Dishwasher Drain to Disposal Req'd?

Discussion in 'Plumbing Forum, Professional & DIY Advice' started by whizmo, Aug 10, 2005.

  1. whizmo

    whizmo New Member

    Aug 10, 2005
    Hi, while doing a minor kitchen remodel with new sinks and faucets, I discovered the our ten-year-old house was originally plumbed with the waste line from the dishwasher draining directly to the sink waste line (through an air gap) rather than going through a garbage disposal that sits right next to the dishwasher. (The disposal's dishwasher inlet knockout plugs are are still intact, so it's been this way since the house was built.)

    Is this Okay? It's been fine for ten years and I know that if there is no disposal, then this is acceptable, but I'm seeing some reports that a connection to a disposal, if one exists, is required by code and highly recommended.

    I'm in the Seattle area, BTW.

    Last edited: Aug 10, 2005
  2. Gary Swart

    Gary Swart In the Trades

    Sep 1, 2004
    Yakima WA
    Boy, I sure hope it's OK. I don't have a garbage disposal in my house and the DW goes into a tailpiece above the sink trap. Don't have a airgap either, just looped the hose under the countertop.
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  4. Terry

    Terry Administrator Staff Member

    Aug 17, 2004
    Bothell, Washington
    The dishwasher doesn't need to drain to the disposer.
  5. Master Plumber Mark

    Master Plumber Mark Master Plumber

    Feb 6, 2005
    Sensitivity trainer.. plumber of mens souls
    indianapolis indiana - land of the free, home of
    ok but better to

    Its ok, and either way works....

    more a matter of convienance to have
    an easy place to install that dw into

    Though I have always felt that through
    the garbage disposal any large residue
    that might be on the dishes would get a
    little better groundup ....before going down the drain...

  6. jimbo

    jimbo Plumber

    Aug 31, 2004
    San Diego, CA
    Here we almost always see it connected to the disposal, although I don't believe code requires that. The drawback is, if a person tends to leave a lot of food scraps on the plates as they go to the DW, enough stuff in the waste water can clog the grind chamber in the disposer. I had to "train" the misses to try to remember to cycle the disposer briefly after the first wash cycle in the DW.
  7. whizmo

    whizmo New Member

    Aug 10, 2005
    Thanks everyone. If I every rework the plumbing, I'll put it throught he disposal, but for now, I'll let it go and just be sure to scrape dishes well. Appreciate the advice.
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