Plumbing question

Not car related. Our kitchen sink won't drain. We now have a large single basin with a disposal. If I remove the elbow, there isn't anything holding it up and the drain drains. Use the dishwasher once and the sink fills up and won't drain. Ideas????

Vent issue?

Or clog between elbow and basin

You mean the elbow that connects the dishwasher drain to the disposal?

you've got a clog beyond the elbow.  Get a snake and fish it out? All other drains working well? 

Have you tried peeing in it?

Elbow after the main drain. It isn't a blockage issue. Nothing is blocked. Acing like vacuum, as if it is a vent issue. Should I add a vent? It was working fine until a couple aof days ago.

So the line drains below the elbow, but not above?  Does the sink drain, but not the dishwasher?  Sounds like a blockage in the disposal to me.  

When I get it to floe, it works fine until I run tge dishwasher again. then it just fills tge sink until I loosen up the elbow and let it fill into a pan. It's like once tge flow exceeds capacity it just stops working all together.

I'm not a plumber but that drain set up just doesn't look right.

That according tubing should be replaced. Why do they even sell it?

Raise the "elbow" up higher by shortening the black pipe.

Those are a couple of suggestions.

markwemple said:

When I get it to floe, it works fine until I run tge dishwasher again. then it just fills tge sink until I loosen up the elbow and let it fill into a pan. It's like once tge flow exceeds capacity it just stops working all together.

I still think you've got a blockage past the elbow and further down the line.  Check your cleanout or run a snake.  

I'm with jimbbski-  however it was working, it should be replumbed.  I have plumbed/repaired more than a few, and what I would do is:

Make sure the power to it is off. Remove disposal to where you can pull the rubber and DW drain and clean out any crud. Cut as much as you can, 2-3 inches off the black down drain from the disposal, when you reinstall the disposal crank it 20 degrees or so towards the wall so you can get rid of the accordion thing and replace it with a standard, threaded 1 1/2" ABS ptrap. You may have to cut the pipe from the wall, add a 45, etc.

Yours has too much drop. I like only schedule 40 abs or pvc, not the thin, ACE hardware plastic for sink plumbing. 

Single hole sinks with disposals are tougher than two bowl sinks to drain, as you don't have the other sink to vent the initial push through the trap

Does your DW drain run through an air gap, or is it just  a loop attached high in the cabinet wall? If through an air gap, clean it out.

I don't like the white flex hose, but someone smarter than me put it there.

Disconnect the drain line and run a garden hose down there (down stream) at full power, it will blow the clog out or give you a shower.

Everyone, that isn't my pic. It's similar but not my set up.

I'm not a plumber but check this out.

https://www.wikihow.com/Unclog-a-Garbage-Disposal

Check the corrugated drain hose, and run a snake through the main drain.

It's most likely a blockage. 

Your dishwasher drains much more volume than your sink. The drain is partially clogged- flows fine with sink drain, but is overwhelmed when the dishwasher tries to drain. 

2nd option- the vent. You probably already have a vent. There is either:

- A vent pipe through the roof above the sink (visible from outside). Check for leaves, rodents, etc

- A mechanical vent under the sink (aka: Studivent).  This would be up high under the counter, probably behind the sink bowl. Sometimes these break. If it breaks in the closed position, you'd have no vent. Replace the mechanical vent. 

For everyone else...

Not sure which corrugated line you don't like. The 3/4" corrugated line at the top is the dishwasher drain. It's correct- That's pretty much the only way to do that. 

The 1 1/2" corrugated piece behind the disposal is definitely wonky. 

The electric is also done poorly. 

But that picture is not Mark's. 

mlwebb said:

Single hole sinks with disposals are tougher than two bowl sinks to drain, as you don't have the other sink to vent the initial push through the trap

Had this problem when we bought our house.

Sink worked fine.  Disposal worked fine.  The dishwasher we added would overload the system. The way the house was plumbed, the sink drain and the roof vent came together in the basement ~4' below the sink level.

Since the wife wanted a double bowl sink, I put one in and that solved the dishwasher problem.

914Driver said:

I don't like the white flex hose, but someone smarter than me put it there.

Disconnect the drain line and run a garden hose down there (down stream) at full power, it will blow the clog out or give you a shower.

Even better, use this....

trucke said:

Even better, use this....

These things really, really work. But if you don't get it past the vent wye, it'll fill the vent with water that conveniently comes shooting out at you when you turn off the water pressure.

You have a clog down the line somewhere that isn't a complete blockage.  Run a little water and it doesn't back up because the water is just filling the pipe.  Run the dishwasher and you get a bunch of water all at once.  Fills pipe and begins to back up.  Snake the drain, preferably from a cleanout in the basement.  Then loose that garbage disposal or should I say the anti-christ of plumbing.

In my minimal experience, it seems a lot of kitchen sinks have a mechanical vent like SVreX mentioned.  My ex's kitchen had one (I replaced it with a fully piped vent) and I suspect mine has one since there is no visible vent pipe in the attic above and a couple of years ago the sink started draining slowly until it just - goes. I think my mother's house has one as well.  Common trait with all three houses is the kitchen isn't all that close to the main stack.

Unfortunately, the vents seems to be invariably buried in the wall behind the sink and replacing it damn near requires a kitchen remodel.  Possibly why some townships have ordinances against their use.  That said, running all of the vent piping was a task and a half in the ex's house, so I can understand why builders would want to use them.

How hard should it be to find the vent? So far no luck.

It is a roof vent. Emptied it, snaked it and ran water. Fine. Washed hands with soap and it backed up again. GRRRRR!

Sounds exactly like what mr. Todd was saying, filled the pipe up washing your hands and when you ran water it filled the pipe further and backed up. Lose the disposal, they're worthless