Glug-glug in water supply line

[Grebus]

When water is being used in my house I am hearing a glug-glug sound in the copper supply line close to where it enters the house. I recently had the water heater replaced and the tech also installed an expansion tank. I am thinking there may be some air trapped in the pipes, or is there something else I should check with that type of sound? Thanks.

 

[Reach4]

Air is only temporary.

What do you have in line with your incoming water? Is the water meter in the area of the sound? Do you have a PRV? You could post a picture that includes whatever you see.

 

[Sponsor]

 

[Grebus]

No, it's not near the meter and I don't have a PRV. The copper line comes in from the outside wall (the right side of the first picture), and then there is an old shutoff valve within about 6 feet (on the other side of the wall painted white in the second picture) that has not been disturbed for a long time. There is another shutoff valve near the WH that I believe the tech used to work on the new WH, and he also had to do some minor plumbing to be able to install some new flex lines and the expansion tank. I can also feel a slight vibration in the pipe when I touch it that seems to correspond to the sound.

 

[LLigetfa]

Some water heaters have heat traps in the lines going to and/or coming from the tank. In some circumstances they can make noise and vibrations.

 

[Reach4]

Some water heaters have heat traps in the lines going to and/or coming from the tank. In some circumstances they can make noise and vibrations.

Grebus, do you get that sound when using cold water, or only hot?

 

[Grebus]

It seems to be happening no matter which is being used. I did some reading on heat traps (BTW my new WH is a Bradford White). So if I turn off the shutoff nearest the WH and then run cold water somewhere else, I should not hear the noise if it is being caused by the heat trap?

 

[LLigetfa]

So if I turn off the shutoff nearest the WH and then run cold water somewhere else, I should not hear the noise if it is being caused by the heat trap?

Correct.

 

[Grebus]

I tried turning off the WH shutoff and then ran some cold water elsewhere, but I still hear the same noise.

For what it's worth, I took a look at the little flow indicator on my water meter out at the street and it was periodically moving a little forward and then a little backward. From reading about it on this forum, it sounds like that is somewhat common, but could it have anything to do with the noise?