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Weird Noise from 3/4" Wilkins 350XL Double Check Valve

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FredoSP
FredoSP Member Posts: 122
edited July 17 in Plumbing

Hi All,

A couple of days ago I had my annual backflow device tested and it passed, no issues. Today I started to hear this strange humming noise coming from the basement when I turned on the kitchen faucet. I then tested the upstairs sink faucets, same noise. I tracked down the noise to be the backflow device. To me it sounds like air is trapped? The noise goes away when the faucet is shut off. Can anyone give me any suggestions on what to do? The backflow device could be ten years old, maybe its end of life?

3/4" Wilkins 350XL Double Check Valve Assembly (Lead Free)

I have uploaded a 7 second video of the noise.

LINK TO VIDEO

IMG_3511.jpg
Long Island, NY

Comments

  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 10,765
    edited July 17

    I find that most humming happens when they forget the words. If you can find the proper sheet music with the right lyrics, the humming will stop.

    Edward Young Retired

    After you make that expensive repair and you still have the same problem, What will you check next?

  • EBEBRATT-Ed
    EBEBRATT-Ed Member Posts: 18,221

    @FredoSP

    Maybe open every faucet in the house wide open and run it a little.

  • hot_rod
    hot_rod Member Posts: 25,332

    did they rebuild it or just a test and recertification?

    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • FredoSP
    FredoSP Member Posts: 122

    Thanks Ed but that didn't change anything.

    They just did the annual test that's required by my local water authority. I was in the basement watching. One guy was holding a flavor flav inspired gauge and a line or two was connected to the backflow device. The other guy was entering the numbers in the iPad. It was not making this noise before or during the test. I only noticed this later on in the day after they left.

    Long Island, NY
  • Intplm.
    Intplm. Member Posts: 2,674

    On your device, you have three test cocks. They are the small valves with the little black plugs. Remove the plugs and, one at a time, run water through the test cocks. Let it run…spray, for about five seconds or more. See if that helps remove the noise.

    If that doesn't help, check to see if a hanger/support supporting the device is loose or missing.

  • FredoSP
    FredoSP Member Posts: 122
    edited July 19

    Thanks for the suggestion but it didn't do anything to help with the noise.

    I'm wondering if something internally has failed or is worn out. I looked through my receipts and found this device was installed in 2014, so maybe something like an o-ring or one of the springs inside the check valves are acting up, or even sand or a small pebble made its way in?

    It looks like I can purchase a new housing assembly that has the two checks and o-rings. It's a fraction of the cost of replacing the whole thing. What do you think?

    wilkins_1.jpg
    Long Island, NY
  • Intplm.
    Intplm. Member Posts: 2,674

    If you have found the direct replacement part and the noise is that much of a nuisance, why not replace it? If nothing else has worked and you a confident that the valve is the source of the noise? Why not.

  • hot_rod
    hot_rod Member Posts: 25,332

    there really is not much inside, two self contained spring checks.

    Very easy to disassemble and clean, but you do loose the certification if you tear it down.

    I would have the two replacement checks on hand if you open it up

    IMG_0672.jpeg
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • FredoSP
    FredoSP Member Posts: 122

    Thanks guys. I ordered the replacement today and will report back once its installed.

    Long Island, NY