Leaking in-wall lav faucet valve

Discussion in 'Plumbing Forum, Professional & DIY Advice' started by oddjob, Feb 22, 2010.

  1. oddjob

    oddjob New Member

    Joined:
    Feb 22, 2010
    Location:
    Bellingham WA
    I bought a single handle wall mounted faucet for a new bathroom addition. The inlets on the mixer are female. I hooked them up to pex tubing with NPT 1/2" male threaded to 1/2" pex crimp fittings. The threads were treated with pipe dope (Rector Seal #5).

    The system is now leaking from the threaded connections. I think the male fittings may be bottoming out in the mixer body threads before establishing a seal.

    Am I using the wrong kind of fittings?

    Thanks for any input.
     
  2. Terry

    Terry Administrator Staff Member

    Joined:
    Aug 17, 2004
    Occupation:
    Plumber
    Location:
    Bothell, Washington
    Can you post an instruction sheet or picture?

    If they are tapered threads, then the pipe dope would be fine.
    If they are straight cut threads, they may use a flat rubber washer in between.

    But I'm only guessing without a picture.
     
  3. Sponsor

    Sponsor Paid Advertisement

     
  4. oddjob

    oddjob New Member

    Joined:
    Feb 22, 2010
    Location:
    Bellingham WA
    The item came without instructions (risks of ordering from online discounters) and the specs from the manufacturer's web site don't say what standard the threads are.

    I'll try the washers to see if that seals things up.

    Is it acceptable practice to use rubber washers behind the wall where there won't be maintenance access?
     
  5. Terry

    Terry Administrator Staff Member

    Joined:
    Aug 17, 2004
    Occupation:
    Plumber
    Location:
    Bothell, Washington
    It's easy enough to tell if the threads are tapered by looking.
    If they are tapered, then you can't use a rubber washer.
    You might just need to tighten things up.
     
  6. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

    Joined:
    Sep 2, 2004
    Occupation:
    Retired Systems engineer for defense industry.
    Location:
    New England
    If they came with washers, then the threads are very likely not NPT (tapered) and the seal is created by the washer, not in the threads and pipe dope (or tape). You'd need a different connector.
     
  7. hj

    hj Moderator & Master Plumber Staff Member

    Joined:
    Aug 31, 2004
    Occupation:
    Plumber
    Location:
    Cave Creek, Arizona
    The valve WILL have tapered pipe threads. Any "odd" thread will be the PEX adapters, although even they should have the correct threads. You probably did not tighten them properly. Did you follow someone's directions to tighten them hand tight and then an additional turn? If so, that is your problem. You cannot tighten threads to a formula.
     
  8. Winslow

    Winslow Plumber

    Joined:
    Dec 30, 2005
    Occupation:
    Plumber
    Location:
    Hawaii
    If you bottomed out the threads then you either over tightened them or they are not tapered threads. I have run into that on european faucets. If you can hand tighten them all the way in then the threads are not tapered. I use loctite in that situation and it works well.
     
Similar Threads: Leaking in-wall
Forum Title Date
Plumbing Forum, Professional & DIY Advice Shower leaking?? Sunday at 11:10 PM
Plumbing Forum, Professional & DIY Advice Help needed with this unusual leaking sillcock Feb 21, 2015
Plumbing Forum, Professional & DIY Advice Advice wanted on dealing with leaking compression fitting Feb 20, 2015
Plumbing Forum, Professional & DIY Advice Leaking overflow pipe from combo cylinder Feb 18, 2015
Plumbing Forum, Professional & DIY Advice Leaking Fitting Feb 3, 2015

Share This Page