Dishwasher Installation

[Milky-G]

I've installed a dishwasher in a new cabinet and countertop section in my kitchen and need help with addressing proper drainage. It's not near the sink. I have the drain loop running up and around the washer, but the existing drop is just above the floor and runs straight down into the basement. This creates a siphoning after the initial wash, so when it refills for the rinse, the water keeps siphoning out. Obviously, I can't install the typical air gap that's used on sinks because I can't risk any backup flooding under the cabinet section. I've heard something about using a "Y" connector type air gap that connects near the floor but runs up the wall and is capped off with, I'm guessing, a filter that only passes air (or maybe it's some kind of one-way valve or ball frit?). Is anyone familiar with setting this up or does anyone have any advice on how to make my current setup work correctly? I've seen dishwashers installed in kitchen islands with no sink, so there must be a common way of connecting this properly.

Thanks.

[trader4]

First, the device you are thinking of, is an air admittance valve. They are one way air valves, that let air in, but not out . They are used in areas where a conventional through the roof vent is not possible, like your island kitchen example. However, they function along with a regular trap and as far as I know, come in sizes made to fit that type of arrangement, ie 1 1/4 up. So, it not clear how you can easily work one into your arrangement.

Second, are you sure that is your problem? What I'm having difficulty with is how a syphon could continue to operate. I would think that as soon as the dishwasher is pumped out and there is no water left, the syphon would break by drawing air into the line from the bottom of the dishwasher. That should happen before it starts to fill again.

[Speedy Jim]

You can use an auto-vent device:

But first.... Is there a P-trap in the basement where you are connecting in to? If not, you have a bad situation. Without a trap, there is always the possibility of sewer gas exiting the dishwasher.

Even if the sink is a long distance away, I would route the drain to the sink trap (inlet) or to the disposal (if present).

Jim

[Pop]

Actually, you should be able to handle that by tapping it into the sink drain, at the P trap, and just be sure one part is hung high enough to be higher than the entry point to the drain. You don't HAVE to run it down thru the floor. Probably a PITA, but run the hose thru the backs of the cabinets, or even into a different P trap if there's one around downstairs; all you need's a place to let some air in. The one way air trap gizmos also work well, but I also discovered they leak after awhile from the crud collection, so you want it where you can get at it easy to check and/or change it out. But, as you found out, you do need something to allow the suction to break. Common problem lost of diy-ers run into the first time. Including me .

[Art]

If this is a Fisher and Penkall drawer dishwasher, it requires special drainage attention. The drainage pipe must be low and have no kinks and only go up to reach the final drain exactly as shown in the installation manual or you will have problems.