# Odd plumbing noises

**URL:** <https://boards.straightdope.com/t/odd-plumbing-noises/390146>\
**Category:** Factual Questions\
**Created:** [January 30, 2007, 6:41pm UTC](https://boards.straightdope.com/t/odd-plumbing-noises/390146 "2007-01-30T18:41:50Z")\
**Posts on this page:** 3\
**Page:** 1

<div class="post-metadata">

**Author:** ![Don\_t\_Call\_Me\_Shirley](https://avatars.discourse-cdn.com/v4/letter/d/f4b2a3/32.png) [@Don\_t\_Call\_Me\_Shirley](https://boards.straightdope.com/u/Don_t_Call_Me_Shirley)\
**Post date:** [January 30, 2007, 6:41pm UTC](https://boards.straightdope.com/t/odd-plumbing-noises/390146/1 "2007-01-30T18:41:50Z")

</div>

In the last couple of days I have noticed strange groaning noises coming from behind the walls every time I turn off a water faucet or when the toilet stops filling. What is the cause of this, and it is something that I need to get fixed?

I thought it might have something to do with the fact that we’re having a cold snap, and the water coming in to the house is colder than normal.

---

<div class="post-metadata">

**Author:** ![robby](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/robby/32/11048_2.png) [@robby](https://boards.straightdope.com/u/robby)\
**Post date:** [January 30, 2007, 8:16pm UTC](https://boards.straightdope.com/t/odd-plumbing-noises/390146/2 "2007-01-30T20:16:06Z")

</div>

It sounds like [water hammer](http://www.factsfacts.com/MyHomeRepair/PipeNoises.htm).

It’s definitely something to get fixed. It can weaken pipe joints to the point that you get a leak in your walls. Get a plumber to look at it.

---

<div class="post-metadata">

**Author:** ![A.R.Cane](https://avatars.discourse-cdn.com/v4/letter/a/ee7513/32.png) [@A.R.Cane](https://boards.straightdope.com/u/A.R.Cane)\
**Post date:** [January 30, 2007, 8:30pm UTC](https://boards.straightdope.com/t/odd-plumbing-noises/390146/3 "2007-01-30T20:30:25Z")

</div>

[QUOTE=Don’t Call Me Shirley]  
In the last couple of days I have noticed strange groaning noises coming from behind the walls every time I turn off a water faucet or when the toilet stops filling. What is the cause of this, and it is something that I need to get fixed?

I thought it might have something to do with the fact that we’re having a cold snap, and the water coming in to the house is colder than normal.  
[/QUOTE]

Since it just started I’d suspect your toilet’s fill valve is worn and causing a vibration just as it tries to close. You can verify this, the next time you hear the groaning, by removing the tank lid and manually lifting the float device. If this stops the noise, you’ve found the problem. It may be possible to repair the valve, but it’s usually easier to replace the whole device.