Glub, glub, glub after turning off water

[Sondra N]

For awhile now, every time we run water then turn it off, there is a glub, glub, glub sound in the walls or maybe under the house. Apparently, air is in the lines somehow, but I don't understand where or how that is happening. Plumbers act like they've never heard of such a thing. Can't get them to understand that it has nothing to do with the drains/mainline. I can run water at the bathroom sink with the stopper closed, and hear the noise after shutting the water off. No water is draining. Happens after toilet fills, after washing machine fills, after water at the sinks or tub run.

Where should we look first? We do have a tankless water heater that is way past due on preventative maintenance (descaling and such)...wondering if that may somehow be related.

A plumber was under the house installing a cleanout recently, and he did say he could feel the vibration in the pipes when it happened. Ran out of time though, and he wasn't able to troubleshoot.

Thanks for any help anyone can offer.

 

[Dj2]

Are you sure it's not drain related?

 

[Sponsor]

 

[Reach4]

Are you sure it's not drain related?

She says she is.

Her tub filling story would seem to back that up. Weird.

Sondra, can you get a clear sound recording?

 

[Plumber69]

I Wonder if your hearing the pipes expand and contract in the walls

 

[Sondra N]

Hi All.

Thanks very much for your posts.

I've lived in this house for about 30 years now and this sound is new-ish (4 months or so).

Yes, POSITIVE the sound is not from the drains. (Why is this so hard to believe, I wonder?)

Last night, I was reading about hammer drain. The descriptions of the sound hammer drain typically makes are much different than our glub sound, so I didn't really think this would be it. But after reading one of the recommended solutions for that last night, I thought it would be worth a try. I came home today and turned the water off at the main, opened and closed all faucets, then turned faucets back on, one by one. Amazingly, I no longer hear the glub, glub, glub. We shall see if it lasts. Don't really understand exactly what happened there, but YAY! Please keep fingers and toes crossed that this simple, no-cost fix has done the trick! How often does THAT happen??!

If it comes back (boooooooo), I will try my best to get a sound recording. At night, when everything is so quiet, it sounded pretty loud, so I do think it would be possible to record it.

(In case it's significant, we did re-pipe the house with copper 7 or 8 years ago.)

Thanks again.

 

[Reach4]

1. I presume you are on city water. If not, say so.
2. Is there more glub after using hot water than cold water? It appears not from your description.
3. Get a water pressure gauge. See if the pressure indication varies during the glubs. A garden hose thread presssure gauge can go inside on a laundry connection or on the drain for the water heater. Outside it may or may not be different than inside. If it varies inside to outside, that would indicate you have a pressure reducing valve.
4. Do you have a thermal expansion tank? If not, get one if you get any more glub. Don't worry if you need one. If you already have one, knock on it. It should sound empty.

As you have figured out, your symptom is not at all common.

 

[Jadnashua]

One more question...do you have a pressure reduction valve?

 

[WorthFlorida]

When the copper was installed were any water hammer arresters installed? Usually at the washing machine. The old way was just capping off a length of pipe to create an air pocket to act as a shock absorber. Maybe one came water logged and buy draining the system the air did get back into the pipes or a hammer arrestor piston is broken, water was behind the piston and again, draining the pipes put air back into it. There are other types of arresters.