We noticed a leak under kitchen sink and when I inspected it water was coming out of the vents of the AAV. It's a double sink with no garbage disposal and I think a P trap. I checked the trap and opened the y and ran a snake as far as I could nothing helped so ran to store and got a new AAV put it on and it doesn't leak out the vents anymore but now it backs up in both sinks and doesn't drain. If I unscrew the AAV the water immediately drains... please help thanks!


Since changing out the AAV retried the snake but it will not drain.... I tried plunging the sink and when I would pull up the plunger the water goes down gurgles then comes back up

Replace the old AAV and tell me if it won't drain now. Back to you, Tom

Well like I said I replaced the old AAV with a new one and now it won't drain

You have a restriction, a partial blockage not a complete blockage, in the drain line. With the old AAV, which had failed in the open position, the weight of the water on the partial blockage was enough to push it past the blockage but not quite as fast as the incoming water. Therefore the water backed up and eventually came out the AAV.

With the new AAV the weight of the water is not enough to push it through the blockage and pull the AAV open. With the old AAV the water didn't have to pull the AAV open because it was stuck in the open position. When you remove the AAV the weight of the water is again enough to push through the blockage.

The partial blockage will be some distance away. It would take a lot of vertical pipe to provide the weight to push the water past the blockage almost as fast as you can provide.
Snake the line again and put out a lot more snake.

How far down do you think I should go? I can only get about 8-10 feet from the y which is at the floor... it's a trailer and the sink is only about 11 foot from where the main line goes out but maybe it curves back to the center of the house first... problem is under the house cant see any pipes suppose their in the insulation

A few posts ago I asked, "Replace the old AAV and tell me if it won't drain now." I want to see if the old AAV will drains and the new one doesn't. One thing bothers me. Why is there a AAV installed at all? Back in the 70's I worked as a mobile home construction plumber, On every kitchen sink we ran a vent through the roof. What happened to yours? Let me know, Tom

Logically your kitchen drain should connect to the main drain some where close to the closest toilet.
Put out enough snake to reach from the kitchen to the nearest bathroom.

We just moved into this mobile home about a month ago and there's a lot of jerry riging. I did put the old one back on and it came out the vents again. Sink is under a window so I guess that's why they put in the AAV. I guess my snake ain't doing the job I bought it at Lowe's and I wonder if it's hitting a second bend and not getting around it. As far as nearest toilet it's a straight shot maybe 14 feet on same wall. It's right on the other side of the main line so the main is between them

Are you using a manual snake or a powered snake?
Is there any thing that could be a vent pipe going through the roof in that end of the home?

Sorry for long reply... A manual snake from Lowe's you can crank it to turn it or hook it to a power drill. As far as vent pipes just one for each bathroom looks like where the showers are

I stand by my logic in post 4. You have some kind of blockage. Your snake is not reaching it or it is some kind of soft blockage and the snake is going through it but not clearing it.

If you used the snake manually try putting it in drill. If that doesn't work get a better and longer snake.

Well Landlord finally came over he has a better snake he did manage to get a glob of goop out but still not draining... he tried from under the house somewhere and acid but no effect. I think today he's going to try a hose down the roof vents. Like I said before we just moved in and have had plumbing problems since we moved in. first it was septic backing up into the showers and toilets and now the sink... he thinks that the septic will need reworking and also the yard floods bad and we been having unusally high amounts of rain this summer he thinks that might have something to do with it. I don't know but hew working on it and getting someone to work the septic so hopefully it will get right soon. Anyway thanks to everyone for their input and advice! I guess I can say I tried and I did learn an awful lot from you al about plumbing that may yet help me in the future... thanks again everone!