Kitchen sink won't drain without running the disposal

Plumbing Forums

Help Support Plumbing Forums:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

curttard

Member
Joined
Dec 9, 2014
Messages
9
Reaction score
1
Location
,
I've seen this problem posted a lot around the internet but none of the threads ever seem to include the resolution.

We have a single kitchen sink with a garbage disposal. The sink does not drain; if we fill it, it will sit there for days without going down. Turning on the garbage disposal makes it drain immediately. The sink also fills when we run the dishwasher.

The disposal itself doesn't seem to be clogged; if I disconnect the disposal from the trap, water runs through the sink and straight out the disposal with no problem.

If there's a clog somewhere in the pipe, I'm not sure why running the disposal would make it drain, and also I would think it would have become completely stopped up by now -- we've had this problem for a long time now (never got around to taking care of it until now). At any rate, I snaked it 15-20' or so and got nothing.

Is it a venting issue of some sort? What other troubleshooting can I try? If I have to call someone, should I start with a rooter or go straight to a plumber?

Here is a pic of the setup:

sink_zpsca6eeb6a.jpg


Seems weird to me that the pipe into the wall is several inches higher than the pipe out of the disposal, is that a factor?
 
If you want to keep the disposal, you will need to have the drain in the wall lowered. That arrangement is wrong for a couple of reasons. The dishwasher drain hose also needs to be attached to the underside of the countertop to prevent drain water from backflowing into the dishwasher.
 
This same question has been answered in detail on this forum. Simply, you have a clogged drain-snake it. And as phisfood noted, you have to repair the bad drainage piping/tubing under your sink.
 
If you want to keep the disposal, you will need to have the drain in the wall lowered. That arrangement is wrong for a couple of reasons. The dishwasher drain hose also needs to be attached to the underside of the countertop to prevent drain water from backflowing into the dishwasher.

Thanks. Do you mean just clip the hose up there somehow so that it goes up after coming out of the disposal before going back down to the dishwasher?

Do you agree that the problem is most likely a simple clog that needs to be snaked?
 
Thanks. Do you mean just clip the hose up there somehow so that it goes up after coming out of the disposal before going back down to the dishwasher?
Yes.

Do you agree that the problem is most likely a simple clog that needs to be snaked?
That might remedy the drainage problem, but the disposal will fail prematurely, and will likely smell.
 
Thanks. Do you mean just clip the hose up there somehow so that it goes up after coming out of the disposal before going back down to the dishwasher? YES

Do you agree that the problem is most likely a simple clog that needs to be snaked?

YES AND NO

at this moment, it is a simple clog, next week it will be the same thing.

your garbage disposal drain is lowere than the drain coming out ofr the wall

It WILL always clog, because waste drains by gravity. and your gravity is draining TO the sink not away.

2 things you can do, seek a different disposal, with a drain opening higher

or, open the wall and lower the drain

another problem i see, your trap is to deep. it looks to be 6 or 7 inchs water seal
remove trap. replace. with the fittings touching, not that 2 inch gap between them
the deeper the trap seal, the more pressuer the water has got to exzert in moving the water in the trap out. SAVVY?

sink_zpsca6eeb6a.jpg
 
Last edited:
Thanks for all the help.

I forgot to make clear that this has been an issue since we bought the house 13 months ago. There has been zero change since day one; no drainage at all without disposal operating; instant draining when we switch the disposal on.

I did notice the trap being very deep and the drain being too high. I was also annoyed, when initially trying to clean out the trap, to find that it had been glued in place.

So, sounds like I'll be calling a plumber.
 
It dawned on me that there is a window above the sink. So presumably this means the pipe is lateral and not vertical. Removing all the cabinets and opening up an indeterminate amount of wall to lower that is not an option.

So if I fix the trap as Frodo directed and use a straight drain pipe out of the disposal, how much shallower a sink would I need for the system to work? It seems odd the previous homeowners would not have removed the disposal themselves if it never worked right, or that they would have installed it in the first place. The drain in the wall is almost 20" off the floor.

Also, if there is a clog as a result of this configuration, wouldn't the clog be in the trap? It definitely is not. But if there is no clog, even with the height difference between the disposal outlet and the wall drain, I would think the disposal might have water in it but not the sink.

Sorry for all the questions, just trying to find a way to make this situation workable. I think we would rather run the disposal every time we run the sink (as we've been doing for over a year now) than do without a disposal.
 
Last edited:
It may be vertical if there is a studor vent in the wall. I see that alot in the mountains here. Only way to tell is to open up the wall.
 
I guess my final question is, as far as the sink filling up with water unless we run the disposal, is it most likely there's just a clog somewhere past the trap, or that it is an air/venting problem?
 
do away with the disposal, take it out and hook the sink up with out it

scoop the lettuce leaves up with your hand and place in the garbage

or, find a different disposal

or. cut the wall.

its not a venting problem.

a drain works by the water and stuff moving down the pipe at the same time

if your pipe has backfall [thats what its called]

the solid does not get washed away, the water will leave it behind

causing a traffic jam.

compound the backfall with a deep seal trap. you got clogs

1505541_752398664830012_8557767515619736796_n.jpg
 
Last edited:
Back
Top