Dishwasher and Garbarge Disposal vent


Old 01-16-03, 12:09 PM
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Question Dishwasher and Garbarge Disposal vent

I had a new Dishwasher installed (this also happened with my old one.) there is a hose which comes from the Dishwasher under the sink to what looks like a vent.The Garbage Disposal has a hose coming from it also and the Dishwasher and Disposal are hooked up together to this vent.Is this the overflow? If so why does water come out of it when i run my Dishwasher.It happens everytime.
Why is this overflow there anyway? Why doesn't it just go into the drain or to the Disposal ?

Old 01-16-03, 12:49 PM
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That is called the air gap. It is there to prevent the reverse flow of dirty water back into the dishwasher, which could potentially mix with the fresh water supply.

The first thing I would check it to see if the airgap is screwed together properly. Take the chrome lid and lift it straight up. This should expose the plastic innards. There is a plastic slip nut that sometimes comes loose on those. Be sure that that is tight.

If that is not the problem, the most likely canidate is that the kitchen sink drain line is running slow. Do you see any water flilling up the sink when the dishwasher discharges? When you run water in the sink for a long period does the garbage disposal and the sink start to back up with water? IF so you will need to snake out the main drain line as it leaves the sink.

If the sink never fills with water then I would check the hose that runs from the airgap to the garbage disposal. It may be full of goo and sludge. Try cleaning it out with a straightened coat hanger, you may have to uncoulple one end of that hose to do this.
Old 01-16-03, 01:47 PM
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I have tried all but the last step and that is probably it or my drain just can't handle the load.
Thanks so much Paulypfunk.
Old 01-16-03, 02:08 PM
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Disconnect the hose from the side of the garbage disposal and make sure the plastic knockout is gone. You should be able to push a coathanger in the pipe stub on the disposal and see it down in the garbage disposal from the sink. If the wire only goes in the length of the pip stub, the knockout is still there. Put a screwdriver in the stub and tap it with a hammer. Fish the knockout out of the disposal, connect the hose.
Old 01-29-03, 01:06 PM
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Is airgap required? Can I install it below the faucet, inside the capbinet? I have no room for a hole in the conuter top?
Old 01-29-03, 02:13 PM
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A dw air gap is code-required in most places.
They are really not necessary on many modern dishwashers anymore, however.
I've had dishwashers here for over 25 years without an air gap, and have never had a problem.
I just have a straight drain hose looped over the top of the dw (and secured there) attached directly to the dw hookup of the sink tailpiece (no disposal, but doesn't matter). Works fine.
(I'm a DIYer, NOT a pro plumber.)
Your call.

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