Water from Air Gap

When we run the dishwasher, there is no water escaping from the air gap. If we fill both sides of the double sink, then water escapes the air gap every time the dishwasher drains. The amount of water escaping is not insignificant.

Note 1: the dishwasher drains into the disposal after leaving the air gap.

Note 2: most times when starting the disposal, some water is forced into the other sink then drains.

Things I have done already:
- verified that the drain is clear of obstructions
- verified that the vent to the roof is clear of obstructions
- verified that the disposal drains properly

I am no expert, but my gut tells me the problem is lack of air flow. I assume that would lead me back to the roof.

Any help will be most appreciated.

how far did you snake it???????

Did you loop it high before going into the drain??

did you make sure the plastic knock out is out all the way ????

did you snake from the trap to the main drain?????

although its not very common I have snaked back to back
labs thru a common vent on a roof it worked but that's not the place you start

From the roof, I thought I had cleared it because I was able to run water from a hose without having it back up. I ran the snake out its entire length, which is 15 feet.

If you run the disposal and it comes up some on the other side then you need your kitchen drain snaked. Going down through the vent with 15 feet is not even close to the kitchen drain.

Is it better to get a longer snake and enter from the roof, or use the 15-foot snake under the kitchen sink?

STAY OFF THE ROOF! Why are you on the roof??? Your clog is in your kitchen drain pipe, snake that line...

Will do.

Thanks for all the help!

SHR said:

STAY OFF THE ROOF! Why are you on the roof??? Your clog is in your kitchen drain pipe, snake that line...

Click to expand...

Spoken like someone has once fallen off a roof?

No. I used to regularly climb on roofs for tasks other than plumbing. Not so much anymore because the older I get the more friends and acquaintances I know have fallen off roofs and suffered serious injury and/or disability. No thanks. Not scared of roofs, just always weigh the merits of each potential roof climbing endeavor. In this case I feel OP was putting himself in danger and not even working on the correct drain line...

I’ll never understand why people snake from the roof. In never have, and never will

I ran the snake the full 15 feet down the kitchen drain, and it did not correct the problem (or, it corrected a problem while another remains). I ran water from the faucet, and it drained with no trouble at all. Next, I filled the right sink completely. Once that was accomplished, I pulled the drain plug and kept the water running. Almost immediately, water was gushing from the air gap. I replaced the drain plug, then removed it slowly without the water running. This time, no water escaped from the air gap and all of it drained without issue.

Any ideas?

If there are any more suggestions, I'm all ears.

Add a clean out and camera youre drain line

Have you made sure you’re air gap hoses are clear?

The air gap hoses are indeed clear. I think the next step is to try the camera.

Thanks.

Snake it again with full size blades, (hope you’re not using a Manuel hand snake) and you must go in far enough to reach the stoppage.15 feet doesn’t sound far enough sound far enough

Will do. Thanks again.