Oatey39239 8 Stack DFU Capacity Installation Kit with Tubular Adapter Air Admittance Valve, 1.5 in. 20 Branch, White

Awesome product and unlike some others on sale at Amazon, you get everything you need to install them under sinks, including the AAV. We ended up in a new area where we didn't know many people and hired a bad general contractor to build our dream home. He ignored the advice of a good plumber that told him there needed to be a lot more wet vents going through the roof, and hired a plumber who would do what he wanted and only put three wet vents in our house. Some fixture vent pipe had to travel 15 feet to get to a vertical wet vent pipe, where they recommend they travel no more than 5 feet. When our clothes washer or dishwasher expelled their water, it would suck the water out of the both the shower and the bathtub drain and then we would get major sewer smelling coming up through them. We had to duck tape them closed every time we used one of the washers. What no plumber or internet page, I could find, would tell me, was adding these vents to into the same vent system, but not on the fixture who's p-trap was being syphoned or the fixture causing the syphoned (washers) would help keep stop the syphoning. The only easy place to install these was under the sinks and it worked! No more syphoning and sewer smell! Saved $1,000 of dollars not having to pay a plumber and carpenter to install more wet vents.

So, I'll do the same. In terms of quality, this unit is a 5 star. You do get a kit that includes more than what is pictured. It might not be a complete kit depending on your application. For me it wasn't complete because I did need to visit the hardware store for more parts to make it work. Did it work? Yes and no. My application was to prevent stinky drain water from re-entering the washing machine in the basement after draining a full kitchen sink of dirty dish water. It has only happened once since I installed this kit 3 months ago. Before it maybe happened once or twice a week. It also prevented the need to use a plunger on the kitchen sink. Not because of the new valve but because it forced me to take the trap apart and find a butter knife sitting in there. For the folks that it didn't work for - maybe you didn't install it correctly, or you have a pipe somewhere that needs to be unblocked with a heavy duty drain snake or replaced because the blockage is like concrete. Mine is installed correctly but I'm sure that my drain would be problem free if I did any of the other suggestions.

My kitchen sinks drainage have been getting worse for a while with VERY slow draining or a gusher when disposal was turned on (like old faithful but it smells worse). So, I took trap and pipes off and made sure they were not blocked. Then a call to a plumber to snake out the sewer line with a pretty long snake (would make a T shirt: "plumbers have long snakes"). Didn't find a clog. He suggested an air admittance problem with a $1 or 2K fix if his outfit did it. Being a cheapskate, I ordered the Oatey valve and put it in to address that possibility. It tested OK before install, that is, the valve opened and closed very easily/reliably when slight vacuum or pressure was applied. The Oatey valve installed easily, and components were good quality. Unfortunately it didn't solve the problem so no 5th star. And there wasn't an instruction/hookup sheet included and although a simple device there are things to know (need a least a 4 inch distance of valve above the drain line, valve must be carefully placed in a true vertical position) and maybe I needed to know more. I can't fault the product design but the magic didn't work for me.

I am not a plumber and couldn't possibly give you a thorough explanation of how these things function in a house's plumbing system.I do know, though, that when we started getting some foul odors coming from the kitchen sink of our 7 1/2 year old house and those odors couldn't be stopped by any amount of cleaning, I decided to do some investigating under the sink. Before this, I didn't even realize that there was one of these air admittance valves under our sink, but there it was -- and that was the source of the odor.This thing basically is a valve which opens to let air in when water runs down the drain and then closes when the water has stopped. You need it to close because it's on the downstream side of the P-trap, so if the valve wears out after tens of thousands of uses as mine did, you'll get sewer stench flowing back into your house -- yuck!Once I'd pinpointed the source of the problem, it was an easy fix. I just made sure I was buying a replacement valve with the same thread size as the existing one so I could simply unscrew the old one and screw the new one in. Problem solved -- no more stench!!!!I didn't use the supplied PVC pipe because I was simply replacing the valve itself, not doing a new installation.

I used tow of these in our Lake House which was not properly plumbed when it was built (under-stacked). Both of them worked well. Sink traps are no longer siphoning dry and we get much less sewer gas smell emitted at the drains.

This is a nice, all-in-one kit. I thought I would have to install a separate AAV to remote a utility sink away from the plumbing stack in a garage. This kit works perfectly. All the necessary adapters and gaskets are included (you may need a different tail pipe for your sink, which I did.) It's plenty adjustable. Ensure your rough-in drain pipe (1-1/2" DWV) is >7" below the bottom of the sink basin to fit the AAV height which is 4" above the drain pipe. I bought this kit prior to roughing in my drain line so I knew the clearances and could pitch the line properly. The AAV isn't super-high quality (Oatey and Studor offer different styles) but for a single sink, it works well.

I liked the fact that it came it a kit and had all the parts I needed. I am a senior and get kinda' foggy in the brain when I have to figure out all the stuff I need for a project like this. Kitchen sink in 2nd floor apt. was draining real slow even after running a snake down 2 floors and into the main sewer line below the basement floor. This was secondary vent and not the main DWV. It may have had an obstruction from above but I am too old to get on the roof. I thought I would try this before calling a plumber. It did the job and sink is now draining normally. Inexpensive fix that worked for me.

Excelente y fácil instalación. No mas malos olores. Lleva mas de 6 meses instaldo sin problemas