or tighten packing nut)

    You may find that vibration only happens at or a near a certain flow.

    It could be as far back as a main shutoff. The shower is a high flow fixture.
  • Apr 11, 2010, 02:51 PM
    hkstroud

    When you tore the walls apart did you find any air chambers or water hammer arresters"? Air chambers are just a length of pipe about 18-24" long pointing straight up. Water hammer arresters are the commercial version?

    https://www.askmehelpdesk.com/member...r-aresters.jpg

    When a fast acting valve closes the abrupt stoppage of the water flow can cause the pipe to bang against the structural members. The air chambers and hammer arresters provide a cushion, like the shock absorbers on you car, to absorb the temporary increase in water pressure.
  • Apr 11, 2010, 03:06 PM
    ballengerb1

    You could also consider replacing the te fill valve on the toilet with a brand not know to be so fast acting when it closes. Try a Fluidmaster 400A
  • Apr 11, 2010, 03:29 PM
    manhattan42

    Like hkstroud said: Water hammer problem.

    You need to install hammer arresters.
  • Apr 11, 2010, 04:50 PM
    truck 41

    Do you have a pressure regulator on your home? If your hear it on both hot and cold sides then perhaps it's a pressure problem, check the pressure on the house with a water presser gauge. You can pick one up at a hardware store. Goodluck. ---zeke---
  • Apr 12, 2010, 05:52 AM
    speedball1
    1 Attachment(s)

    "Water hammer" happens when you abruptly shut off the water. You have at least 40 pounds of pressure pushing the water flow. The weight of the water hitting a 90 degree bend causes the sound that you hear. We put in air chambers to cushion the hammer much like the shocks on your car.
    Back in the 60's we were required to to put air chambers on all bath lavatories and kitchen sinks. Over time water and condensate built up in them and they must be recharged. First turn off the house at the main house shut off valve. Then open hot and cold faucets at the farthest bathroom to prevent air lock.(This is important.) You will find under each fixture little brass or chrome valves. These are called angle stops. With a small pail held under the angle stop to catch the run off look under the handle of the stop and you will see a nut with the stem running through it. This is called the bonnet packing nut. Put your wrench on it and back it off counterclockwise. Now open the stop and remove the stem and washer assembly, The stop will began to drain. When it has quit draining reassemble the stop and move on to the next one. Do this on each one of your angle stops. There will be six of them in a two bath home. When you are done, close off the faucets you have opened, turn on the water to the house, and give yourself a pat on the back.
    You have just recharged your air chambers and saved yourself a hefty service call bill.
    Zeke asked a good question,
    Quote:

    check the pressure on the house with a hose biub pressure gage,(see image) you can pick one up at a hardware store. Goodluck. ---zeke---
    Answer him. Hope this helps you out and thank you for rating my reply. TOM

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