Plumb in vent or use air admittance valve?

[jm_middleton07]

Here is my dilemma. My house was plumbed by someone that didn't understand the purpose of venting. I have one 1-1/2" pvc line that runs through the roof. It is only directly attached to the shower drain and goes straight to the main sewer line to the septic tank. I have one bathroom, kitchen sink and the washing machine. I have added air admittance valves to the two sinks. I have a lot of gurgling when the washing machine empties. It does pull the water out of the traps sometimes and we get the sewage smell.
I'm going to cut the wall out behind the washing machine so i can redo the plumbing. Should I use the aav or try to plumb it into the existing vent running out the roof? The aac would save me from getting in the attic to drill holes and run pipe.
None of the fixtures where properly vented. The next thing is the toilet but one disaster at a time. Anyone use the aac on a washing machine? Whats the best route here? Thanks in advance.

 

[Pipe Dreams]

if you can run the vent out from your washing mashine, run it out 2"

 

[Twowaxhack]

Don’t confuse air coming out of the system ( positive pressure ) with water being pulled from the traps (negative pressure)

Atmospheric vents are the best vents

Go outside and remove your cleanout plug near your septic tank, if you have one and then see if your problem changes or goes away completely

 

[jm_middleton07]

Don’t confuse air coming out of the system ( positive pressure ) with water being pulled from the traps (negative pressure)

Atmospheric vents are the best vents

Go outside and remove your cleanout plug near your septic tank, if you have one and then see if your problem changes or goes away completely

At times it pushes water into the vanity sink. It is positive pressure. There is no vent on any of the fixtures until I started adding the air admittance valves. I know it wasn't as bad before and it has gotten worse over the years. I figured it was just because the house was plumbed wrong without the correct venting system. I will look into the cleanout.

 

[Twowaxhack]

The AAV’s you’re using do not correct positive pressure

 

[Pipe Dreams]

The AAV’s you’re using do not correct positive pressure

think the black mobile home type are for positive pressure, and they never seem to fail, funny.