What Device or Equipment Could Be Making This Type of Water Pipe Banging Noises?

Magic Mirror on 21/09/2025 - 14:36
Last edited 21/09/2025 - 15:05

I live in a unit block and in recent weeks the water pipe banging noises from the unit below seems to getting louder and more frequent. What makes it strange is that sometimes these sounds happen in a sequence and in a particular pattern.

Quite often multiple of these banging sounds would happen in succession over several minutes. Initially the gaps between them could be 10 seconds apart. Then it changes to 15 seconds apart. Then changes again to 20 seconds apart before stopping. They are often in this pattern (or similar) but not always. Edit: these sequences happen many times through the day (morning to night), perhaps a dozen times or more.

Another strange thing is the banging sound vs water flow. I can manually create a banging sound by turning off the tap quickly. This means the banging sound happens after the water flow. But with these banging sounds from the neighbour, they go like this:

  • loud bang
  • whooshing sound (water flow through the pipe)
  • clicking sound (or softer bang)
  • water flow stops
  • next bang

So they probably have connected some kind of device or equipment to the water pipe to be making these sequence of noises. Does anyone know what that might be? Thanks.

Home & Garden

Comments

  • CrispyChrispy on 21/09/2025 - 14:38
    +1

    yeah nah dont worry that's just old mate cleaning yer pipes

  • scrimshaw on 21/09/2025 - 14:41
    +16

    Sounds like a water hammer that you're hearing. Usually rectified by an installation of a water hammer arrestor

    https://www.workshop.bunnings.com.au/t5/Bathroom-and-Laundry…

    Basically since water isn't compressible, if you shut off a valve quickly, water that was previously flowing slams into the blocked valve (like a hammer). Hammer arrestors work like an anti-surge device by having an air bladder that can compress if the pressure builds up.

  • Daabido on 21/09/2025 - 14:48
    +6

    It could be a new washing machine. When researching a new one I came across posts about ones that cause water hammer.

  • randombrick on 21/09/2025 - 14:50
    +3

    Washing machine, most likely.

    Spent hundreds of dollars on plumbers to fix the water hammer in my house.. They installed multiple arrestors, etc. But no luck.. Now, I just live with it.

    • JIMB0 on 21/09/2025 - 20:11

      Have you tried closing the tap most of the way? Solved it for me.

    • andrew1879 on 22/09/2025 - 09:33
      +1

      Replacing the taps with 1/4 turn ceramic type fixed washing machine water hammer for me.

  • DashCam AKA Rolts on 21/09/2025 - 14:53
    +1

    Washing machine or dishwasher going through wash/rinse cycles with water hammer due to opening / closing of inlet valves. As @scrimshaw said an arrestor should quieten things down.

    If the noise has only become noticeable recently, probably due to water pipe fixing being inadequate and has failed.

  • AndyC1 on 21/09/2025 - 15:05

    New washing machine.

  • Magic Mirror on 21/09/2025 - 15:06

    Thanks for the comments so far. I forgot to mention (now added) that these sequences of noises happen many times from morning till night, perhaps a dozen times or more. So I doubt it could be a washing machine or dishwater.

    • endotherm on 21/09/2025 - 17:12
      +2

      It could be anything that has a water cutoff valve that operates suddenly, like the aforementioned washing machine. It could be water dispenser/ice maker in the fridge or evaporative cooling on the roof or any number of other appliances that run water, then cut it off suddenly. Knowing what is causing it isn't going to help you at all. You need to do something about it like fitting a water hammer arrestor or two near the pipe that is banging inside the wall. If you are that curious, approach your neighbour and politely ask if they know what they are running that causes the problem. You are not going to be able to make them do anything about it, but it might satisfy your curiosity.

  • djones145 on 21/09/2025 - 15:58

    i had issue after i installed a new shower head. had banding noises. the plumber came and said its becuase new shower heads have a flow inhibitor to slow the flow, he pulled it out and it stopped

  • Euphemistic on 21/09/2025 - 17:28

    Our house has developed warer hammer. Each time the cold water is turned off there is a bang. That means once when toilet stops filling, once when hand basin turned off etc. It will bang many times when the washing machine is filling because it fillls some, checks the level, then adds more. Dishwasher is similar.

    If you turn off the tap really slowly it wont bang, but that doesn't happen often.

  • tenpercent on 21/09/2025 - 22:36
    +1

    Quite often multiple of these banging sounds would happen in succession over several minutes.

    Your downstairs neighbour got a new friend?

    these sequences happen many times through the day (morning to night), perhaps a dozen times or more.

    What a stud! That's real stamina.

  • payton on 21/09/2025 - 23:31
    +1

    Reason #157 of why people don't live in apartments

    • tenpercent on 22/09/2025 - 08:57

      Captain Planet says:

      But it's gooderer for the planet

      • payton on 22/09/2025 - 13:16

        The planet survived an asteroid hit & explosion greater than all nuclear weapons combined
        Here's to it surviving another 4.5 billion years 🥂

  • Banks on 22/09/2025 - 08:11

    Normal sounds as far as I am aware.

    It could be someone flushing the toilet multiple times because that is very common with people needing to flush twice due to legislation that limits the amount of water a standard toilet uses…

    Remember, the government dictates how much water you use with every flush.

    It could also be a new neighbour/renter that likes to turn their tap off regularly whilst washing dishes to save water…

    It is hard to say what exactly it is unless you go in for a chat, and then see what they are doing at the time the noises are being made. Maybe a sound recording would assist us.

    Front loader washing machines are the worst, they stop and fill multiple times during the cycle.

  • Chewy2221 on 22/09/2025 - 08:30
    +1

    Copper pipes are held together with "soft" solder & can rupture if constantly subjected to water hammer. I suspect that it is just a matter of time before this will happen. Perhaps talk to the neighbour & suggest they raise it with the re agent or owner. I'm sure the owner would be happy to avoid potential water damage to the property. Good luck

  • LFO on 22/09/2025 - 16:28

    From my experience: a "smart" washing machine topping up water level, mixing hot and cold to get the right temp, rinsing and spinning, etc.

    Sometimes a dishwasher will do it too.

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