Our pipes began making noise about a week ago. The noise comes on for varying lengths of time; from as short a period as 5 seconds to as long as 5 minutes. The noise is mostly between 7pm and midnight, however we sometimes get the noise in the middle of the night and early in the morning.

We have a main cut-off at the point where the line enters our house. Next in line is the water meter, and then we have a second cut-off. If I fully close the 2nd gate valve (the one after the meter) I can still hear the noise in the section of the line between the main cut-off and the 2nd cut-off. So I do not think that the problem is related to something inside our house.

The noise sounds like water moving inside the pipes, but a very rough movement. It also causes the pipes to vibrate very strongly. The section of piping between the two values is about a 3 foot vertical climb and a 2 foot horizontal run. So when I turn the 2nd valve off it is fairly easy to pinpoint the area of the noise.

We have had the water company come out twice at night and their explanation was that it is "air in the line". However it doesn't seem like air should be moving if water isn't flowing.

We have two toilets, both have fluid master valves, however I am fairly certain that neither one is leaking. Again, when I cut off the water to the house I still hear the noise.

We are baffled.

I called a plumber out today to replace the main cut-off valve (the first one in my series) because it wasn't working. We don't expect that to fix the problem, however we are hoping that if we can cut the water at that point, at least the pipes won't vibrate in the pipes between it and the 2nd valve. He was also baffled.

Does anyone have any thoughts or suggestions?

-craig

Put food coloring in the tanks in both toilets and prove its not leaking... I'll bet at least one is. In a few hours or less you will see the dye in the toilet bowl if it is.

I like to do it before you go to bed and check it first thing in the morning... or when you leave the house for a few hours where nobody will be home to use them.