I have an older house (60s) in Canada and the original Plumbing had a garbage disposal in my dual sink. I have since removed the garbage disposal unit and put in a new dual sink but ever since I've done that I've had issues with water backing up from my drain and from my dishwasher. After doing some reading I put in a vent under the sink, this sort of worked but I think it's not high enough because they will drain but sometimes it takes awhile. Also I did not see the main vent header I've seen in other video's, I'm guessing that the garbage disposal unit was the vent therefore with me removing the unit had caused problems. I think I need to cut a hole in the top of the sink and put in an air gap fitting to get proper drainage. Ill post some hand drawn pictures as I am at work and not close to home.

Thanks

An air gap is not a vent
You probably have a partial clog
What happens when you remove the aav you installed does the sink still back up

The garbage disposer was NOT a vent, so removing it had absolutely NO EFFECT on the other sink's drainage. You either have an improper drain configuration under the sink or a partial stoppage.

If I remove the vent I bought the water comes up the pipe.I had a garburator in there for 8 years no problems.
NSFW is the pipe I was using
[www.homehardware.ca]
Here is the vent I put under the sink
[www.homehardware.ca]

Thanks



Edited 1 times.

I had a garburator in there for 8 years no problem I changed the sink got rid of garburator and now I have problems. I used a double P trap instead of single could that cause the problem? Or I noticed that the original pipe is not the 2 inch glue pipe but the pipe you buy in the bag I think it might be 1.5".
Here is the pipe.
[www.homehardware.ca]
Here is the vent I put under the sink
[www.homehardware.ca]

Thanks



Edited 2 times.

double trapping will most definitely cause a problem

when you got rid of the 'garberator' you merely needed to 'tie in' where it used to with NO additional trap feeding into the 'main' trap

==============================================

"Measure Twice & Cut Once" - Retired U.A. Local 1 & 638



Edited 1 times.

to be clear..
two traps draining into a common pipe is not a problem.
one trap drainng into a second trap and then that second trap drain into a drain stack, that is a big problem.
BTW, follow hj's advice.

I will get rid of one of the traps. Not a problem but the reason I thought the garburetor was the vent was because after I remove the garburetor I did what you said and I only had one trap but I still got the water backing up that is why I assumed the garburetor was the vent. The only way I could get this to work properly (sort of)was that other vent AAV I showed you in the picture I had to put up as far as I could underneath my sink for it to work. I just don't think the aav is high enough and that's why it keeps backing up. May also have the AAV installed wrong.

I'm old school I see you used to be with the UA I was also, used to be in Local 488. I find phone calls are better then texting and emails.

Would changing to the 2" pipe help also?



Edited 2 times.

even if it were a venting problem, a picture of the AAV would not help. We need to see HOW you installed it. A larger pipe would also be useless.

I'll be home in 3 days I'll take a picture then thanks for the help.

After talking to a plumber I figured out what the problem was I had to go below my sink to the main drain and snake it out from the drain to the vent in the bathroom. Found two plugs after unblocking all is good.
Thanks for the help of you ever need help with industrial electric or process controls PM me.
Thanks again



Edited 1 times.

NO PM capabilities here on the forum but thanks for the offer



Edited 1 times.