Singing water pipes

[Carson Dyle]

This is an intermittent problem we've had for the past several years.

I live in a duplex with one water service/meter feeding both residences. Also, one sprinkler system that services both yards. In both residences when we open a faucet, sometimes we'll hear a very loud humming/squealing vibration sound coming from the pipes. It's pretty nasty. Sounds like something will blow if it isn't stopped within a couple of seconds. Usually we can simply close the faucet and open it back up again immediately and the noise is gone. Lately, though, it's gotten worse, to where it sometimes takes two, three, even four open/close cycles. After it happens, it then doesn't happen again for a time period ... maybe an hour or two between incidences.

As best as I can remember, this only happens in the winter, when the sprinkler system is turned off. That usually happens in October, and the system is blown out with air. It gets turned on again in late May.

It only happens when we open kitchen or bathroom faucets, either hot or cold water or both. I don't think it's ever happened when flushing a toilet or opening the tub/shower faucet.

We had an issue with very high water pressure here about ten years ago that burst a pipe, so had a pressure relief valve installed. I haven't had the pressure tested in recent years, but wouldn't be surprised if it's crept up again. We have great water pressure.

Any ideas what's going on, and where the problem may be? I suspect it's caused by air in the pipes, although I don't understand how it would be cleared just by closing/opening the faucet again. Could it possibly have something to do with the sprinkler system, like maybe a bad backflow prevention valve?

 

[C1]

Classically the cause is a loose washer in one of the faucet valves. Since it's only kitchen or bath then these may be using a single mixer type valve in each case.

Rebuild the kitchen mixer valve & see what happens (not that hard to do).

Also, if water pressure is that high (that a pipe was blown), then you probably should install a pressure regulator off the main (city?) line.

All homes need to have them locally here as the street line pressure is 120 psi and it has been recorded to intermittently increase to as high as 150/160 psi on occasion. (The issue is that as an area grows; ie, more homes added, the city pressure needs to increase to accommodate the required volume/demand.)

 

[Carson Dyle]

I said a pressure "relief" valve was installed a few years back. I suppose I mean a pressure regulator. All of the faucets in my place, including the shower, have both hot and cold water handles. I'll have to check next door.

 

[C1]

Separate faucets makes more sense that loose washers could be the cause of singing.

Disassemble one of the faucets that demonstrates the singing and change out the washer and see if that results in a change for the better.

 

[Carson Dyle]

This got bad enough last week that we finally broke down and brought in a plumber. Turned out it was the pressure regulator. Even while on the phone, the plumber speculated that was the problem. Odd thing is that the regulator is installed in the neighbor's basement, where the water comes into the duplex, yet in all the time this has been an annoyance, they never identified the source of the noise.