Inspector says I need a "high drain loop" or "air gap" on my dishwasher... I have a question

Question

I have granite counters, and I've yet to see those little stainless steel drain pipe pop-up things in granite, so i didn't get an air gap installed. Instead, the installers of the dishwasher put the drain hose up very high and connected it to the bottom of the counter. Doesn't this constitute a "high drain loop"?

Answer 1

the reason for this code is if you sink drain ever stopped up, it would not drain into dishwasher, the dishwasher drain hose needs to be above the highest part of sink " flood level rim". An air gap fitting is a device that you would mount in one of the holes in sink. With the vast number of differently configured kitchen faucets nowadays, a 4 holed sink w/1 hole being used for air gap fitting, you can get a decent faucet w/spray that will fit in other 3 holes. there are also faucets that use only 1 hole, so depending on how many holes in granite you have ( or sink) you should be able to make something work.

Answer 2

Put the Air Gap in.

Dishwashers will syphon dirty water from a sink if it does not have an air gap in the drain hose.

It does not matter how high the loop is, if there is water in the hose, it can syphon from the sink.

All that is neccessary for a syphoning action to start is the hose is filled with water. The dishwasher uses a pump to fill the hose to drain the dishwasher, or maybe someone forgot to grind the food in the garbage disposal, clogging the drain.

Most dishwasher's have an anti-backflow valve to prevent this, but they don't work very well. Once the seal on the valve is worn a bit, water can slowly syphon from the sink.

The first few times it will probably just like dirty standing water in the bottom of the dishwasher, and you think maybe it is just clogged from food particles or something keeping it from draining.

When it gets worse, the dirty water from the sink fills the dishwasher, and overflows onto the floor.

It syphons slowly. You might start the dishwasher, and watch it finish, everything looks okay, you go to bed, but in the morning, dirty water everywhere.

Put the Air Gap in.

They are not metal, but cheap plastic. Make sure you have the correct hose sizes. It is easy to break or strip one when installing.

A high drain loop is just a loop in the drain hose up high, yes it is a cheap fix, but it will rarely prevent syphoning. It may be "Acceptable" to code, but it is not a real solution. All that is necessary for the sink to start a syphon is for the water level in the sink to be higher than the "loop" in the hose

If the dishwasher pump fills the hose with water, it is not necessary for the water level in the sink to be higher than the high drain loop, it only has to be higher than the water level in the dishwasher to start flowing. And the water level in the dishwasher is only a few inches from the floor.

Yes, air gaps may get clogged. Anything can get clogged enventually.

You may not have to drink another hole. Some kithen faucets do not have valves on each side, and come with a special cover plate to allow you to open up the other 2 side holes for other purposes. I put a purified water tap from a RO filter on one side and the air gap on the other.

I did have to drill the hole once, it was more fret than difficulty, but I have never drilled through granite. Get a bonded pro to do it if you have to drill.

Answer 3

been doing it like this for the past 31 yrs........

lic. gen. contractor

Answer 4

Yes, what you have is a high drain loop. A few years ago Air Gaps were a big thing and many Plumbing Codes required them. After a while, they found that they didn't work that well and often clogged up. This Code was changed back to Drain Loops in many areas. I have done work in Ohio, Florida and Arkansas and never installed an Air Gap.

Answer 5

Yes, it serves as an air gap. I have the same thing at my house and I've done installations that way. The inspector is just going by the book. He wants to see something manufactured, I suppose.

Answer 6

It should be in a loop, with the top of the loop above the ends of the hose.  The top of the loop needs to be higher than the point where the hose connects to the sink drain.  The idea here is to prevent waste water from flowing back into the dishwasher.

Answer 7

Was that a city or county government inspector?

Because high drain loops was outlawed about 24 years ago under UPC and IPC codes.

As sorry as air gaps are, they are what is legal.

Answer 8

I think it would be considered a high drain loop.