Dishwasher Air Gap - Neccessary?

[glorystomper]

Ok, I know that some areas require the air gap and some allow you to loop the hose as high as possible before connecting to the disposal. But forgetting about code requirements for a minute, is it really necessary to install an air gap? My previous dishwasher did not have one and my new one is a high-quality Miele Optima and I don't see anything in the installation guide requiring the air gap. I'd love to avoid the unsightly air gap on the counter-top, but don't want to risk damage to my new kitchen. So do I really need it?

[Pulpo]

Call the manufacturer to be sure.

[Furd]

The air gap is for health reasons as it absolutely precludes dirty sewer water from siphoning back into the dishwasher. Any other method can under adverse conditions cause such a back siphonage and contaminate the dishwasher.

Some areas will allow a connection like this. where the dishwasher drain is the copper piping on the right and it goes into a special fitting that is vented outside through the wall. Your local plumbing inspection office is the place to ask for more information.

[zoesdad]

furd I try to learn everything I can on the forum. What is the gray primer paint on the wood for?

[Furd]

What you think is paint are in reality steel "nail plates" to prevent the drywall screws or nails from puncturing the pipes. Same idea as when running electrical wiring less than 1-1/4 inches back from the stud face.

[zoesdad]

gotcha furd! thanks. Had heard of the plates for electric wires but had never seen them. Didn't think about pipes. Sure can see you'd want them there.

[DUNBAR PLUMBER]

Ok, I know that some areas require the air gap and some allow you to loop the hose as high as possible before connecting to the disposal. But forgetting about code requirements for a minute, is it really necessary to install an air gap? My previous dishwasher did not have one and my new one is a high-quality Miele Optima and I don't see anything in the installation guide requiring the air gap. I'd love to avoid the unsightly air gap on the counter-top, but don't want to risk damage to my new kitchen. So do I really need it?

California requires an Air Gap.

Necessity is based on the 1000's of incidents whereby people became sick or ill, some rare cases led to death where the direct connection from dishwasher to sink was found with a high loop scenario, providing no safety measure in regards to protection.

[594tough]

The air gap is mandatory under the California Plumbing Code, and most inspectors in my experience don't give a bleep about your new granite island...!

CA 2007 Plumbing code 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 air fitting.........

By the way, "domestic" means residential. They don't give a bleep what the instructions for your Miele or Bosch may say!

[steve_gro]

FWIW, there are all sorts of different trims available for air gaps - chrome is not the only choice. And there are combo air gaps that combine a soap dispenser + air gap.

Scott Duncan's Plumbing Inventions: Air Gap / Soap Dispenser Combo