Aav issues

[Kevinjm4]

Installed a new double sink and re did the drains which were previously a trap, no Aav. Double sink previously as well…

everything above the floor is new. Thought I had it figured out but the sinks back up into each other. When I unscrew the aav it drains the water very quickly. AAV is brand new. Possibly I broke it threading it on too snug? But when I take it off I try blowing in and out in it and seems to work fine. I doubt that’s the issue. Studor is “redo vent” product, and supposedly rated for what I have. I do have teflon tape in the threads. Top of studor is just over 6” above top of white horizontal arm. Slope at 1/4” over 12” on white horizontal arm.

Near the floor there is 2pcs 22.5°’s to re-level drain which was out of level coming through floor.

Below sink is a 2” long sweep 90, directly to main vein about 20’ away.

Only other thing to note is that just before that long sweep below the floor there is a 1-1/2” vent pipe that branches off that goes horizontal a few feet then up and out through the roof. I don’t think that is doing anything performance wise, I put it in in ignorance having issues with my drain previously but was told it had no effect on anything. (See photo)

 

[Reach4]

I suspect have a belly in the line somewhere below the floor, and that makes standing water in a drain pipe. But that belly would need to be before your VTR (vent thru roof), and that seems unlikely from your diagram. Are you sure the VTR is good and connected as drawn?

 

[Sponsor]

 

[Kevinjm4]

I suspect have a belly in the line somewhere below the floor, and that makes standing water in a drain pipe. But that belly would need to be before your VTR (vent thru roof), and that seems unlikely from your diagram. Are you sure the VTR is good and connected as drawn?

I suspect have a belly in the line somewhere below the floor, and that makes standing water in a drain pipe. But that belly would need to be before your VTR (vent thru roof), and that seems unlikely from your diagram. Are you sure the VTR is good and connected as drawn?

Another hint: before getting a new sink, my previous double drain sink had a s trap, and no Aav, but same configuration below the floor. It drained fine for a few years but in the last month or two, started behaving as this one is now, backing up… pretty consistently. Perhaps a trip to Home Depot for a 25’ drain auger? Could that help?

 

[Kevinjm4]

I suspect have a belly in the line somewhere below the floor, and that makes standing water in a drain pipe. But that belly would need to be before your VTR (vent thru roof), and that seems unlikely from your diagram. Are you sure the VTR is good and connected as drawn?

Also, I was told that vent through roof isn’t really doing anything, due to its placement… do I not need the Aav in this case or is the thru roof vent indeed useless

 

[Kevinjm4]

I suspect have a belly in the line somewhere below the floor, and that makes standing water in a drain pipe. But that belly would need to be before your VTR (vent thru roof), and that seems unlikely from your diagram. Are you sure the VTR is good and connected as drawn?

Yes vtr is exactly as diagrammed and glued in

 

[Jeff H Young]

plugged drain I think otherv wise why did it drain fine then in last month it stopped working properly on the old build? AAV dosen help with positive pressure but the old vent hacked in should help basically houses built to code work and you dont have to strain the brain trying to compensate for a inferior build but we can only do so much .
draining ok for a few years dosent mean a thing plain as day it was messed up befor you started something is plugged . facts are clear pipes drain