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Discussion Forum

Overflow from condesate trap

ericmueller | Posted in General Discussion on November 14, 2008 06:41am

Hi All.

I recently installed a Bryant furnace in the crawlspace under my laundry room.  The unit is mounted horizontally with a pump for the condensate.  There is a 2″ PVC line running through the crawlspace that handles the waste water from a utility sink and the washing machine.  I tapped into this line to get rid of furnace condensation by installing a wye in the drain line, cementing a trap on the wye, and then a vertical piece of PVC going up from the trap to a height of 1-1/2″ above the main drain line.  I then routed the 1/2″ vinyl tube from the condensate pump into the open end of the vertical piece of PVC.

The problem I’m having is that when the washing machine drains, it’s causing the trap to overflow.  Did I not extend this vertical piece far enough above the main drain?  Thanks in advance for any advice.

Eric

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Replies

  1. User avater
    Matt | Nov 14, 2008 06:52am | #1

    Here, HVAC condensate lines are drained directly to the outside and are not ever (that I have seen) hooked to the house wastewater system.  Maybe they do it differently elsewhere in the country...



    Edited 11/13/2008 10:53 pm ET by Matt

    1. User avater
      IMERC | Nov 15, 2008 06:27am | #12

      here they are run to the house waste system....

      way to cold too cold to run them to daylight....

        

      Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather to skid in broadside, thoroughly used up, totally worn out, and loudly proclaiming<!----><!----><!---->

      WOW!!! What a Ride!Forget the primal scream, just ROAR!!!

    2. losh | Nov 16, 2008 01:03am | #16

      Different jurisdictions have separate requirements for the acidic condensate drain from a condensing furnace (I assume that is what he bought).

  2. DanH | Nov 14, 2008 07:06am | #2

    Yeah, I had a similar problem with a similar installation until I raised the end of the standpipe about a foot. The problem is exacerbated by soap scum buildup in the drain pipes.

    The only function of economic forecasting is to make astrology look respectable. --John Kenneth Galbraith
    1. User avater
      Matt | Nov 14, 2008 03:04pm | #5

      Maybe just letting it run outside is a southern thing?  I could see where having the exterior portion of the drain freeze-up could be an issue?   Here it's mostly just for AC anyway...

      1. DanH | Nov 15, 2008 03:23am | #10

        Yep, too much danger of the condensate drain freezing up in the winter, and besides which you don't want to drain that much acidic water onto the lawn.
        The only function of economic forecasting is to make astrology look respectable. --John Kenneth Galbraith

  3. User avater
    popawheelie | Nov 14, 2008 07:12am | #3

    I always have a pipe at least a foot up from the trap. It's just insurance since I've never had a problem.

    You're already lifting the water with the pump so just lift it further.

  4. User avater
    Sphere | Nov 14, 2008 10:13am | #4

    There are a  few folks here that can help you, but they have been silenced by the moderators, so, all ya get is slap dash advice from people less smart than you, run, forrest, run.

    Spheramid Enterprises Architectural Woodworks

    Repairs, Remodeling, Restorations

     

    They kill Prophets, for Profits.

     

     

    1. User avater
      jonblakemore | Nov 15, 2008 02:11am | #8

      "There are a few folks here that can help you, but they have been silenced by the moderators, so, all ya get is slap dash advice from people less smart than you, run, forrest, run."

      I was tempted to point out that you're still here, and what that says about you.

      Then I realized I am as well, so I guess we're in the same boat. 

      Jon Blakemore RappahannockINC.com Fredericksburg, VA

      1. User avater
        Sphere | Nov 15, 2008 02:30am | #9

        I guess we need to row the boat then. (G)Spheramid Enterprises Architectural Woodworks

        Repairs, Remodeling, Restorations

         

        They kill Prophets, for Profits.

         

         

  5. MikeHennessy | Nov 14, 2008 04:06pm | #6

    A clasic example of why you need to properly vent a trap.

    What's happening is that your washing machine is pumping water so fast that it's pressurizing the line, causing the water in your condensate trap to blow out. You can solve it by either installing a vent between the condensate trap and the line, or making the riser taller so the water doesn't overflow when it gets blown out. However, the using latter method means you may get some sewer gas blowing through when using the washer and it's likely illegal to boot, since the trap is not vented.

    Mike Hennessy
    Pittsburgh, PA

  6. Hiker | Nov 14, 2008 04:15pm | #7

    Here you have to run the condensate line to a sink and install a wye  before the trap.  If you have a pump, you probably can get to a sink and do the same.

    Bruce

  7. User avater
    PeteDraganic | Nov 15, 2008 06:20am | #11

    I've never seen an ac waste line tied into a drain.  they usually let out into a drain but are never connected solidly.  there should be an air gap between the ac waste line and the sanitary drain.

     

    I refuse to accept that there are limitations to what we can accomplish.        Pete Draganic

     

    Take life as a test and shoot for a better score each day.          Matt Garcia

    1. losh | Nov 16, 2008 01:07am | #17

      I think the question dealt with a condensate line from a condensing furnace (High Efficiency). There was no reference to an air conditioning condensate drain in his post.

    2. User avater
      CapnMac | Nov 16, 2008 04:56am | #18

      I've never seen an ac waste line tied into a drain

      And here, it's mandated by code.

      A-coil drain is required to be wet-vented into closest sanitary stack .  Pan (condensate) drain is to go out in an "obivious location"--which means, usuallly, through the soffit in front of a window or door, so it can be seen if dripping.

      But, that also comes from being in a 6-7 month cooling climate, too.

      Dripping past a window or door makes some sense on the an drain, if that is leaking, then the a-coil is probably rusted through.Occupational hazard of my occupation not being around (sorry Bubba)

  8. User avater
    IMERC | Nov 15, 2008 06:28am | #13

    stand pipe needs to be taller....

     

     

    Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather to skid in broadside, thoroughly used up, totally worn out, and loudly proclaiming

    WOW!!! What a Ride!
    Forget the primal scream, just ROAR!!!

  9. Stuart | Nov 15, 2008 06:51am | #14

    How about routing the condensate line right to the laundry sink and capping off the new section you installed?  That's how it was done for my furnace.  Those pumps usually have enough head to pump the condensate six feet high or so.

    1. ericmueller | Nov 15, 2008 05:06pm | #15

      Thanks to all for the replies and suggestions.

      The crawlspace has a concrete floor, is insulated, and heated (via the new furnace) so freezing is not an issue.  Routing the condensate pump line to my utility sink would be a major ordeal, so that's why I originally tapped into the drain line.  Fortunately, I can get to the existing vent stack, so my current thought is to place a vent line between the trap and the drain line, and then tie that vent into the existing stack.  I'm also going to extend the height of the standpipe leading into the trap so that it's at least 8" above the drain line (if the joist space will allow a bit more height, I'll use it). 

      Eric

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