Hi

Just moved to a new place, and lovin' it -- except for the kitchen sink.
It drains very slow, and backs up into both bowls.

I dismantled the whole construction, but no clogging in the PVC-pipes.
There was a Studor Redi-Vent installed, see STUDOR (R) inVENTive Technology (TM) - Air Admittance Valves. Without the Redi-vent, water drains fine and fast, but I can't quite have the water running.

Tought it might be the Studor, and got a Oatey Inline Vent (like this In Line Vent :: Oatey.com, just not in Chrome. $3 at HomeDepot). The Oatey does not improve things.

Any ideas? Your help is much appreciated!
Regards, Rudi

Hey ruditeesen... Does not sound like a vent issue at this time. I would suggest that you try this:

Plug up one side of sink with a rag... fill both sinks with water to about 3 inches... then have friend hold down rag while you plunge that drain... Here, the push will be more important than the pull ('cause of vent).

Try this for a minute or so.. see if that improves things. If not then time to clear that drain with a power snake.

Let us know how it goes. If my answer helped please RATE THIS ANSWER by clicking on rate this answer button. Thank you.

Let me understand this, when you remove the AAV everything is OK, right? You replaced the AAV with an Oatey and the problem persisted but if you pull the Oatey it drains fine, right?

Hey Ballenger... he said : "without vent water drains fine and fast, but I can't quite keep the water running". Why I went for the plunge or snake idea.

Yep, I was bit confuesd by " but I can't quite have the water running." Maybe he can explain further

Thanks for the quick answer.

To be more precise:
It's a double sink with a p trap and an inline vent about 6" above the trap. Then the pipe goes into the floor.

What I meant:
If the water runs at slow volume, it drains "ok" -- with or without vent. It backs up at higher volume, and if I had taken the vent off, the water is pushed into the cabinet.

Maybe the floor pipe is clogged?

Rudi

YUP... drain is clogged. TRY my plunger trick.. then get back to us.

Sorry but I got to ask another question. 1st you have the sink drains, 2nd they come together and then enter a single trap. 3rd the single trap then has an AAV mounted horizontally 4th the drain leaves the AAV does a 90 and goes straight down into the floor. Do I have your piping described correctly?

Sorry about that. Once again. Please see below.

Hey again... DID YOU TRY THE PLUNGER TRICK?

If you did and it did not work then I would remove that vent and snake the drain line... replace vent and test. Period. It is what I would do.

I'll try the plunger trick -- but need to buy one first, my wife won't let me use the bathroom one ;)... I'll post if it worked, by tonight.

You could also try temporarily capping the vent with a wet towel and then plunging. The AAV as installed makes regullar plunging out of the question since it vents the air rather than allowing the sucking action of plunging..

Hi again.
Tried the plunger trick, and it definitely improved matters. I capped the AAV-pipe and the 2nd sink with the towel, and plunged the other.

Water drains faster, but still not perfect.

STRANGE: After letting the pipes run full with the AAV-pipe stuffed with a towel and plunging, the water drained very well -- so well, in fact, that I could not repeat (filling pipes, stuffing, plunging). However, as soon as the AAV was put back on -- and I tried either the Oatey or the supposedly better Redi-vent -- it drained again slower.

Hmmm... well that is not totally out of ordinary... when vent not in... more air enters drain... so flows better. The AAV can only let in so much air to system and still keep sewer gasses from entering your home... so not a surprise.

Tell me... if you put the cap/plug back in and remove the vent.. how does it drain then? Then take advantage of totally plugged drain.. have a friend hold that rag in other sink... and fill sink and plunge again... let me know what you find.

If that does not do it... will probably need to snake the drain... but try all this and get back to me.

If my answers help, please RATE THIS ANSWER by clicking on rate this answer button at upper right or at bottom of this post! Thank you.

OK now is the time to fill both sinks with the hotest water available and maybe an extra bucket or two of hot water. Pull both sink stops at the same time and allow to drain. If this doesn't cure you ills its time to rod. You may have trouble with a 1/2" rod but I'd try that first, you could drop down to a 1/4" rod if you have to.

It's worth than ever now. Strange. It does in fact drain slower than ever.

What do you mean by "rod" -- snake the floor pipe?

I'll still try the baking soda/vinegar/salt-hot water trick.

"baking soda/vinegar/salt-hot water trick" No, skip the water until the mix soaks over night. 1/2 cup table salt mixed with 1/2 cup baking soda then dump down the drain. Tomorrow flush with a bucket of hot water. Rod/snake are the same thing, remove as much of the black piping as you can and then rod down through the floor. Make sure the pipes you remove are also clear, probably will be.

Hi Rudi... Hey... like Ballenger said... try the stuff he mentioned overnight... then here is what I would do.

Then, if not improved enough to make you happy... remove the pipes that you can by hand. Then go to store and rent a small electric snake... 3/8" cable size should be good...and machine should come with a set of leather gloves. While you are there, purchase an 1.5" ABS dandy clean out fitting (also called a test tee.. see pic. Below) and the proper cement/primer (read cans) and some teflon tape.

Now, go home and with a hacksaw or a sawzall cut out enough of the horizontal pipe to cement in the dandy clean out fitting (Please hold against yourself when cutting the pipe so do not break below the floor) Then, before cementing the cleanout on...snake that drain.

You could go down the vent fitting but will be much harder than if you just cut in a nice cleanout close up near the front... and that cleanout will be readily accessible for the future as well.

So then you snake the drain... go 25 feet or so... working back and forth/ back and forth... then cement dandy cleanout on, install remaining fittings, teflon the dandy cleanout plug and install that and then test your drain line.

Test by filling the sinks and draining... that should do it... if it does not undo dandy cleanout plug and go for it again... this time with a trickle of hot water as you go... try to churn/clear the pipes that way. Once you see her starting to clear, increase the water flow which will wash your snake and increase the washing/clearing of the drain line while working with the snake.

LET us know how it goes!!

Just for the record here -- and I will make that clear in a rating later -- without your guidance I'd have had to call (possibly expensive) help already. Really appreciate it. I think as well that we're getting close to the problem.

See the pics below, all taken in the laundry basement below our kitchen --

Pic (1) On the right the vertical black PVC is the double kitchen sink floor pipe. On the left you can make out an older vertical metal pipe, which comes down from the bathroom NEXT TO THE KITCHEN. It looks as if they put the kitchen in at some point -- this is an old villa, split into 4 apartments -- and messed up the fix. Problem is that the PVC pipe that connects the kitchen to the bathroom and rest-of-the-house sewer drainage SLOPES DOWN TO THE RIGHT.

The bathroom sink drains perfect. All this points towards the clog being right in the L-turn from the vertical kitchen floor pipe, or?

Pic (2) is the "dirty fix", where they linked the kitchen drain to the older existing system.

Pic (3) is the left upward turn that kitchen water has to make, upwards.

Pic (4) is the head of that piece -- leading to my question: Can I just take that off, with a bucket underneath, scrub it out, and -- at least for now -- avoid re-doing the whole thing?

Rudi

YUP... you sure can. Take a bucket, like you said and take that end clean out plug out. Most likely the problem is between the plug at end and the clamp on left (joining old pipe).

You will need a stick... swirl around... may even want to let some water drain out while holding bucket underneath and let the water backwash the pipe a bit.

Further, you can undo that clamp as well... slide clamp back, peel back one side of clamp and gently push whole pipe over just enough to get flashlight and see if there is also a problem there.

Otherwise, once you get plug off end...and use stick to get majority of gunk out...hook up a hose to hot water and wash the inside of the pipe down (you will get backwash here..so be prepared with bucket underneath). Slide hose in if you dare...cover pipe end with rag over hose..have someone turn on in spurts...that will wash down nicely.

AND as you said... you will need to fix that back pitch someday. I would just cut right above the fitting with the cleanout... cut out 2 inches or so and just clamp (Like other clamp) or cement on new ABS coupling... would not take very long... just be sure if doing form underneath that you check to not loosen anything upstairs.

Hey, just as you've been doing... keep us posted... on the downhill side now!