dishwasher: air gap or no air gap

[Erik1776]

Hi all, I am replacing a dishwasher and relocating it on the other side of the sink. I have been told that the current set up does not meet code as the dishwasher drains into the garbage disposal with no air gap. I am also removing the disposal in the new install as it wont fit under the new deeper single bowl sink.
My municipality uses 2021 residential building code but I believe it uses 2014 IL plumbing code. I am getting a bosch dishwasher. I cant figure if I am required to have an air gap or can do without (high loop) or have other alternative option.
Below is the section that I could find on the topic. It says air gap or ABV or DuC. This sounds ultra complicated. Anyone willing to translate?
I already have a faucet, a tap water faucet and a bottle sprayer on the counter, would rather avoid another item clogging the space.

Also I am assuming I can simply use a disdwasher WYE tailpiece to connect the waste pie into the sink drain. is that correct?


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Section 890.770 Dishwashing Machines

a) Domestic Dishwasher (Private Residence). When a domestic dishwashing machine drain line is connected to the house side of a trap from a sink, the drain from the dishwasher shall be carried up to the underside of the spill rim of the sink. Dishwashing machines shall discharge separately into a trap or tail piece of the kitchen sink and shall not connect to the food waste disposal unit.

b) Water Supply Connection. The water supply to commercial dishwashing machines shall be connected through an air gap or by means of proper backflow protection, e.g., a non-pressure type (atmospheric) vacuum breaker or a dual check valve backflow preventer assembly (DuC), depending upon the circumstances.

c) Commercial dishwashing machines shall indirectly discharge to a proper receptor connected to the drainage system or as permitted in Section 890.1010(a).

d) Hot Water. A commercial dishwashing machine or similar dishwashing equipment that relies upon hot water for sanitizing dishes and utensils, rather than chemicals for sanitizing, shall provide rinse water at 180 degrees F., except for a single-tank, stationary-rack, single temperature dishwashing machine which shall provide a rinse water temperature of 165 degrees F., in accordance with Section 750.830(h) of the "Food Service Sanitation Code" (77 Ill. Adm. Code 750).

 

[Reach4]

That sounds like a "branch tailpiece".

 

[Sponsor]

 

[Jeff H Young]

paragraph a says basicaly highloop and not connected to disposal no air gap required as I understand

 

[John Gayewski]

So there's another thread on this very topic. Illinois has an odd rule on this. You can hook the dishwasher to a sink tailpiece, but not a garbage disposal.

If this is a double sink with a garbage disposal you could possibly get a branch tailpiece for the second bowl in the sink. But you start to run out of elevation for drainage pretty quickly with this setup.

Otherwise you need an air gap or a second seperate drain to drain the dishwasher into.

 

[wwhitney]

paragraph a says basicaly highloop and not connected to disposal no air gap required as I understand

And just to amplify the above: the OP suggests that part (b) would apply, but that is only for commercial dishwashers, and it is about the water supply to a commercial dishwasher, not the drain from a commercial dishwasher. For a residential dishwasher, only part (a) applies.

Cheers, Wayne

 

[Erik1776]

HI everyone, I cannot thank you enough for the responses. I have been agonizing about this for weeks and of course, this forum comes to the rescue. In my obsession to get things right, I completely missed the "commercial" in the paragraph I was looking at.
Thank you!

 

[Erik1776]

And just to clarify, this not a double sink. I am just replacing the existing double sink with garbage disposal, with a large deep single bowl with no disposal. The disposal cannot be accomodated with a standard deep bowl and I dont think the half bowl is useful.
So it sounds like this should be easy enough. sink with WYE tailpipe to plug the dishwasher draining pipe into. No air gap. high loop.

 

[Jeff H Young]

And just to clarify, this not a double sink. I am just replacing the existing double sink with garbage disposal, with a large deep single bowl with no disposal. The disposal cannot be accomodated with a standard deep bowl and I dont think the half bowl is useful.
So it sounds like this should be easy enough. sink with WYE tailpipe to plug the dishwasher draining pipe into. No air gap. high loop.

Yes You stated a garbage disposal wasent being installed and it wouldnt matter anyway because your code wouldnt allow it . so you have 2 reasons not to connect to a G.D.
Id just hook it up with a wye branch tail piece and high loop in Illinois