Dual sinks wont drain

Discussion in 'Plumbing Forum, Professional & DIY Advice, Tips & ' started by alex1000, Jan 28, 2007.

  1. alex1000

    alex1000 New Member

    Messages:
    4
    Hello,
    While I'm pretty handy around the house, plumbing is pretty new to me.

    I replaced a 60" single sink vanity, with two 25" vanities. Now after everything is hooked up, neither sink will drain the water at all it seems. My configuration is as follows:

    -One 1 1/2" P trap right in between the two vanities, leading into the wall.
    -Above the P trap I put a center split waste pipe (looks like a "T"). The top of the T sits about 4-5" higher than the pipe coming out of the wall.
    -From the T split, there are about 18" to each sink drain pipe. There's not a big pitch from the sinks to the center waste, just a very slight one.

    Any ideas on what I can do to fix this? I was reading that some people put a p trap under each sink. Is this the better solution?

    Thanks.

    Alex
  2. plumber1

    plumber1 Plumber

    Messages:
    1,423
    Location:
    Florida
    Clean the drain to the vent pipe.
  3. hj

    hj Moderator & Master Plumber Staff Member

    Messages:
    26,472
    Location:
    Cave Creek, Arizona
    sinks

    If one sink drains into the other, then you have a drain stoppage and you have to clean the drain all the way to the stoppage, not just to the vent.
  4. plumber1

    plumber1 Plumber

    Messages:
    1,423
    Location:
    Florida
    OK.............follow your nose.............
  5. casman

    casman New Member

    Messages:
    78
    Location:
    New York
    I read another similar post last week and it seems to obvious that everytime someone changes to a double sink configuration and neither sink drains that its a clog. Wouldn't this mean it was blocked before the change, or is any partial blockage magnified by adding another sink? Of course I get it that it's most likely a blockage cause otherwise the water would drain but are there any other possibilities besides the obvious?
  6. ddmoit

    ddmoit New Member

    Messages:
    52
    Location:
    SE Tennessee
    With only one P trap, is it possible that each sink acts like a misplaced vent for the other? It might explain why one sink can manage to get past an obstruction, but two sinks cannot.
  7. alex1000

    alex1000 New Member

    Messages:
    4
    with one sink it drained fine. So Im assuming its not a clogged drain issue. But I'll check that...hopefully ill find the drain is to the vent pipe :)

    What about trying two p traps, one under each one?
  8. plumber1

    plumber1 Plumber

    Messages:
    1,423
    Location:
    Florida
    You almost always should clean the drain when you do work like that before you connect every thing back up. And it's a good idea to put a clean out in there while redoing the piping so you can do a good job of cleaning the drain line. It saves a mess too..........
  9. alex1000

    alex1000 New Member

    Messages:
    4
    ok, well...it is definitely clogged. I removed the PVC piping, stuck a 20 dollar snake into the metal pipe in the wall, and the snake goes about 20 inches and is blocked by some muddy/sandy substance. The metal pipe also makes a 90 degree left turn right where I believe it is clogged. But Im having a very tough time breaking thru it. Is there a better tool i should get (assuming the problem is only a couple of feet from the wall)?

    I then connected the standard wall pvc pipe, attached to a 10" PVC pipe directed upward. Filled it with about half a gallon of water before i could see the water stuck in the pvc pipe...which confirms the clog.

    Will pouring boiling water (very carefully! :) ) down the pipe do anything to help?

    Thanks for the suggestions/comments.
  10. hj

    hj Moderator & Master Plumber Staff Member

    Messages:
    26,472
    Location:
    Cave Creek, Arizona
    snake

    A $20.00 snake is probably about useless.
  11. alex1000

    alex1000 New Member

    Messages:
    4
    that it is, other than identifying where my clog is ;)
    i'll probably take it back. Are the more expensive snakes any better? The metal "cord" didnt seem much weaker than more expensive alternatives.
  12. plumber1

    plumber1 Plumber

    Messages:
    1,423
    Location:
    Florida
    Your snake is almost useless, but I bet some of these guys could make it work in a real pinch. It's got to be cable and not a steel tape.

    You need a snake that is a little bigger diameter, a little stiffer, and just keep practicing till you get around all those corners.
  13. leejosepho

    leejosepho DIY scratch-pad engineer

    I have occasionally used water pressure to clear drains, and once they are clear, I sometimes alternate back and forth between cold and hot water to try to help loosen sticky stuff on the walls. There are many ways to get water pressure into a drain line, and those ways might be limited only by imagination! Here are a couple of devices I have used ...

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