Dishwasher replacement and air gap

[jap3]

I'm replacing a 20 year old Kitchen Aid dishwasher with a new GE. I thought it would be a simple replacement but the instructions call for an "air-gap". I've searched other posts and I couldn't find anything that looked like what I have.

I read one post that said an air gap MUST go above the counter.

A picture of my setup is attached. Let me explain:

These pictures were taken in the basement. From the bottom, the horizontal pipe goes to a sump. The black hose is the old dishwasher drain. I "think" the closeup is of a vent, then the top horizontal goes to the sink drain.

That black hose went into the bottom of the old dishwasher. There was no high loop or anything.

Will the setup I have now allow me to connect the drain hose to the new dishwasher and feed it to where the black hose is draining now? If not, would raising and securing the drain above the height of the dishwasher give me the air gap?

Thanks for any help offered. I'd really like to do this right myself. If it gets too difficult, I'll just call a plumber.

 

[Gary Swart]

Air gaps are required by many local codes. Those areas that do not require air gaps do require a high loop. This means the drain hose is brought from floor level to under the counter top then down to either the garbage disposer or a special tail piece that is above the sink P trap. Put another way, an airs gaps will always be legal under any code. The high loop is legal only in the areas where local codes do not require them. An air gap is installed through the counter top so that it is actually in sight on top of the counter. All that is involved to install the air gap is drilling a hole in the counter surface and attaching the hoses. The high loop requires a means of fastening the hose loop under the counter surface and drilling a hole for the hose into the cabinet area under the sink. As mentioned, disposers have the means to connect the hose already. Sans a disposer, a simple tailpiece has to be purchased and installed between the sink and P trap. None of these operations are difficult.

 

[Sponsor]

 

[jap3]

Thank you for the reply Gary. I think I would rather use the high loop and install the tailpiece between the sink and P trap if I needed to, but can I use the high loop then through through the floor into the basement where the current waste drain goes for the former dishwasher?

 

[hj]

You do NOT have an air gap. You also have the dishwasher connected directly into the drain system where ANY backup would send water into the dishwasher to contaminate any items in it. Also, most dishwashers will NOT hold water if the drain line goes down like that. In your case, all a "high loop" would do is create a "siphon" which would still pull the water out of the dishwasher. You should completely rethink how to connect the new dishwasher. That AAV is strictly cosmetic where it is installed. It is performing absolutely NO function.

 

[jap3]

hj, I looked up AAV and I know I know what it is. Thank you. I have no plumbing experience, so I only know what I read. I thought it was a vent of some kind but didn't know why the former homeowners installed it in the basement.

I think I'm going with Gary's suggestion: disregard the current drain, install a tailpiece under the sink, above the p trap, and use a high loop. Would that be the best way to go?

 

[Gary Swart]

The "best" way to go is with an air gap. I don't know if New Jersey requires them or not, but an air gap is always approved, high loops often are approved, but not always.

 

[Shacko]

...I think I'm going with Gary's suggestion: disregard the current drain, install a tailpiece under the sink, above the p trap, and use a high loop. Would that be the best way to go?...

Thats the way to go, your original hook-up is totally illegal, that drain line has to go thru a trap before it ties into a sewer line, here's a picture of how it should be done:

 

[Basement_Lurker]

Man that DWV system is horrible.

 

[hj]

The only reason to install it in the basement would be because they had it and did not know anything else to do with it. In that location it is completely useless.

 

[jap3]

I wanted to stop back and thank you all for your help and advice. I had no idea the hookup the previous owners did was illegal.

I ended up using a high loop and draining directly above the trap under the sink using a waste tee. The dishwasher works like a charm. I can't believe how quite it is. The KitchenAid I had must have been at least 20 years old. I got a good 13 years out of it, but comparing it to the new GE is like comparing a drag racer to an electric car in terms of noise.

Thanks again.

 

[Tom Sawyer]

Didn't anybody happen to notice that the AAV is not even a legal AAV ?

 

[Dlarrivee]

In those pictures down below, I see a PVC check valve tying into the stack with a PVC santee... Is the rest of the piping not painted ABS?

 

[jap3]

Is the AAV hurting anything? Should I take it out? I know it's useless where it is, but could it cause problems?

 

[Dlarrivee]

Is the AAV hurting anything? Should I take it out? I know it's useless where it is, but could it cause problems?

There's a rubber diaphragm and a spring inside, eventually the rubber will give out and you'll be leaking methane gas into the home.

 

[jap3]

Good to know. Thank you.