I have a 1941 ranch house with two floors (SFH turned into a non-conforming duplex) and the pipes are making a loud banging sound every day and night. (Day is less followed, less heard because I'm not around and not focused on it, and usually working with the radio.) When I do make note is at night. It happens 3-4 times a night. At all ends of the house (so sometimes it's loud, sometimes softer depending on how far from my bedroom).

I tried turning off the irrigation and that did nothing. I changed the flapper on both toilets. Nothing. I turned off the water main, and that made it all go away. Of course I can't do this every night (Although I wish I could). I don't have ice makers or dishwashers in either unit. Essentially nothing is happening from the human side (showers, toilet, etc.) but I still have this nightly noise.

My neighbors don't have irrigation (I asked). I do live near a water district pump station but they tell me it's not that. One time the noises stopped when the downstairs tenant was away for a week (but not completely).

I'm desperate for ideas or ways to solve this nightly disruption. Help!

3 Answers 3


It sounds like you have baseboard water heating (aka hydronic heating). The copper pipes circulate boiling water around your house and heat your home.

The heating and cool-down cycle causes the metal to expand and contract which would be the culprit of the noise.

  • I have a furnace and forced air heating unfortunately, but it's a good point for another old house! Thank you.
    – Larissa
    Oct 5, 2022 at 15:48
  • @Larissa Is it a single bang or does the noise last for several seconds? What kind of plumbing do you have: copper, galvanized steel, or PEX?
    – MonkeyZeus
    Oct 5, 2022 at 15:51
  • It's typically 3-4 bangs (sounds just like someone grabbing a pipe and shaking it). I have mostly galvanized pipes with some copper.
    – Larissa
    Oct 5, 2022 at 16:39
  • @Larissa So do the pipes ever do this when you simply use water?
    – MonkeyZeus
    Oct 5, 2022 at 17:00
  • 1
    @Larissa Does it coincide with your water heater heating up water?
    – MonkeyZeus
    Oct 5, 2022 at 17:47

Water Hammer Arrestors.

Image from plumbingsupply.com, no endorsement implied

Or, if old-style with dead-end pipe sections doing the arresting, (likely for 1941 if they were installed at all) just shut off the water main, open all faucets and drain the water from the pipes, then close up and refill to replenish the air bubbles in the dead ends that slowly dissolve away.

  • I haven't truly done the air bubble clearing, my plumber poo poo'd the idea, but I will try this weekend. Thank you.
    – Larissa
    Oct 5, 2022 at 15:49
  • do I also need to clear water from outside hose spigots too?
    – Larissa
    Oct 5, 2022 at 19:30
  • Might as well. Main thing is having higher faucets open to let air in, and the lowest drain in the building open to let water out. But if you let most of the water out the outside faucets, that's less to put in a bucket inside if there's a lower drain inside.
    – Ecnerwal
    Oct 6, 2022 at 13:56
  • So I did all of that yesterday, drained the house of water starting high and ending low. Then turned the water main back on and opened up everything starting low to high (and including outside spigots). I did two rounds to try and clear air. Went to bed last night and it was silent the entire night until 5:06am when banging happened, and then happened 3 more times in that single hour. It all came from basically the same spot, which is an area that also has the water heater and under my bedroom. You can get my frustration here. (I did not open up the pressure valve on the water heater.)
    – Larissa
    Oct 6, 2022 at 15:59
  • Pressure valve should not need to be opened, and often leaks if you do... So, you may not have dead-end hammer arrestors, in which case you may need to add hammer arrestors to the system. It's worth trying the drain step because you normally can't see them if you do have them, and sometimes they are there. If they are not there, you'll need to add them, which is obviously more work.
    – Ecnerwal
    Oct 6, 2022 at 16:14

If the noise stops when the other resident in the building is away (or at least significantly reduces), it's highly likely that it's this other person's water use that's causing the problem for you.

The fact that it didn't completely stop could be due to a leaking toilet, for example, so it continued even though the other tenant wasn't there.

If the problem is in the other apartment, then you can either knock on the door and politely ask for assistance in identifying the cause so you can both take it up with the landlord, or (especially of the other guy isn't particularly friendly) just go straight to the landlord and ask him to investigate.

  • Thanks @FreeMan. I'm the owner. I changed the flapper on their toilet and noises continued.
    – Larissa
    Oct 5, 2022 at 19:29

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.