Dishwasher Air Gap

Old 08-22-12, 05:39 AM
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Question Dishwasher Air Gap

It’s my understanding that a dishwasher air gap is supposed to prevent raw sewage from backing up into dishwasher and if the drain becomes clogged, the air gap is supposed to will discharge the dishwasher water into the sink. Because water has been discharging out of my dishwasher’s air gap, I replaced the air gap yesterday. However, now water is leaking down into cabinet because the sink hole is slightly bigger than the top air gap mounting nut and water is stilling being discharged through the air gap itself. I’m not sure what else I can do because water is flowing to the disposal and through the air gap itself.

Does anyone know why my dishwasher is still discharging water through the air gap?
Old 08-22-12, 06:03 AM
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Sounds like your sink line may be patially clogged. Do you see water come up in the drain?

Its my understanding of the code here in NJ air gaps are not reqired anymore. If removed you need a high loop under the sink. Check your local code. You may be able to remove it.

Says UPC required but that may have changed.

Without air gap.
Old 08-22-12, 12:36 PM
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Makes sense. Thanks lawrosa.
Old 10-19-13, 11:24 PM
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Dishwasher Air Gap Problem

I've had a problem. My sink drain-pipe has clogged resulting in
sink water backing up through the disposer and polluting my dishwasher. It has happened that the dishwasher overflowed onto the floor.

My dishwasher installation instructions includes this under "To drain into a disposer:"

"This dishwasher drain hose is designed to fit most types of food waste disposer. If necessary, adapter kits are available."

(Then this paragraph follows: "DRAIN AIR GAP KIT (Accessory)"

"This accessory protects against a siphoning of water back into the washer tub. It also prevents a back-up of food waste into the dishwasher due to a plugged drain line."

"When the drain hose is connected to an air gap, remove the hose from the side of the tub and route it on a continuous incline from the pump to the air gap. (Coil excess hose and place it in a safe place, perhaps under the dishwasher.")

Can anyone who has used such a kit tell me how they installed it and their experience with it in use? I'm puzzled by the bit re excess hose and storing it.
Are there varieties of air gaps? I have a granite counter-top with no provision for something to be mounted through it.

I read the many confusing comments re air gap and dishwasher. I think my problem should help to clarify the reason for needing one.
Old 10-20-13, 09:13 AM
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Welcome to the forums.

Did you look at the illustrations in post 2 ? Do you see in the illustrations that show a system with no air gap that the dishwasher drain line MUST be run up to just under the countertop ?

If your dishwasher drain line had been fastened all the way up under the counter.... you would not have gotten any water from the sink/drain as the water can't travel uphill.

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