Loud cracking and popping noise in the wall when draining hot water.?

Question

Everytime I use the hot water in the bathroom sink and it goes into the drain, there are really loud popping noises coming from the wall. It's not the water supply line because it does it when I just pour hot water from another source down the drain. It only does it in the winter time. It sounds like the wood studs in the wall are being snapped in half. It's that loud! I read somewhere that it's the pvc pipe expanding and contracting but I can't believe it can cause such a loud noise. It doesn't do it with cold water down the drain but sometimes it does make one pop noise, so I think water pressure has an effect. But hot water definitely makes the pop noise steadily. I've mention it to the landlord and they just blow it off saying they're not going to tear down a wall to investigate the noise! I'm afraid of a sewage leak! What's causing the noise and should I be concerned?

Answer 1

It's more common in apartment complexes, but it is completely normal. The sound is from expanding pipe joints moving a fraction of a millimeter. It makes a loud noise, but it completely harmless. I have the same thing and I asked my complex maintenance manager.

Now, if you hear gushing water.... that's a different story.

Answer 2

BrewMan sounds correct. Now why don't you test it to make sure its the drain and not the supply line? Heat a big pot of water on the stove. (No need to boil, we just want it at say 140 F, which should be the max for most hot water heaters.) Dump this down the drain - if you get the same effect, you know its nothing to do with the supply, merely expansion.

Answer 3

I think the brew man is tellen ya right. You will hear the noise because of the pipes expanding and contracting. Especially if they used an expanding foam to seal gaps in the walls. when the pipe expands it pushes on the foam or something else the pipe is rubbing on, creating your noise. Common, especially with cpvc water lines. We get alot of calls where people think they have leaks, only to cut the wall open and find this same scenario going on.

Answer 4

First of all it should not be pvc your drainlines in newer construction are ABS.It sounds to me whats happening is that someone forgot to glue a joint and the expanding of the pipe is possible to cause a tink or pop.If it is really LOUD then it's probly a ghost that doesn't like hot water.Sounds like someone has to crawl or what ever underneath your dwelling and investigate.

Answer 5

Your renting, landlord has been advised, send him a letter, so when it comes to the time to tear walls down, they have been advised. Until then you may want to try a powder drain cleaner, NOT those overpriced liquid drain cleaners, they're really for plug ups

Answer 6

expansion in the drain pipes.Mine does the same thing and is normal