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Thud or thumping sound at kitchen sink

Fizz Member Posts: 547
What causes a thud or thumping sound when turning-on kitchen faucet?


  • ChrisJ
    ChrisJ Member Posts: 15,149
    Hot water causing copper pipe to expand and rub against a floor joist or stud in the wall?

    Pretty vague question. :(
    Single pipe quasi-vapor system. Typical operating pressure 0.14 - 0.43 oz. EcoSteam ES-20 Advanced Control for Residential Steam boilers. Rectorseal Steamaster water treatment
  • Fizz
    Fizz Member Posts: 547
    It occurs on turning on cold water, and is more pronounced when water has been off for a period of time.
    JUGHNE Member Posts: 10,898
    Water hammer....do you have a back flow preventer/check valve on your water service?
  • hot_rod
    hot_rod Member Posts: 20,725
    It could be the small plastic diverter check valve inside that engages when you use the spray hose on some faucets.

    If it has a spray hose try flicking that on and off when the faucet is running.
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
    rick in Alaskamattmia2kcopp
  • Fizz
    Fizz Member Posts: 547
    Don't know if service has back-flow preventer. Will try Hot Rod's suggestion. Thanks to all!
  • MichaelK
    MichaelK Member Posts: 34
    Another trick to solve this is to install an air arrestor in the line. You can purchase pre made or just shut the water off to your house drain the line and install a tee in the line. Extend a pipe up 3 or 6 inches, and cap it. Turn the water back on and your done.

    Sometimes in restrooms you may notice a capped line next to a urinal extending up from the main water feed. Same idea.

    It might be you have high water pressure in your home. If it's what I'm thinking it should be several quick thus upon turning on the water that deminish the longer it's running. Sometimes a thud when you shut the valve as well.
    Michael Knight
  • Mark Eatherton
    Mark Eatherton Member Posts: 5,840
    edited March 2016
    Try pulling the rinse hose completely out of the sink and see if it jumps when opening or closing the faucet. Mine does.

    It's not so much a case of "You got what you paid for", as it is a matter of "You DIDN'T get what you DIDN'T pay for, and you're NOT going to get what you thought you were in the way of comfort". Borrowed from Heatboy.
    JUGHNE Member Posts: 10,898
    On some new faucet installs sometimes the rinse hose would act up. I would pull out the hose, turn the water on and just squeeze the sprayer enough to get the spray diverter to "machine gun" chatter. This would loosen up or flush the diverter. Not sure what it did but kept me from having to take apart a new faucet for nothing. FWIW
  • MikeL_2
    MikeL_2 Member Posts: 470
    edited March 2022
    Home made water hammer arrestors will not last very long, the water will absorb the air in a few days....
  • SteamingatMohawk
    SteamingatMohawk Member Posts: 867
    Unless there is some kind of internal bladder, any air pocket will eventually get absorbed in the water. Nice try.
  • Intplm.
    Intplm. Member Posts: 1,603
    Is it a rapid repeating sound type thud? If so, you have a loose washer at the faucets' cold or hot water seat.

    If it's happening when a spray hose is used, very often this occurs because the trigger on the sprayer isn't being pushed down completely. ( This depends on the type of faucet.)

    Lastly. If this is happening when you quickly turn the faucet on and off then you are experiencing water hammer. This can be corrected by installing a water hammer arrestor.
  • Fizz
    Fizz Member Posts: 547
    It's a single thud that happens with either the hose or handle on faucet...and doesn't happen if you turn handle of hose on and off multiple times in shortened time frame. If I turn-it-on slowly then it sometimes won't occur.