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Discussion Forum

Are Dishwasher Air Gaps really Needed ?

| Posted in General Discussion on April 22, 2005 02:10am

I am curious about the need for “Air Gaps” that are required in California for all dishwashers regardless of manufacture instalation requirements.  I just had an inspector refuse to sign off on a kitchen remodel because of no “Air Gap”.

The Bosch Instruction manual states:

“If no air gap is used and the drain line is run into a sink or disposer, the drain line must be elevated to a point higher than the highest water level of the sink to prevent back siphoning into the dishwasher.”

Any and all comments or suggestions would be greatly appreciated.

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Replies

  1. DanH | Apr 22, 2005 03:53am | #1

    The requirement for air gaps varies by jurisdiction. No modern DWs really need them, AFAIK.

  2. calvin | Apr 22, 2005 05:08am | #2

    Here in NW Ohio, never have had a plumber install nor an inspector require.

    Remodeling Contractor just outside the Glass City.

    Quittin' Time

  3. HeavyDuty | Apr 22, 2005 05:27am | #3

    Tough luck Jim, only in California? May be you should move. :)

    Air gaps are required in some jurisdiction but as the above poster said I haven't heard of any problem if the DW discharge is looped high up under the counter.

  4. User avater
    DDay | Apr 22, 2005 03:34pm | #4

    I wonder if the lack of an air gap "Is known to cause cancer to the state of California", it seems like everything in the world is a problem with the state of California.

    Like others have said, they are not necessary at all.  I have a bosch and I put one in for my parents, both without air gaps, just running the drain high and both have worked just fine.  I know it is not code in Massachusetts or Vermont, and I think all of New England.  If he won't pass you and its code, then you'll need to put it in unless he can allow it.

    1. notrix | Apr 23, 2005 06:15pm | #13

      "Is known to cause cancer to the state of California",That's not fair. Your probably from the upper crust who has had air gaps for years. here in CA not all of us can afford air gaps and recent legistation made it mandatory that all people will have access to air gaps not just the rich. Of course now the illeagal aliens are lining up for their free air gaps and there is a shortage. But we here in CA beleive all peoples should have air gaps wether they pay or not. It's plunged us into heavy debt but the principle of equality of air gaps if worth it!I get so tired of you east coast bougeoise air gap rich CA bashing types with no compassion for the airgapless.If I didn't have to run and get my quiche out of the oven I'd really let you have it!NotrixPS
      That's a tofu quiche..vegan!

      1. DanH | Apr 23, 2005 06:26pm | #14

        Actually, I suspect you have an even larger air gap than most of us ;)

        1. fixit | Apr 23, 2005 06:48pm | #15

          While requirement for air gaps varies by jurisdiction, bear in mind that the air gap is to prevent backwash of waste water into the dishwasher that could contaminating it with nasties like e-coli and salmonella.While you probably will prevent backwash by looping the waste hose higher than the intake that still doesn't leave an air gap that prevents a stopped up drain from backing up into the dishwasher. Also, since most dishwashers are connected to the garbage disposal, and that makes more possibilities for contaminated food waste possibably flowing into the dishwasher, an air gap makes sense.Yes, an air gap is a pain but whether the jurisdiction requires it or not I always think it makes sense.

          1. DanH | Apr 23, 2005 08:29pm | #16

            BTW, I've been told (and seem to recall seeing pictures of) air gaps that were designed to be recessed into a wall or backsplash.Of course, keep in mind that, to be effective, the air gap must be capable of "overflowing", so it needs to be positioned such that a reasonable amount of water coming from it will not cause serious damage.

          2. Jim00 | Apr 23, 2005 11:45pm | #17

            Thanks all of you.  I found the problem, San Mateo county here in California, is still using the 1997 UPC code book wich requires an air gap.  They have not upgraded their codes.  The 2000 UPC, and UBC codes both clearly state that a loop attached to the underside of the counter is just fine.

            I'm not going to drill the counter.  My coustomenr does not want another hole and is going to try to explain to the city it is not required by current codes.

            Thank you all for your responses and humor, I needed some laughs.

          3. Dave45 | Apr 24, 2005 04:08am | #19

            Jim -

            I would suggest that you (or your customer) check with the building department about the air gap "requirement" (or lack thereof) before the sink is installed.  It's a helluva lot easier to drill that hole before the  sink is installed than it will be after it's all finished out. - lol   San Mateo may not automatically follow the UBC and UPC codes.

  5. DanH | Apr 22, 2005 05:23pm | #5

    It's vaguely possible that he'll allow the installation without air gap if you take the loop requirement totally literally and work the top of the loop up into the wall above the sink rim.

  6. hacknhope | Apr 22, 2005 06:18pm | #6

    If you have a faucet with a opening through the counter for a side-sprayer or pump bottle, temporarily remove that and use the opening through the counter as the location for the air gap.  After approval.  Replace the air gap with a loop right up tight under the counter and put the sprayer/bottle back where it was.

    I don't live in California, so this isn't going to give me cancer.

     

    1. glatt | Apr 22, 2005 09:39pm | #7

      Or, you could pull the home owner aside explain the situation and show them how to remove the air gap and put the hand soap container back in after the installation is approved and you leave.  Let the home owner violate the code if they want to.

      1. hacknhope | Apr 22, 2005 10:44pm | #8

         <<Let the home owner violate the code if they want to.>>

        But of course.

        1. HeavyDuty | Apr 23, 2005 03:41am | #9

           <<Let the home owner violate the code if they want to.>>

          But of course.

          And make sure you have no knowledge of it. :)

  7. Brian | Apr 23, 2005 05:10am | #10

    In my county (Washington county Maryland) air gaps were required in 1998, and not required in 2000, so the requirement was dropped. 

  8. Dave45 | Apr 23, 2005 05:03pm | #11

    I'm a licensed GC and engineer in California and have dealt with air gaps for years.  The theory is that an air gap acts as a passive (no moving parts) vacuum breaker to prevent any backflow of contaminated water into the dishwasher.

    99% of the time, neither an air gap or an elevated loop is necessary since the disposal provides an air gap between the dishwasher drain and the sewer.

    If, however, the sewer backs up and the sink (and disposal) is filled with sewage, that air gap will keep the sink from trying to drain back into the dishwasher.

     

    1. hacknhope | Apr 23, 2005 05:59pm | #12

      I once saw a dishwasher full of coffee grounds and 'draino' (I didn't do it) after someone used a plunger on the kitchen sink.   Dishwasher had been repaired and loop not re-established.  An actual air-break connection would likely have averted this.   

      Contractors have to face clients looking at a brand-new expanse of pristine granite and want it uninterrupted, of course.  (As though newspapers, wrappers and sippy cups will never materialize).  So does anyone make fittings that would allow a behind the back-splash air gap, just below the counter air gaps, or other disguising features?  I'm just curious and not for myself. 

       

    2. Jim00 | Apr 23, 2005 11:52pm | #18

      It will however backup on the counter and cabinets and floor.

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