Garbage Disposal Backing Up Into Side Sink | How to Fix it?

I notice the water backs up every time I run the garbage disposal for a few days. The hidden reasons halt me from taking the right action to rectify the problem. But my curiosity kept me going, and I self-helped through one of the videos on YouTube. Do you interested in how I solve the Garbage Disposal Backing Up Into the Side Sink issue?

Garbage disposal problems are related to ultimate clogging. It can be anywhere at any time. You can estimate why garbage disposal backs up into the side sink due to clogging in the sink drain, installation problems in drains, or unhealthy hygiene practices of not washing away food remaining’s after food grinding.

The article covers famous sites of garbage disposal where the chances of clogging are imminent. In addition, you will learn the practiced tactics to clear the drain using a sink plunger garbage disposal and plunger snake.

Why is my Garbage Disposal Backing Up into the Other Sink?

Think of how your minor mistake can affect your garbage disposal and how far. The chances of garbage disposal backing up into another sink only decreased when peeping deeply into the behind story.


Clogging is not the first step that leads to a damaged disposal unit. Instead, it will contribute to how you use it and with what waste items. There are two main reasons for garbage disposal clogged.

One is the remaining food in the linings of the disposal waiting to be washed away, while the other is stuffing the disposal with such waste, such as larger chunks of food waste, cutlery, or tangible objects that left no way other than to block the drains.

When both reasons are combined, they slow the water flow across the pipelines. Hence, causing the back-up into the other sink without facing any resistance. Also, you will notice a foul smell as a by-product of your blunder.

Garbage Disposal Backing Up Into Side Sink Clogging

Garbage Disposal Installation Mistake

Make a note in your mind that your garbage disposal is not alone in cutting food to liquid waste. Instead, it combines with drains of different categories to do the purpose. Any mistake during garbage disposal installation costs you to reassemble it and find where the culprit lies.

Water flow follows the principle of gravity and easily gets through the drains if you pay attention to fixing the pipes slightly below the height of the garbage disposal outlet. This way, the natural flow of running water and waste going down the drains is not disturbed. Additionally, you will notice the chances of clogging diminish as the lower-installed pipes lose the capacity to hold water and food waste.

Garbage Disposal Installation Mistake

How Do You Fix a Garbage Disposal Backing Up into the Sink?

Maintaining the normal flow of running water down the drains is relatively easy. All you have to do is to combine your hands and head and use some equipment to unclog the drains in different parts of the unit.

Tidbits: you must recognize the exact location of the backing water. Assume the drains are at fault if it stands in the other sink. Otherwise, unclog the garbage disposal if you see water returning into the sink attached to the disposal.

Sink Drains

Start your search with the part you will see at first sight. It is a sink drain susceptible to blockage, depending on what food waste you dump. So, look for the nearest waste by shining a torch light in the sink drain. Remove the clog-causing agents using pliers.

While you run the garbage disposal to confirm whether the problem still prevails, use another trick by grabbing a plunger.

  1. Place a drain stopper into the sink not attached to the garbage disposal and run the water.
  2. Filled the sink up to 3-4 inches in height and positioned the plunger in the center
  3. Begin plunging up and down three to four times until you notice the clog is loosened.
  4. Remove the stopper and run the garbage disposal with cold water flushing down the drains.

Sink drains are relatively easy to handle without panicking. Remember, you must continue plunging until all the water smoothly goes down the drains.

Garbage Disposal Backing Up into Side Sink Drains

U-shaped Pipe

If you make up your mind to clear all the bugs from the garbage disposal, go deeper and clear blockages that will likely happen in the installation pipes. The first part is a sink trap looking U-shaped, connecting to the tailpiece of the disposal.

You must use an adjustable wrench to remove the stuck debris in this part. Loosen the threaded plug below the sink trap and rinse it with water.

U-shaped drainpipe

Garbage Disposal Elbow

You must check for clogs in the part that connects the drain to the garbage disposal. The simple method is to grab pliers and loosen the elbow. Clean the debris with the water you will find in this piece.

Garbage Disposal Elbow

Tailpiece and Main Drainpipe

Checking every possible part of the pipe is necessary to resolve the issue of garbage disposal backing up into the side sink. Since you have dismantled almost every drain component and reached nowhere, go deep down toward the tailpiece and main drain.

Tailpiece is the vertical pipeline or elongation of the sink drain. Locate the stubborn clogs and grab pliers to remove them. The next piece to be inspected is the main drainpipe, protruding from the back wall underneath the sink in the cabinet.

  1. Run down the plumbing snake into the main drain pipe to the length it reaches the handle.
  2. Turn it clockwise to the time you feel resistance.
  3. Dislodge the clog by pushing the snake further in an anti-clockwise direction.
  4. Remove the blockage and vent it in the bucket.
  5. Clean the plunger snake with water or a towel
  6. Assemble all the parts and check for leaks
  7. Also, remove hot water to wash away the remaining debris.

How Do You Unclog a Sink on the Side of a Disposal?

You can unclog a sink using a variety of techniques. One such is the mixture of baking soda and vinegar. The chemical reaction between acid and alkaline helps clear food items when left in the sink for 20 minutes.

How Do You Know if Sink or Garbage Disposal Is Clogged?

A few symptoms will make you realize your sink or garbage disposal is clogged. While you run the garbage disposal, it drains slowly or sends water back into the sink, the disposal machine generates strange noises, and the motor overheats.

Summing Up

Facing garbage disposal Backing Up into the Side Sink problems in any form is a whole lot of inconvenience. So, avoid it first, and follow the above-mentioned techniques without wasting time. Also, unclogging the various parts of the disposal unit keeps a distance from water coming back into the sink.