I've been hearing running water sound in the walls for the past few weeks. Sounds like someone is taking a shower. We have no water meter. We do have a main shut off in the basement. When I shut off the main valve the sound stops.

The main water pipe goes to the water heater, kitchen sink, bathroom sink, bathroom tub and to the laundry room. We have an outside faucet but we have that shutoff.

We see no running water anywhere. There is a slight, I mean slight leak in the shower. About 2 cups an hour comes out. We are going to replace that when we re-do the shower in a few months.

Any ideas? It's a small house and we can see all the pipes.. Puzzling.

Are you on a well or city water? Try closing the stop valves under every toilet, does that make a difference?

City water supply.. We are charged a flat per family fee.

Where is this? Try closing the toilet stop valves.

When testing I completely turned off water to toilet and sound persists..

In order for sound to be coming from toilet it would have to be filling up? Like after you flush? Or can water escape in toilet without the ball dropping andthat allowing the water to turn on?

A toilet can have a very slow leak in the flapper and you will not notice any change in water but it will be constantly draining, slowly. Now I want to make one more request of you. Shut off the water to the toilet tank and then flush the toilet. Wait 5 minutes and see if the sound is gone. If the sound disappeared I'd venture to say you have a slow leak in your flapper.

I'll test and let you know.. Thanks.