Slow Drain, Kitchen Remodel - Double Bowl Sink to Single Bowl Sink

[DDahl]

HELP!!!

We're finishing up a year-long remodel of my kitchen. We went from a double bowl sink (garbage disposal on left bowl, with no dishwasher), to a deep single bowl sink (garbage disposal installed, with dishwasher left of sink). In the old kitchen arrangement, there was a bulkhead we wanted removed. In doing that, we had to move a small portion of the vent stack piping. See below:

For 6mo or so, we were working with a temporary double bowl sink. No problems venting, no problems draining. Now, with our single bowl, the water is pooling up and draining VERY slowly. I think it is a venting issue. If you take a small piece of hose and stick it into the drain, it immediately starts to gurgle (like the vacuum has been broken), and begins draining fast without any issue.
We have tried installing an AAV (no change), we even tried changing garbage disposals (no change)… At this point, I am really at a loss.

 

[Geofd]

Have you tried snaking the drain, or tried draining the sink without the aav connected??,also looks like the drain is as the bottom of the disposal but it's hard to tell

 

[JG plumbing]

Where are you sticking this hose? Through the garbage disposal?

 

[DDahl]

@Geofd - Yes I’ve tried snaking; not a clog. Yes, I’ve tried without the AAV connected; no luck.
top of the horizontal is about 1” below the bottom of the disposal outlet into the p-trap.

@JG plumbing - sticking the hose into the drain just a few inches. Doesn’t go through the disposal, doesn’t even go deep enough to touch the blade.

 

[Twowaxhack]

Fill the sink up to the top with the stopper in the drain. Then pull the stopper and see how it drains.

 

[JG plumbing]

It sounds like your moving something in the garbage disposal to me.

 

[DDahl]

@Twowaxhack big 33”x8” deep sink. Filled it up about half way and pulled the plug. Drained how it used to drain before the remodel; fast and normal. Could it be something to do with back pressure or something?

@JG plumbing - not sure if the video really shows it, but sticking the hose in just past the rubber.
View attachment 64558575164__DCF9FF40-8CFF-4CF8-B3FC-D72476C96EC0.MOV

 

[DDahl]

Fill the sink up to the top with the stopper in the drain. Then pull the stopper and see how it drains.

Big 33”x8” deep sink. Filled it up about half way and pulled the plug. Drained how it used to drain before the remodel; fast and normal. Could it be something to do with back pressure or something?

 

[Twowaxhack]

Stand at the sink and take a pic looking down at the drain.

 

[DDahl]

 

[Twowaxhack]

The rubber is impeding the flow. I don’t have a fix for you, sorry.

 

[DDahl]

View attachment 64559085550__B506BFF3-EA5F-4767-BABE-0398994ED346.MOV

 

[DDahl]

The rubber is impeding the flow. I don’t have a fix for you, sorry.

Looks like you were right… what happens if I cut off one of the rubber tabs?

 

[Jeff Handy]

Try cutting off about 3/8 inch from the tip of all the little rubber triangles.

 

[Twowaxhack]

Looks like you were right… what happens if I cut off one of the rubber tabs?

Personally I wouldn’t do that. I suggest calling the manufacturer and see what they say. I’ve seen this before but never investigated a fix, I think ultimately it’s poor design.

I’ve read that some people cut a little off each rubber tab. I’m not telling you to do that.....

 

[Twowaxhack]

Remove that AAV, it’s not doing anything and will eventually fail.

 

[Jeff Handy]

Disposal drain pic, lightened up.

 

[Jeff Handy]

https://everydayoldhouse.com/garbage-disposal-splash-guard-slow-to-drain/

 

[sarg]

Clearly unstable.

 

[JG plumbing]

Sorry I ruined it for you sarg.