Slow draining sink (a.k.a - Pulling my hair out in Omaha)

[blues327]

I'm really hoping someone can help me, because I am on day 3 of this issue.

A couple of years ago, my wife and I decided to remodel our basement bathroom from an old 3-sided shower to a corner glass shower, with a new toilet and vanity. What we found when we tore into it, was several hidden electrical boxes behind finished drywall and a plumbing configuration that looked like the old pipe screensaver from Windows. Well, 2 years later the bathroom is complete except for one issue, the non-overflow sink we installed takes about 30 minutes to drain. We have an umbrella drain w/o overflow installed. Because it is a floating vanity, there isn't a lot of real estate to work with underneath the sink. I have attached some pictures. From the sink drain trap the drain takes a 90 degree drop about 6 inches from a T down then travels 30 inches to the corner where there is another 90 degree turn and travels about 18 inches to the main stack/vent. I tried to install an AAV under the sink, but I could only install it about 3 inches above the trap and the instructions said it should be at least 6 inches above. So after much deliberation I opened up the back of the wall, which is in the laundry room. and installed an AAV 2 feet above the T joint. The odd thing was that while it didn't work at first, after I fill the sink with water, when I loosened the AAV a couple of turns the sink emptied very quickly. But only the one time. I have tried it without the AAV (just opened the pipe on the top) with no luck. Any help would be greatly appreciated.

I'm going to go work on my stairs now.

 

[Reach4]

I am not a plumber. That elbow at the bottom of this picture https://terrylove.com/forums/index.php?attachments/1129151028-jpg.31917/ should be a long sweep, and there is a really good chance that is where the clog is.

Maybe there is a way to make this right, but I don't know if there is enough space between the sanitary tee and properly turn to horizontal.

I would remove that AAV temporarily for access. I would shove a small Brasscraft drain bladder, on a hose, down from above past the san tee and try to blow the clog out. Expect a re-clog if you don't put a sweeping fitting as you transition from vertical to horizontal. If you are careful what you put down the drain, it might be a long time before a re-clog, even with that bad elbow.

 

[Sponsor]

 

[Standardairconditioner]

Drains like horizontal and down only, no up. You might be trapping some air pockets there, which is what we only want to happen in a p-trap, and no where else along the drain.

You may try your best working on the clog problem without tearing open any more drywall, but I'm pretty sure this needs to be redone right so the drain path only has horizontal and down.

 

[blues327]

Thanks for the info.

Reach4, after going through some old pictures we had during the reno, it looks like they had clogs down there before because there was a cleanout under the sink. I have a small pump that I tried to insert down the drain from the AAV port. It worked minimally.

StanardAC, going off of your pictures my configuration is Figure 3. I don't think there would be any air pockets, but I'll take a second look.

 

[hj]

You are "airbound" somewhere and somehow. When you loosen or remove the AAV that allows the air to escape so the sink can drain. Normally, it happens because air is trapped between the water in the sink and the water in the trap, but if that were YOUR problem removing the AAV would not make any difference, assuming you have the AAV installed properly. Figures 1,2, and 3 would ALL drain properly and would not cause your symptoms.

 

[Smooky]

You may be able to slightly unscrew the “umbrella” to increase the opening so it does not trap as much air. You can put a little spacer of some sort in the socket to tighten it back up. Sometimes there is a rubber seal on the bottom of the umbrella that can be removed that may also allow more air to escape.