Air Admittance Valve to stop the bad smells

[ShowerSmellProblems]

Hello all,

We just finished renovating our house and there are some issues with the plumbing: that is, our shower has a terrible smell. During the renovation, we had a last minute change to move the toilet down the hall. Although it is a new renovation, we did clean it to make sure there is nothing lodged in the drains etc. From what I read online and watching youtube videos, it seems that the trap is having air intake issues and a potential solution is an air admittance valve.

In my logic, it seems that by extending the stack, the toilet, when it flushes, seeks air and disrupts the shower trap. Even though the smell is coming from the shower, placing a air intake valve at the toilet would make sense. Since our toilet wall is dry wall, it would be easier to pierce into this then the bathroom tiles.

I believe our contractor wet-vented and I drew up the diagram as follows:
View: https://drive.google.com/file/d/1AsMANTjTuIawMo8CxEfAN4Cm5jDeRkuW/view?usp=sharing

• could the Air Intake Valve work in this way?
• would it reduce the smells we are experiecing?
• is it better to put it at the toilet rather than the shower?

Kind regards and much thanks!

 

[oz-plumber]

When you flush the toilet, do you hear any sound from the shower trap?
You should hear something or even see some water movement in the shower trap.

Is the stack vented?

You may be able to fit and AAV on the basin waste downstream of the trap, under the basin.

Not sure why a vent was not installed at the time when the sewer pipe was installed.
What's the length of drain from the stack to the pan?