I have had the usual symptomatic water overflow out of the dishwasher air gap on the top of my sink countertop. After replacing the countertop with granite and relocating the air gap hole, I replaced the hose from the air gap to the disposal and insured there was no blockage in the disposal and new hose. Yet I have so much water pressure coming from the dishwasher that it shoots out of the air gap vent. I confirm the water is draining into the disposal from the air gap vent but it seems there is so much water or the pressure is so great the system can't handle the amount of water being discharged and backs up into the air gap. I've even looped the extra amount of hose from the dishwasher to the air gap above the disposal drain height to see if that would solve this. It did seem to take some of the pressure off of the water coming out of the air gap but it still spews out. After searching and reading all the posts regarding this usually common issue, I'm at a loss. Anyone have any ideas?

JLBarny

Is it possible that you also installed a new garbage disposal when you added the granite? If so I suspect you did not knock out the plug in the air gap Garbage disposal line. You just take a long screw driver and insert it into the Garbage disposal air gap return line orifice and hammer out the plug. The plug will end up inside the disposal where you can retrieve and dispose of it.

After that I think your mystery air gap issue will disappear.

Milo Dolezal

Or, you may have a kink in the 7/8" hose (connects air gap and garbage disposer ). Also, remove trim from air gap and make sure the actual tip of air gap is installed properly.

speedball1

Barny, Milo,
Do you guys realize you're responding to the last post of a year old? Barny, how did you get involved in answering a thread thnay was posted over two years ago.? Inquiring minds wanna know! tom

CSI-Stkn

Speedball1 - I actually have this site saved on my lap top to show clients the controversy with air gaps and why I also recommend the loop method- in 20+ years I have never had a complaint with a loop, but with air gaps... at least 40% of installs. I asked a friend who is a mechanical engineer about air gaps and this is his response- poor design! "The air gap was designed in the mid '50's when DW pumps were as efficient as my Dad's Buick Roadmaster. Today's pumps are far more efficient - hence today's DW uses about 30% of the volume of water as a unit 20 years old. Higher efficiency comes with higher pressure and frequently air gaps cannot handle it. Any slight obstruction- food, hair, toothpicks etc. will cause backpressure and viola! out the air gap it goes!" No one ever maintains their air gaps, checking for obstructions etc until water starts pouring into the sink or onto the counter tops. I am sure that over the years you have worked on AG systems only to find food/sludge/gunk built up on the discharge side of the AG and thus causing overflows. Maybe it is time to reinvent/redesign the Air Gap! They look prettier, but they still cause the same problems.

speedball1

Damm! I think I'm in love!! Are ya listening Growler and all you UPC guys that think a counter top air gap out performs a high loop?? CSI! Thank ya-Thank ya-thank ya!!!
Cheeers, Tom

iamgrowler

No one, including myself, has ever claimed a 'counter mounted air-gap out performs a high loop' -- Our argument has always been that it is an issue of code compliance.

We do not get to pick and choose which sections of the code we will be in compliance with, Tom -- It's as simple as that.

MIKIRKER

TSainta, I'm having a similary problem, but can't follow your explaination. I pulled the insert and see the small inlet hose and larger outlet hole across from it. To either side of these two holes are discharge ports. It looks like water would come out of the Dishwasher Pump, spray onto the bottom of the insert, and in threory be redirected to the drain. I believe it just sprays off the bottom of the insert and spreads out; some goes down the drain and some comes out the main overflow to the sink, and some comes out from the bottom of cover. I did not see anything dividing the area. Can you send me a picture or something similar? Also, are the two interior ports supposed to pointed in a particular direction such as towards the Cover vent and ultimately towards the sink?

speedball1

Mikirker,
. In the top of an air gap is an insert with two holes. Inside the air gap are two divisions. One division connects to the inflow side of the air gap (from the dishwasher) and the other connects to the outflow side (to the disposal). If the top insert is put in wrong, water will flow from it when the dishwasher empties. For correct operation of the air gap both holes in the insert need to be positioned over the outflow division of the air gap.


In case you ever want to do away with that pesky counter top air gap and install a high loop Air gap.(see image) I'll be more then happy to help.
Note: In all the hundreds of high loop air gaps that my company's installed we have yet to get our first complaint or service call. This holds true in the high loops that we have advised installing on The Plumbing Page right here.

Growler; Don't be so touchy! I was just having some fun. We are allowed to have fun doing this aren't we?? Cheers, Tom

Attached Images

 

iamgrowler

You might call misrepresenting what I said "fun", but most anybody else would call it 'lying in your teeth'.

speedball1

Then we're in agreement. High loops rule! Say it!!