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off topic,plumbing ?

jonny88 Member Posts: 1,139
hi,im having a problem with two houses.when the tennant runs water im getting a constant knocking sound going thru pipes.tried an expansion tank and air champers,do you think it is possible that the meter could be causing the problem.thanks


  • j a_2
    j a_2 Member Posts: 1,796

    1   Two different houses?

    2   incoming pressure   30 min    80  max? 

    3   recent work?

    4   Banging when, turn on,turn off,hot,cold?

    5   Fixture bypass?

    6   prv installed?
  • Paul48
    Paul48 Member Posts: 4,470

    it a machine gun noise? Or, a bang on closing?
  • jonny88
    jonny88 Member Posts: 1,139
    banging pipesd

    house no.1.65psi no prv.when domestic water is running banging isnt very noticeable but they have a lawn inground sprinkler system installed to.sprinkler has a watts backflow.when water for sprinkler kicks on banging increases to the point where you can hear it thru entire house.i told him to call irrigation guy ,maybe a solenoid valve?but why is there banging when sprinkler is not running.

    house no2 psi50. banging like the other house occurs when using domestic water ,not to loud but it is there.someone said to me maybe meter is undersized or maybe a washer inside it is bad?do you think taht makes sense.thanks for your input
  • jonny88
    jonny88 Member Posts: 1,139
    machine gun

    m-16 on automatic
  • Larry Weingarten
    Larry Weingarten Member Posts: 2,284
    Try a little testing.

    Run only hot water; one, two, three taps and see if/when you get the noise.  Do the same for cold water.  It's a way to narrow down where the problem lives.  Let us know what you find.

    Yours,  Larry
  • icesailor
    icesailor Member Posts: 7,265

    Where I work, the meters that the municipal water company would wake the dead.

    If the noise is loudest where the water enters the house, stop the water. There should be no banging. If you flush a toiler, it should start. As the tank fills, and it gets to filled, the noise should slow down and stop. Turn on another faucet like an outside hose. It should be a fast banging. I hear them when I fill water heaters that sound like "WRRRRRR". You can't hear the bang.

    The water company where I work sort of ignores the problem because a new meter will be just as loud.
  • Mad Dog_2
    Mad Dog_2 Member Posts: 3,471
    Beware of.......

    loose pipes in the wall and ceilings...u can put in all the water hammer arrestors you want...and it won't solve the problem  Mad Dog
    To learn more about this professional, click here to visit their ad in Find A Contractor.
  • Zman
    Zman Member Posts: 6,983

    With no PRV at the meter I would use a gauge that records the high (little red needle) You may be seeing much higher spikes. I assume you have checked for rogue check valves that may be trapping pressure. The other posts are good suggestions as well.

    "If you can't explain it simply, you don't understand it well enough"
    Albert Einstein
  • Speculator
    Speculator Member Posts: 1
    Just some thoughts

    My initial thought is that you probably received your information about the water meter being #1 suspect from a local person either a plumber/repair person or the water company. This may be one of your best clues because local people will be best acquainted with local issues. How is it that you have two houses on one meter? If this is true then you have a common water service feeding both houses and that also suggests the water meter or shut off valve/check valve/back flow prevention device at or near the meter or somewhere in the common water service line is at fault. I am guessing here, but house #2, since it is lower pressure, must have a PRV. This takes it down to only 50 psi and that may be a reason the noise is less with this house than house #1. If you want to solve this issue without changing the water service, I would probably start at the house #2 and adjust the pressure down to about 35 psi (if you can still get a good shower at that pressure) and see what that does to the noise. Older houses with older piping may not be able to go that low and still serve the needs of the occupants. However, if this helps solve the problem, you may be onto something and provide some more information for us to help you solve your plumbing problems.
  • jonny88
    jonny88 Member Posts: 1,139
    seperate locations

    sorry i wasnt clear,houses in different locations.thanks for all your input i will use your suggestions this week and get back.
  • Mark Eatherton
    Mark Eatherton Member Posts: 5,837
    Toilet float arm style ball cock...

    I have had situations whereby the float and arm style of ball cock on a toilet will bounce upon a pressure drop, setting up a shock wave that persists until water pressure increases, and allows the float to close off against its seat.

    Close off the supply to all toilets, or go around when the hammering is occurring, reach in and lift up on the ball arm and see if it stops.

    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.
  • icesailor
    icesailor Member Posts: 7,265
    Meter Redux:

    For what it may be worth to you and others, Water Companies, in their never ending effort to eliminate living help that they actually have to pay wages to, are automating their metering systems. Older meters (Badger was one) worked with a paddle going back and forth in a chamber being filled with water. The paddle was connected to a gear set that ran the measuring wheels. It had to be read manually so they used to read every few months. Now, it is done magnetically.

    Where I work, they are on the leading edge of meter reading evolution. They use meters made by a company named Sensus. They are world leaders in fluid measuring. With their ability to do remote reading, they don't ever need to take the cover off a meter pit. They now are able to read your meter every 15 minutes and chart your usage 24-7. The only problem is that these high tech meters knock like an old Checker or Yellow Cab with the spark retarded and the engine trying to knock the pistons out the side of the block.

    If you have this same problem, you will have to learn to live with it. If it is the same problem, it has absolutely nothing to do with the mechanics of the system. They all do it. Some worse than others and some more noticeable than others.

    Where I work, 95% of meters are outside in pits. Very few are inside buildings. Even the ones inside buildings knock and it is hard to pinpoint where it is coming from. But it is the meter.
  • jonny88
    jonny88 Member Posts: 1,139
    got it

    thanks for your help to 1 with sprinkler system.i bypassed meter and let water run,no banging.....hooked up meter again and there was banging,told customer to contact water authority,house 2 bad float on toilet,did as ME said and got the sucker ,changed fluidmaster, and no banging,thanks again
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