Gurgling Sink Drain

[inmanlb]

Hi,

I have a kitchen sink with two drains that feed into a single pipe followed by a trap before entering the pipe on the back wall. Below this connection is another connection that has a trap and a vertical pipe that goes up several inches and is open on the top. I assume this is a replacement for a vent line since there's no access to the ceiling from this location. There's a third connection on the wall (below the first two) that has a cleanout. The gurgling appears to come from this second trap. I've snaked and cleaned everything I could get to.



I assume that there should be at least an air admittance valve on the top of the vertical 1 1/2" pipe, so I've purchased one of those.

But, the gurgling prevails. Is it possible that the sink should have been plumbed to the middle connection and the vent at the top?

Thanks in advance for your advice.

-Lee

 

[Geofd]

Has the sink always acted like this,or is it a new Condition that white cap is were you can snake from use at least 1/4" by 25' even better 3/8" by 50-75',and go out as far as you can

 

[inmanlb]

I think it's only been happening for a couple years. It does seem to be happening more often the past few months. I question the logic for a trap on the vent line.

I've ran the snake out about 15' but didn't go any further since that made it to a main junction.

 

[MicEd69]

Is it possible that the sink should have been plumbed to the middle connection and the vent at the top?

Yes, the vent should be above the sink connection to the vertical drain.

This is quite an interesting installation. I can't tell from the picture, but it appears that the connection into the vertical drain are not standard fittings. They almost look like they are fabricated out of PVC parts. The drain from the sink probably provides a little bit of water to fill the existing "vent" P-trap to replace any evaporation so sewer gasses won't be coming up through that open pipe.

Anyway, the drain line from the sink should enter the drain line through a Sanitary tee, and the vent line to the AAV needs to be vertical or no more than 45 degrees off vertical all the way to the AAV. Also, the AAV needs to be as high as practical.

To do this right, you will need to open up the wall a bit to confirm (or replace) those fittings, and get the vent properly installed.

 

[Geofd]

If it is a drain issue and it's the main, it doesn't matter if the branches are clean, if the main is partially blocked you have at least remove a clean out or 2 to check flow from the branches and the main, if this is a new condition (2 years) what was it like before that, were the drIans working properly??????

 

[inmanlb]

After running the snake through a couple more cleanouts the issue is gone.

Thanks for all the help!!

-Lee