Shower plumbing question

Discussion in 'Shower & Bathtub Forum & Blog' started by mrmichaeljmoore, Jul 16, 2007.

  1. mrmichaeljmoore

    mrmichaeljmoore Member

    Messages:
    128
    Location:
    Connecticut
    Installed a new bathroom shower faucet set...
    It is a single handle faucet with the plunger on the downspout.

    Now here's the issue: If I turn the water on, water will run out out of the downspout, as expected....but after a few moments water will also begin coming out of the showerhead. Now, it is more than a drip. I would say the water comes out at about a 1/4 of its normal shower flow.

    My wife was trying to give our daughter a bath and she was getting soaked as the water poured out of the showerhead.

    I checked the downspout to see if there was something wrong with the plunger. It seemed to be fine.

    Any ideas why water would pour out of the shower head when the plunger is down??

    Thanks.
  2. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

    Messages:
    22,269
    Location:
    New England
    Using the wrong size pipe for the showerhead or spout, or using the wrong outlets from the valve can cause that. On some valves, they say to cap one outlet on the valve...using both can cause that. If the internal pipe diameter is too small, it can't flow properly, and the backpressure forces some out the showerhead.

    What kind of pipe and what size are the spout and showerhead plumbed with? Are you using both the top and bottom outlets? What kind of valve and model is it?
  3. mrmichaeljmoore

    mrmichaeljmoore Member

    Messages:
    128
    Location:
    Connecticut
    As far as the sizes of the pipes, I'll have to double check. I dont recall off the top of my head.

    The thing that is weird, is that I mererly replaced what was there. The old shower head was Moen and the new was Moen....
    It was just putting a new one because the old fixture/showerhead was corroded and didnt match the new sink fixture...

    I don't believe there was anything different between the two models.

    Heres a link to the Lowes page with the fixture:
    http://www.lowes.com/lowes/lkn?action=productDetail&productId=27418-000000866-82246&lpage=none
  4. markts30

    markts30 Commercial Plumber

    Messages:
    630
    Location:
    Phoenix, AZ
    What type of pipe did you use?
    If your old was 1/2" copper and you replaced using 1/2" pex, you might have restricted the flow through the tub spout...(1/2" pex is smaller ID than 1/2" copper)
  5. AlwaysInHotWater

    AlwaysInHotWater New Member

    Messages:
    25
    Location:
    California
    A quick 'almost' fix would be a flow control valve behind your shower head. Most valves are not 100% shut-offs but it would at least reduce the shower head flow down to a drip or minimal trickle.
  6. Alectrician

    Alectrician DIY Senior Member

    Messages:
    689
    Let me know when you find out why. I have the SAME problem. Everything is 1/2" copper on mine.



    I HATE plumbing and it apparently hates me.
  7. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

    Messages:
    22,269
    Location:
    New England
    I'll say it again, some valves are not designed to use both the upper and lower outlets, even though it seems counter intuitive. You need to read the instructions carefully to see if your valve works that way (sounds like it). One some of them, you MUST plug one of them, then use a T fitting to get the shower output when the spout divertor is turned on. failing to follow those instructions will lead to flow out both ports when you only expect it out of the spout.
  8. Alectrician

    Alectrician DIY Senior Member

    Messages:
    689


    I didn't read the instructions but the valve said "shower" on the top and "tub" on the bottom.
  9. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

    Messages:
    22,269
    Location:
    New England
    That still isn't a vindication for your installation! Some of the valves say only use one port. The other one must be plugged. The manufacturer often sells the valve for a shower only, or tub only or both. the markings may only be to help in orientation.
  10. now i get it. Why the markings "stay" for the situation when there are both. No need to rub them off, except that they risk confusing less experienced people. Wait a minute, i think that is a good reason not to leave those markings, if they sell to DIY...

    david
  11. BAPlumber

    BAPlumber Plumber

    Messages:
    227
    Location:
    Vashon, Washington
    i'd be interested in what brands your talking about. I've never heard what your saying before.

    Brent
  12. Alectrician

    Alectrician DIY Senior Member

    Messages:
    689

    I'll go open a new box at the "store" and read the printed instructions. If the differ from the implied instructions on the set, I'm gonna get all riled up.
  13. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

    Messages:
    22,269
    Location:
    New England
    As noted in my sig line, I'm not a professional plumber. But reading on here for several years...it has been mentioned by some of the pros that you can't use both ports on some valves. Plus, anything that restricts the flow can cause the water to flow out the shower head even when the divertor on the spout is not pulled up.
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