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Garbage Disposal Backing up into Your Other Sink? Here’s the Fix!

There’s nothing more annoying than having your garbage disposal back up into the other sink. Not only does this stink and spread germs, but it’s quite a hassle as well. Calling a professional to fix your sink can cost a lot of money. Before you do this, utilize the tips below and see if you can work out the problem yourself. In the end, you just might save yourself some cash.

There are several possible reasons why your garbage disposal is backing up into your sink. Some of these reasons can include overuse, a clog in the drain lines, or even installation problems. Whatever the reason, if you follow the steps listed below, you’ll get your garbage disposal working in no time.

When your garbage disposal is backing up into the other sink, try and plunge it clear

Fixing a clogged pipe is a fairly easy job that can usually be done without calling a professional. First, you will need a sink plunger and a garbage disposal plug. Once you have them, you can begin. Follow these easy steps below:

  1. In the other sink, the one opposite to the garbage disposal, start by filling it with water. You’ll want to add 3 to 4 inches of water. Make sure you don’t add more than that. If you do, use a cup to take some out and pour it into the bucket.
  2. Next, you’ll want to plug the sink, the side with the garbage disposal. Take your sink plunger, place it over the opposite drain, and start to work the plunger up and down. If you don’t feel the suction, then you’re doing it wrong. If that’s the case, simply center the plunger and plunge again. It’s also important to note that you’ll want to make sure you’re using a sink plunger and not a toilet plunger. These are two different tools with two different shapes.
  3. After you have worked the plunger several times, remove the plug in the sink with the garbage disposal, turn on the faucet, and let cold water run down the drain, then repeat plunging on the side with the garbage disposal.
  4. If the clog still hasn’t cleared, you’ll want to repeat the process. This time, work the plunger a little longer, and again, unplug the drain and turn on the faucet back on. If the clog still hasn’t been removed, the clog is probably much further down the pipe than you imagined. Once the clog is down that far, plunging just isn’t effective.

Use a plumber’s snake to try and clear the clog

Before you start, you’ll want to gather the following tools: an adjustable wrench, pliers, plumber’s snake, and a bucket.  Also, you’ll now want to take out everything from under the sink and place your bucket directly under the sink pipe. Follow the steps below:

  1. Locate the threaded plug on the trap. You’ll need your pliers to do this. You can also use your adjustable wrench. Loosen this plug and remove it, but make sure you don’t lose it. Put it in a special spot. (If it doesn’t have a threaded plug, remove the whole trap.)
  2. Once you have removed this plug, carefully take off the elbow-shaped pipe. If you’re unsure which pipe this is, it’s the one that connects the garbage disposal to the drain. If you realize that this pipe is not where the clog is, re-attach it.
  3. Next, locate the tailpiece and take it off. The tailpiece is the component that is hooked to the sink drain. You’ll also want to fully clean the tailpiece before you re-attach it.
  4. If the tailpiece is not the issue, you’ll want to go ahead and remove the trap. The trap is connected to the main drain pipe.
  5. You’ll now want to get your plumber’s snake and begin working it into the main drainpipe. It’s important to note that this is the pipe that’s connected to the back wall.
  6. When you’re pushing the snake down the drainpipe, you’ll want to crank the handle of the device and make sure you turn it clockwise. You should start to feel some resistance.
  7. Keep cranking the handle until you remove the clog. One the clog has been removed, clean your snake off with water or a towel.
  8. Put everything back together, including the trap, the plug, the elbow, and the tailpiece. You’ll also want to make sure the threaded plug is tight.
  9. Finally, turn on the faucet and run hot water down both drains. This will clean them both and remove any debris still left in there.

Both your drains should be working fairly well now. It’s also important to note that you never stick your fingers in the garbage disposal to try and remove the blockage. This could lead to a serious tragedy.

If you’re still having problems, it’s probably best to call a professional. More than likely, the clog is further down the drain and you will need special tools to get the clog removed. On the other hand, you might also have some installation issues. For more information on this, read the Installation Problems section below.

Installation problems

Installation problems could also be the reason why your garbage disposal is backing up into your other sink. The garbage disposal and the sink basin each will have its own separate trap. Usually, both of these traps are both connected to the main drain line that goes into the wall. Together, they are Y-shaped.

Now, with some systems, the garbage disposal is connected to the tailpiece of the other sink. With this system, the pipes make a T-shape. The problem with this setup is that sometimes the water can be pushed up into the sink opposite the garbage disposal, causing a clog.

You can, however, buy a specialized T-piece made to direct the flowing water downward. If you’re experiencing clogs on a regular basis, it’s best to install a Y-shaped system instead.

Avoiding blockages

The best way to prevent your garbage disposal from backing up into the other sink is to take preventable measures, which will not only save you time and money, but they’ll also help keep your garbage disposal and drain in good working condition. So, what are these preventable measures?
First, be careful what you put down your drain to grind. Some scraps can clog your drain and freeze the blades of your garbage disposal. Things you should not grind up include coffee grounds, rice, pasta, potato skins, apple peels, orange peels, bones, and eggshells.

In addition to this, never pour grease down your drain. The grease can begin to clump up and form blockages or even jam the blades of the garbage disposal.

Another tip for keeping your garbage disposal from backing up into the other sink is regular cleaning. By pouring a little dish soap down the drain and running cold water from the faucet for about 15 minutes from time to time, you can keep the gears and the blades of your garbage disposal working well.

By doing this, you help prevent build-up corrosion, rust, and grime. Even if you don’t use your garbage disposal very often, you’ll still want to run cold water down the drain while running your unit from time to time.

 To keep your pipes clean, pour a cup of baking soda and a cup of vinegar down the drain. Start with the baking soda, and then pour the vinegar after it. This little trick will help you keep them clean. Grease and other particles can clog up pipes over time, but by doing this from time to time, you can really save yourself a lot of trouble in the future.

To keep your blades sharp, take a few ice cubes and grind them up. You’ll want to do this every now and then. How does this help? Grinding ice cubes will help sharpen the blades of your garbage disposal and keep them cutting well. If your blades are dull, the motor will have to work harder to grind up the scraps and will ultimately have a shorter life span.

Another reason why it’s good to grind ice cubes is that doing this can also help breakdown the grease build-up in hard-to-reach areas. Over time, grease can start to build up and lead to problems. This is why keeping your garbage disposal clean is important.

The last tip for avoiding blockages is never throw trash into the garbage disposal. This includes hair, cigarette butts, twist ties, plant clippings, utensils, pull tags, and rubber bands. Even if you think it’s not a big deal, just don’t do it. It’s easier to throw the item in your garbage can.

Purchasing a new garbage disposal

If, by chance, you do have to purchase a new garbage disposal, choose one with an auto-reverse mode. This feature is really worth the extra money and will help prevent your garbage disposal from becoming jammed and clogging up your pipes. You should also invest in a unit with at least a 1 horsepower motor. A stronger motor means your waste will get ground up into smaller pieces, and you’ll have to deal with fewer backups.

Kevin L. Sharp


Tuesday 7th of November 2023

Thank you so much! It was very kind of you to take the time to give me just the information I needed to fix my backed up sink, quickly. The bonus for me was your comment about a sink specific plunger. I recently purchased a weird looking plunger for my bathroom. Now I know why it is such a weird shape. It fit the sink drain perfectly and worked like a charm! The t-pipe from the disposal turned out to be where the clog was and now it's gone. I am thrilled!