One of the first things that comes to mind is the fill valve (float valve) inside the toilet tank. Typically, when the valve diaphram (fla rubber gasket) inside the float valve cap goes bad, then the valve starts moaning when it trys to shut off. This is caused by micro vibrations produced as the gasket tries to close against the incoming water pressure. The water is trying to push the gasket away from the opening, and the float as it rises is trying to close the opening. Since the gasket is worn out, it becomes hard like a super ball. Instead of forming softly around the opening, it bounces against the opening. It bounces so fast, it is like the vibrations of a tuba or trumpet player. Because most homes have metal pipes, it sets up a harmonic wave through the pipes that echos through the house. You can test this by simply lifting up slightly on the float rod, when you hear the sound. If it shuts off, you've solved your problem. Then you can replace the whole valve for around ten dollars (easier than trying to replace the gasket on the inside of the fill valve, unless your a plumber).

Good Luck

Raymond VinZant Plumbing Prof

Raymond VinZant Plumbing Prof.

and here's an online tutorial on replacing the fill valve..........

http://www.toiletology.com/replace.shtml

So, the fill valve from the toilet upstairs is what is most likely causing the pipes to moan after we brush our teeth in the morning or use the water to make coffee?

If thats the case I will get right on it :) thanx guys :) !

You can sometimes isolate the exact problem location by operating the fixture's valve while the noise is occuring.......(re: lift the float)

The noise wants to telegraph thru the system confusing the actual location.......