Clogged sink. Tried everything, any ideas?

Hi I just purchased a house and I’m pretty clueless with plumbing.

I have a kitchen sink that backs up when I turned in the garbage disposal it fills with black water and Little Rock like black chunks.

I tried Flow Easy drain opener, then it backed up again after using the disposal then my disposal leaked all over my house. Then I replaced the disposal and snaked the drain and it still backs up.

Only other idea I have is possibly a clogged plumbing vent?

Any ideas?

Cluelessplumber123 said:

I have a kitchen sink that backs up when I turned in the garbage disposal it fills with black water and Little Rock like black chunks.

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Single sink or double?

Assuming this is a single sink, if you put a plunger over the hole, fill the sink with water, and let go, what happens? That is, does it only back up when the disposal runs, or is it any time a lot of water goes through it?

I would expect them to be the same, but you said you replaced the disposal, presumably because of this problem, and it is hard to see how it could be that unit's fault. (Because disposals don't make black water, they just push water around.)

Is there a dishwasher attached to the disposal, especially an unused one? It is possible I suppose that the connection between the two is full of awful rotting stuff somehow misrouted from the disposal, and running the disposal could churn it up.

pasadena_commut said:

Single sink or double?

Assuming this is a single sink, if you put a plunger over the hole, fill the sink with water, and let go, what happens? That is, does it only back up when the disposal runs, or is it any time a lot of water goes through it?

I would expect them to be the same, but you said you replaced the disposal, presumably because of this problem, and it is hard to see how it could be that unit's fault. (Because disposals don't make black water, they just push water around.)

Is there a dishwasher attached to the disposal, especially an unused one? It is possible I suppose that the connection between the two is full of awful rotting stuff somehow misrouted from the disposal, and running the disposal could churn it up.

Click to expand...

Double sink but no dishwasher. The garbage disposal makes the water on that side disappear but it comes up on the other side then when I stop the water levels out on both sides.

Just looked now it’s leaking again somehow with the new disposal on

You already snaked the drain near the sink, open the clean out and snake the line. If you run the disposal with the clean out open (wearing eye protection) you should see when the water backs up. Estimate the flow rate and the pipe diameter and you can estimate how far down the blockage is.

Our kitchen sink has a similar issue from time to time, but it is local, not way down the pipe. The disposal goes to a short straight tube (no more than a foot) which then makes a right angle turn down for another foot or so (all in the wall, so these are estimates) and then empties into the main drain line, thankfully right by the clean out. Those two short pipes tend to accumulate gunk and then it backs up somewhat like yours does. I made a little tool to clean out the vertical part of that pipe. It is just a plastic pipe capped at one end with an adapter to fit on a hose at the other, and with a small hole in the side. When the hose is on water blasts sideways out of the tool, and that can be directed up into the vertical pipe. This is inserted into the clean out while the hose is on (very messy - I always wear eye protection) and it dislodges all sorts of crud which has adhered to the vertical surfaces of that pipe. Between that and running the garbage disposal once it is clear the drain line clears.

That said, the disposal is powerful enough that it seems to bounce water off the right angle turn, sort of blocking itself with the recoiling water. It works best to pulse it than to run it steadily. It does that even when the outlet pipe is completely clear.

The few times that drain line clogged it was because of caked on detergent where the clothes washer drains into it. Going to liquid detergent seems to have eliminated those blockages, at least for the last 10 years or so.