Forum Discussion

philh's avatar
philh
Explorer II
May 08, 2019

Still battling water pump issue

Dealer fixed the issue with water coming in from the onboard tank. According to their report, filter was blocked. BS, the winterizing suction tube worked fine and the shut off valve is now in the system with hose clamps... so that was at least removed by the dealer.

Now, I've got water hammer so bad that something is likely to break. Found no o-ring to seal the filter to the pump, added an o-ring. Did not change the behavior.

This may be an important observation, while the water hammer is undergoing, the LED lights are flickering.

It's 150 miles one way to the dealer, and I'm more than a little frustrated.
  • wopachop's avatar
    wopachop
    Explorer
    May 09, 2019
    Could there be a water bubble stuck in the pump? Could loosen the pump screws and tilt and shake the pump while it runs maybe?

    Or possibly a slight air leak on the intake side? Like when a straw has a crack and introduces air.
  • philh's avatar
    philh
    Explorer II
    May 09, 2019
    This isn't a pipe rattling issue or vibration, this is a serious water hammer issue that will break something. Doesn't matter which faucet is run, the problem persists.
  • opnspaces's avatar
    opnspaces
    Navigator II
    May 09, 2019
    philh wrote:
    Dealer fixed the issue with water coming in from the onboard tank. According to their report, filter was blocked. BS, the winterizing suction tube worked fine and the shut off valve is now in the system with hose clamps... so that was at least removed by the dealer.

    Now, I've got water hammer so bad that something is likely to break. Found no o-ring to seal the filter to the pump, added an o-ring. Did not change the behavior.

    This may be an important observation, while the water hammer is undergoing, the LED lights are flickering.

    It's 150 miles one way to the dealer, and I'm more than a little frustrated.


    When you say water hammer are you referring to the pump pulsation noise when it's running? Or are you referring to a hammer noise when you close the faucet and the pump stops?

    If you're referring to the pump pulsations I would guess that the dealer inadvertently moved a PEX line against something. Maybe try turning on the outside shower so the pump runs but doesn't fill a holding tank. While the pump is running reach in around the pump and move the PEX lines to see if the noise changes. If you can silence or minimize the noise then use a piece of foam or Styrofoam to hold the lines in this position.
  • maillemaker's avatar
    maillemaker
    Explorer
    May 09, 2019
    My LED lights also flicker when my water pump is on. I used to see the old incandescent dim slightly when the pump was on, but with the LED replacements they flicker. I suspect this is because of the cycling drop in voltage due to the pump - the electrical system has not been designed to provide even voltage to the light fixtures to keep the more-sensitive LED lights happy. I suspect future RVs will have to isolate the power to the pump somehow.
  • DFord's avatar
    DFord
    Explorer
    May 09, 2019
    Another thought is there's supposed to a pocket of air in the water heater to allow expansion of the water as it's heated. Try completely draining the hot water tank and refilling it. That will renew the air pocket and should help with any water hammer.

    If the pump is "hammering" while it's running, it's probably because the water lines to or from the pump are rattling against the walls of the wet compartment. See if you can reposition those lines to stop the noise. A pad of some sort might help between the wall and the water line at the point of contact.
  • philh's avatar
    philh
    Explorer II
    May 09, 2019
    Pump did not hammer before dealer "fixed" the tank flow issue.

    All the air had been previously purged using municipal water.

    i have not tried multiple faucets open, but hot and cold together lessens the impact.
  • YC_1's avatar
    YC_1
    Nomad
    May 09, 2019
    New to you unit?
    Did it always hammer?

    This hammering is very common and there are kits to calm them down. They can make a great deal of noise in some installations.

    Example of a cure

    There are kits sold that come with a couple of hoses to make the intake and output lines flexible. If Pex is connected directly to a pump it can really machine gun the whole rv.
  • shastagary's avatar
    shastagary
    Explorer
    May 09, 2019
    sounds more like the pressure switch at the pump going on and off as the system comes up to pressure that would make the lights flicker.
    have you opened all faucets and gotten all the air out of the system? that could cause the pump to cycle on and off rapidly as it gets up to pressure.

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