3 Reasons Your Dishwasher Backing Up Into Sink!

By - Ron Singh

Updated -

Dishwashers are the perfect kitchen appliance for large families and busy homeowners. Their ability to ease you from staying up late to do the dishes is a superpower.

Unfortunately, it is rather unpleasant when you step into the kitchen and notice the sink overflowing.

It is even more disturbing when there is a smell. But, of course, it is only natural to search for a solution as soon as possible. 

The various reasons why your dishwasher backs up into the sink are mainly because of clogs. If the dishwasher’s drain has clogs from food particles, it will result in a full sink. Furthermore, if something is in the garbage disposal, you have your culprit. As long as you remove the obstruction, everything goes back to normal.

You might wonder how to fix it. Consequently, there are some causes and a plethora of affordable solutions.

Why is my dishwasher backing Up Into the Sink?

Dishwasher Backing Up Into Sink

Your dishwasher might back up into the sink due for various reasons. Some might be minor, and others may require more attention than others.

In the end, the goal is to have a properly functioning dishwasher. But, of course, before you fix a problem, you must discover its reasons.

This rule applies to dishwashers too. So, here are the possible reasons why your dishwasher is backing up into the sink.

#1. The Clogs Situation

Clogs are the significant reason the dishwasher backs up into the sink. Knowing what the phrase backing up means would be the best way to understand this topic further.

When a dishwasher backs up into the sink, it means that wastewater from the dishwasher cannot go through. Consequently, it comes back and stays inside the sink.

This problem is common because it does not take a lot for clogs to get stuck in the drain. Usually, a dishwasher and the sink share a drainage system.

It means that after a wash cycle in the dishwasher, water flows from the dishwasher to the kitchen sink.

Now, if the sink drain has clogs, the water will back up and create a messy situation. Clogs are not unnatural or rare; on the contrary, they are usually in an active kitchen.

Examples of clogs are:

  • Food particles from scraps
  • Soap particles during washing
  • Debris
  • Buildup from a mixture of food and soap particles

In addition, there are specific places where you can find clogs, so you know where to look. For instance, it would be absurd to look in the vent when you notice that your sink is overflowing.

The familiar places for finding and removing clogs are:

  • At the base of the dishwasher
  • In the sewer line under the sink
  • The sinks drainage
  • The dishwasher’s drain
  • The garbage disposal 

These places are ideal spots where small undegradable particles sit and wreak havoc in your kitchen.

#2. Dirty Dishwasher Filter Basket

The dishwasher filters help remove excess particles from going into the drain. If the food bits keep accumulating, this will lead to a blocked drain hole.

Consequently, the dishwasher will not pass water after a wash cycle, and the dishes will remain dirty. Before long, the water will go slowly to the sink drain.

 It is very unhealthy because those particles encourage mold growth on the dishes. This problem occurs if you clean the dishes after you take them out.

#3. Garbage disposal Problem

A few problems with the garbage disposal affect the dishwasher negatively.

Here are a few of them.

#1. Plastic Plug Problem

The garbage disposal is under the sink and connects to the dishwasher. It helps to shred food particles into smaller bits to allow them to pass through the sewer line.

During installation, you ought to remove a plastic plug that can become an obstruction in the future. This plug can block the water from passing into the sink line.

#2. Dull Disposal Blades

If the garbage disposal blades go wrong, fix a new one. Dull blades will make it tougher to shred particles.

Subsequently, the improperly shredded particles will clog the drain and make the water back up the sink.

How Do I Stop the Backflow in My Dishwasher?

Once you locate the cause of the problem, you can stop the backflow of water in your dishwasher.

Since you know the various reasons why your dishwasher is backing up into your sink, here are the solutions. 

Remove Clogs from the Dishwasher Drain

Removing clogs in the dishwasher drain is the best way to remedy them manually.

To do this, here are a few steps.

  • Please turn off the dishwasher and unplug it from the socket.
  • Next, remove all the dishes from the rack to create room.
  • Locate the drain at the base of the dishwasher.
  • Wear some gloves and remove the particles from the drain.
  • Disconnect the dishwasher’s pipe to the sink and flush with warm water.
  • Connect the line back and run a cycle. This action should fix the problem.

However, you can do this if there are clogs in the sink line.

  • First, turn off the garbage disposal unit.
  • Wear some gloves and reach into the sink drain for any particles.
  • Take out the ones you can find and flush the sink with hot water and vinegar.
  • Please, desist from using liquid dissolves as they damage your sewer lines in the long run.

Why Is Water Backing Up in the Dishwasher When Not in Use?

Water backs up in the dishwasher when not in use for several reasons. Here are some of them:

  • Food particles in the dishwasher drain after a wash cycle is another primary reason.
  • Low dishwasher water pressure.
  • Low house water line pressure.
  • Food particles in the filter basket can cause the dishwasher to go back into the sink.
  • Water is leaking into the dishwasher from the inlet valve.
  • Clogs in the sink line.

Although the dishwasher drain and filter basket perform similar roles, there are specific differences.

The table below highlights a few differences and unique features.

Filter BasketDrain 
It has a mesh that captures particles.It has a hole that allows water to pass through.
You can remove it to clean it correctly.You can only remove the pipe that connects it to the sink line.

How Do You Clean Out a Dishwasher Drain?

The best way to clean out the dishwasher drain exists and works perfectly. So, if you wish to know this, keep reading.

Here are the following steps to clean out a dishwasher drain:

  • First, make a solution of water, vinegar, and baking soda. These chemicals help to break down the particles faster and easier.
  • Then, pour the mixture into the drain and let it sit for about 30 minutes.
  • Afterward, run a cycle and note the differences. This action should dissolve any particles that are in the drain.

In addition, you can flush it with hot water to further help the breakdown process. Hot water dissolves particles by dissolving their molecules.

In addition, ensure to scrap food particles from the dishes properly before loading the dishwasher.

This way, you will rarely encounter problems related to clogs. Remember that if you treat your gadget right, it will serve you longer.


The dishwasher backing up into the sink is mainly because of clogs in the drain or garbage disposal unit. However, you can fix this problem quickly.

Also, it would be best to clean your dishwasher regularly to avoid such problems. If you do so occasionally, your dishwasher will work more efficiently.

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