Dishwasher Air Gap

[Joe Funderburk, CMI]

I got a call from Lowes home improvement store tonight. The owner of a house I inspected was there and the Lowes employee called me at the owner's instruction to try to convince me that an air gap isn't required for a dishwasher if the drain line is looped up high. (I wrote up the lack of one in his house.)

Can an air gap be omitted? If not required, how does that square with:

IRC SECTION P2717 / DISHWASHING MACHINES
P2717.1 Protection of water supply. The water supply for
dishwashers shall be protected by an air gap or integral
backflow preventer.

Does everyone cite the lack of a dishwasher air gap? Do you cite it as a significant issue or an "informational" item?

[Michael R. Boyett]

Here is my understanding....the code says, as you state - The water supply for dishwashers shall be protected by an air gap or integral backflow preventer. New dishwashers have an integral backflow preventer for the supply side built into the dishwasher from what I'm told and have read here on the board. The airgap or backflow preventer that we normally see and are more familiar with is on the discharge side not the supply side. I do not write up lack of an air gap on the discharge side if the drain line has been 'high looped' to the tailpiece or the disposer. I believe the home's and city's water supply is protected by that built in device that we don't see. Now if someone can convince me I'm wrong about the built in device then I'll have to re-think my policy.

[Michael R. Boyett]

Also, see this: http://www.home-inspect.com/itatips/04-03.asp

[Brian E. Kelly]

I still see high loops on older homes and leave it at that.

[Dennis Hodkinson]

When we sold our home a year ago, we had just installed a new dishwasher
that had an "integral backflow preventer" for the supply side built into the dishwasher. So, I did not install the visible high loop.
During the process of selling, we painted a couple of rooms and my wife cleaned the paint pan/brush in the kitchen sink.
Even with the "integral backflow preventer" paint got back into the dishwasher. I did install the high loop before we moved.
The good news is that now I have a good first hand story to explain to
buyers and sellers for the need to have a high loop/air gap installed.

[Dennis Hodkinson]

I actually wrote that wrong, I should have said that it had a built in
"high loop" that was installed so that the drain line came out and up
over the top of the unit. It still didn't stop the paint from getting in.

[Blaine Wiley]

In any area that I have worked an air gap is not required if the drain line has a high loop that runs above the flood rim of the sink.

[kweiss]

When I see a high loop rather than a air-gap device, I simply point it out. I state that this method can be effective but may not be as good as the device and is usually accepted. If they wish to pursue it further with city code or a plumber that is their call. As far as the built in devices, I make no comment, that is something that is not visible, so I cannot say whether it is there or not.

[Jeffrey R. Pope]

Originally Posted by jfunderburk

Does everyone cite the lack of a dishwasher air gap? Do you cite it as a significant issue or an "informational" item?

I always write it up as an item that needs correction. The CPC requires an air-gap regardless of any built-in features and the "high-loop" method is not recognized by the CPC.

[twasion]

Originally Posted by bwiley

In any area that I have worked an air gap is not required if the drain line has a high loop that runs above the flood rim of the sink.

This is how I've plumber 'em for ten years. It's okay where I lived under UPC.

[Jeffrey R. Pope]

Originally Posted by twasion

This is how I've plumber 'em for ten years. It's okay where I lived under UPC.

UPC 807.4 No domestic dishwashing machine shall be directly connected to a drainage system or food waste disposer without the use of an approved dishwasher airgap fitting on the discharge side of the dishwashing machine. Listed airgaps shall be installed with the flood level (FL) marking at or above the flood level of the sink or drainboard, whichever is higher.

[Joe Funderburk, CMI]

Originally Posted by jpope

I always write it up as an item that needs correction. The CPC requires an air-gap regardless of any built-in features and the "high-loop" method is not recognized by the CPC.

Jeff, do you mean CPSC (Consumer Products Safety Commission)?

[Joe Funderburk, CMI]

This is a stupid question, but what is the "flood level" of a sink? The rim?

[Brian E. Kelly]

California Plumbing Code=CPC
And yes Joe

[Jeffrey R. Pope]

Thanks Brian.

The CPC and UPC are almost identical, with a "few" exceptions (additions/subtractions/modifications).