AAV installed in a basement apartment drain line. If it served only the basement apartment I would think that it would be OK, but it is tied into the soil stack from the bathroom above. Am I correct in thinking this is wrong? 
Bill, is a single AAV serving the entire apartment, or just a single fixture, and where exactly is it installed? Got pic’s?
Ooops - I thought I uploaded the pic. Here it is. This is just for a single fixture in the basement apartment.
![aav and waste stack issue [1024x768].jpg](https://global.discourse-cdn.com/internachi/original/2X/7/72f18bcc99e429a1753be7ce508161c1e5cf1e4a.jpeg)
![AAV issue [1024x768].jpg](https://global.discourse-cdn.com/internachi/original/3X/5/7/5734091e5e9cbc56b40b7bf71b6629090649df45.jpeg)
This is a primary example of why consumers need independent home inspectors.
The IPC permits AAVs while the UPC prohibits them. Why does the UPC prohibit them? Because, the only way that you ever know that they fail is when combustible and/or poisonous gases are released into the home (which can be odorless) and cause an explosion or illness.
The weakness of “code” is demonstrated here which will allow you to take whatever position you want to…but I go with the UPC, even in jurisdictions that enforce the IPC, and describe the safety hazard that it represents.
The whole basement smelled like rotten eggs and not allowed.
Three story building and the plumber said that is a good sign the rest is screwed up not to mention around $3,000 to fix.
James - local “code” allows them ( 1 per building). My concern was with the soil stack it was “Teed” off of. I’m calling it out, but was interested to hear other opinions.
Bill… typically the AAV is located at the fixture being vented, not at the stack… see below…
Excellent info Jeff thanks. The AAV was not far from the sink it was supposed to vent (other side of the wall), but the attachment to the stack was what was bothering me.
In my opinion, the AAV does nothing on the stack unless the stack is restricted above the AAV. Also keep in mind, the typical AAV has a short lifespan of 3-5 years. For this reason, they are required to be installed in accessible locations, and not sealed in walls. (I know this one is not, just adding info).
The guy liked doing all his own repairs, and not very well as you can see.
The plumbing was amusing, the electrical work was downright scary.
Thanks for the replies guys. 