My in-laws are hearing running water when inside their shower. I turned off the main and bled the lines and it stops. When the main is back on, the sound is back. So I'm sure it is a water leak either in the wall or under the slab. Unfortunately, both sides of the wall where the sound is coming from are tiled. If I remove the shower faucet, that will give me a small access to the inside of the wall, but it is too small to see very well. Is there any way I can probe down to determine if the leak is in the copper ging from the slab up?
What I want to do is make certain it is an under slab leak before I have someone come out and re plumb the entire house.
Thanks in advance.