Everyone once in a while, some of the pipes in our house make some noise, mainly only when you flush a the one toilet, or use the washer. When using the sinks, hoses, or shower, the noise is not heard.

Its a rhythmic, light 'thumping' noise. It could almost be considered a clicking noise.

It only lasts while the water is on, and only on the washer and flushing a toilet. Im assuming (since it happens while the water is on and not after its off) that this wouldn't be 'Water Hamer'.

What could be causing this noise, and what should one do to correct it?

Update: if it helps, the noise is at a rhythm of almost one per second, maybe a little quicker, but not really less than half a second.

Update 2: To be more accurate, the noise is actually probably a little faster than once every half a second. Here is a link to a M4A file (recorded from iPhone). This was recorded on the wall opposite of the bathroom, where the pipes should be.

  • Could the sound be gurgling from drains (which would indicate a venting problem)? I would question if it's a pressure regulator problem, but that should cause banging when any valve is opened.
    – BMitch
    Aug 16, 2011 at 15:18
  • The sound sounds like its coming moreso from in the wall versus out of the drain. And the drain from the washing machine is rather new.
    – jmlumpkin
    Aug 16, 2011 at 17:42
  • Does it make a difference if you run the cold water or the hot water? I ask to help split up the pipes. If it only makes the sound on one then you know whatever is making the sound is probability after the split to the water heater. If both make the noise, then look for something before the heater.
    – NitroxDM
    Aug 16, 2011 at 21:48
  • Well, one of the devices causing the sound is the toilet, so I would expect its not hot water. But good point.
    – jmlumpkin
    Aug 17, 2011 at 1:48

6 Answers 6


Can you locate the noise (tricky because I am sure it is also traveling along the length of the pipe)? Is it coming from a particular wall? It could be a loose pipe that is moving a little (only when water is running through it) and hitting something.

  • It sounds like the wall between where our kitchen and bathroom is. I know the drain pipe for the sink in the bathroom is in this wall (and so is the incoming water for the toilet). Im not sure if the water line for the washer branches off here, its at the other side of the house (a rancher), but very possible. But would you get a rhythm like this?
    – jmlumpkin
    Aug 16, 2011 at 17:45

If the pipes were cold (cold day) and the water being drained was fairly warm, the sound could be due to the pipes expanding from the heat.

Check out this link, about pipes making a knocking sound due to heat expanding the pipes.


It's not accompanied by any change in water pressure, is it? If it's rhythmic, it could be the pressure switch toggling (which would indicate a problem with your pressure tank).

  • I have not noticed a change in pressure, but it also seems these two devices would be hard to notice pressure changes on. But if I do use another sink or something in the meantime, we have not noticed changes in pressure on those devices.
    – jmlumpkin
    Aug 16, 2011 at 20:07

Is it possible that the supply line is banging against the wall as the water is flowing through it? It might also be water hammer, but that isn't normally rhythmic.

Is your water from a well or a from the city? If it's from a well, it might be something with your pressure tank or from the well pump cycling for some reason.

Maybe you could post a short video here?

  • Yes, I was thinking of doing that. And its city water.
    – jmlumpkin
    Aug 18, 2011 at 13:51
  • 1
    Ok, just added a link to the original question with an audio file.
    – jmlumpkin
    Aug 18, 2011 at 13:59
  • sorry, i have no idea what that sound is, you may have to do some exploratory surgery to the wall. it might just be loose pipes moving as the water flows through them.
    – Zach
    Aug 19, 2011 at 0:22

Found this on the internet. Ours started thumping after they changed the inside water meter.

A continuous thump, thump, thump noise, consisting of evenly spaced thumps when the water is running may be caused by a under-size water meter. The noise may also be a tapping sound. The noise may appear to come from the water heater as the tank amplifies the sound. Check the water meter, you will likely hear the noise coming from it. The solution is to install a larger meter.


I get a consistent, regular, periodic drumming noise while water is running. (The sound file you posted is broken now so I can't compare it). I have iron pipes from my meter to my house where it transitions to (mostly) copper distribution.

One hypothesis I have is the noise is coming from the water meter. There's chatter here and there (non-peer reviewed, unsubstantiated) that high rates through the water meter can cause a sound and the pipes transmit the sound.

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