Water Is Coming Back Up Kitchen Sink – How to Fix?

If a sink is filling up with wastewater, it’s a sign of water backing up the kitchen sink. There are 5 reasons for water coming back up the kitchen sink. A clog in the kitchen sink drainage system is the most common cause of water backing up.

Water often backs up and accumulates in the kitchen sink due to various reasons such as clogged drains, a broken water line, or even defective garbage disposal. In some cases, it may also be due to a faulty dishwasher.

If you notice water is constantly coming up through your sink, it is important to take action and resolve the issue as soon as possible.

Water Coming Back Up Kitchen Sink

Causes of Water Coming Back Up Kitchen Sink

Clogged vent pipe

Clogged vent pipe

Ventilation is critical to the optimal operation of your plumbing system. Allows the system to take in the air necessary to maintain water flow.

Water may have difficulty moving through your plumbing system if your vent pipes are clogged. Bugs, squirrels, and birds aren’t uncommon in these vents, and their nests might clog the pipe.

Check the roof for any vent pipe obstructions if this is the case. A clogged vent pipe might cause water to come out from your kitchen sink. Hire a professional to clear the line of any debris.

The drain pipe of the kitchen sink is clogged

Food, filth, grease, and hair will wash down the drain using the kitchen sink. Some of the material will be able to move through the pipes without getting clogged. But, there is always the possibility that something will get caught.

This buildup narrows the pipes over time. It makes it more difficult for water to flow through them. It’s only a matter of time before the water comes back up the drain.

Clogging of the sink trap is a common occurrence. Even though the sink p-trap is a helpful plumbing component, it is prone to accumulation.

There comes a time when the buildup is so big that it impedes water flow. As a result, the water in the kitchen sink will begin to back up.

The main drain line is clogged

The main drain line is clogged

Your sink drains are essential to keep your kitchen’s plumbing system clean. If there are issues with the complete plumbing system, they will likely show up before the kitchen sink. As a result, a clogged kitchen sink is more likely to be the source of the issue than the main drain line.

There is still a chance that the main drain line is responsible for the problem. The central drain line, which links to your home’s septic system, collects the waste from your sinks.

A clogged drain can cause a very unpleasant smell, gurgling sink, and water to back up into your sink. It is due to the gunk buildup in the sink drain, coating the pipe’s interior.

The dishwasher is too strong

Have you purchased a brand new dishwasher? One possible explanation for why the water in the kitchen sink keeps backing up is this.

It occurs because your dishwasher and kitchen sink drains into the same pipe. There’s a chance that the water from your kitchen sink could seep back up into the dishwasher as it’s draining it.

Dishwashers use a lot of water at once to do their job well. Some of the water returns to the sink since your pipes may not be able to manage the volume.

Owners who upgrade to a new dishwasher with a powerful pump experience this problem.

The washing machine is clogged

Is your kitchen sink filling up with water when the washing machine is running? If this is the case, the pipe leading to your washing machine is most likely the source of the obstruction.

You’ll need a lot of brute power to clear this blockage out of the pipe. Get a professional plumber to unclog the pipe to avoid damaging your plumbing systems.

If Water Is Coming Back Up into the Kitchen Sink

When you see a sink filling up with water, it can feel like you’re on your own. When a pile of dishes awaits to get cleaned, you think of hiring a professional plumber. It’s a good idea to check out these simple ways to first clear a drain on your own.

Use boiling water

Oils, soap residue, and other debris can clog a drain if they become lodged in the pipe. To clear clogs and restore proper operation to your system, you need to use hot or boiling water.

You’ll need to bring the water to a boil and then pour it into the sink. You can use boiling water to remove clogs in your sink. The boiling water will remove grease and other clogging substances.

Tools Required:

The process of unclogging a kitchen sink using boiling water is not that complex. It requires everyday household things that you can use to perform this task. The essential tools that you need are:

  • Kettle/Pot
  • Stove
  • A Mug

There are several ways to solve this problem, but this is the simplest and least expensive. You can perform it by following these steps:

Step 1: Boil the water

To perform this step, you need to boil the water by putting it in a pot or kettle. Afterward, put the pot or kettle on a stove to boil the water.

Step 2: Clear out water from the sink

After putting the water on the stove, you need to clear the water present in your sink. While you wait for the water to boil, you can use a mug or small pot to remove the water from the sink. You’ll clear the sink and make a pathway for the boiling water.

Step 3: Pour the boiling water

Now that you have removed the water from the sink and the water on the stove is boiling. You have to pour that mixture into the sink. After pouring it down the kitchen sink, you need to wait for a few minutes.

Step 4: Take out cooled water

Scoop out as much of the cooled water as possible. Afterward, dispose of it in another sink or toilet once the water has had time to cool for around five minutes.

Step 5: Repeat the process

Do it all over again. Even if you have to repeat the process several times. This method is often successful to stop water from backing up in the sink.

If you see the sink is clear, there is no clog left in your kitchen sink. If you still see water in the sink after emptying the kettle, you need to use another method.

If your drain is connected to PVC pipes, you should avoid using this procedure. It is because boiling water could melt or damage the plastic.

As soon as the second attempt with boiling water doesn’t work, it’s time to try something else. Unfortunately, the basic solution of boiling water hasn’t worked for your sink blockage.

Remove the blockage by plunging

Remove the blockage by plunging

If you see black water backing up in the kitchen sink, it’s time to use this method. Once you know the disposal is not the problem, you need to use a plunger. Remember, we recommended using a flat-bottomed plunger for this method.

Tools Required:

The clog removal using the plunger does not need many materials. There are a few materials that you need to perform this method:

  • Plunger
  • Towel
  • Newspaper
  • Bucket
  • Cleaning Liquid
  • Rubber Gloves
  • Penetrating Oil

Follow these steps while holding a plunger in your hand:

Step 1: Prepare the area

Protect the kitchen floor by surrounding the sink with old newspapers and towels to catch spills or leaks. Do not use your finest towels yet.

A bucket should be ready to go if necessary to remove a blockage by pulling it up rather than pushing it down. Protect yourself by using rubber gloves and a change of clothes.

Step 2: Try to prevent overflows

You must turn the shutting valve to prevent the objects from overflowing. You’ll find it under the kitchen sink on a pipe coming out of the wall.

Make sure you don’t break it if it’s not moving and you’re using too much force when turning it clockwise. You can loosen the valve by spraying it with penetrating oil.

It may not work, or your sink may be ancient and lack a shutoff valve, in which case your options are to deal with the float or flapper in your sink.

Use a mug or pot to remove the water present in the sink. Make sure there is nothing else in the sink that will make it difficult for you to perform this method.

Step 3: Double-check your plunger

If the obstruction is a toy for a child or another object, first see if you can remove it without the plunger.

It’s time to pull out the plunger if that’s not true. It would be best to use the correct plunger. You need to use a plunger that isn’t retractable for your kitchen sink.

You won’t have a tight seal around the hole if you use an improper instrument. This task will be more complex and take longer. Ensure that the plunger is in the right position before you begin plunging.

Step 4: Plunge

First, push firmly down to create a seal to remove the impediment, then quickly pull up to release the seal. You’ll see the water drain as soon as you crank up the pace. Unclogging a kitchen sink can take anywhere from 15 to 30 minutes.

Dislodging and pushing forward, the blockage might happen when draining. Refill the sink with water to the desired level. If this doesn’t work, try again. Plunging may be necessary for difficult clogs containing hair or moist wipes.

Take help of a natural drain cleaner

In most cases, conventional drain cleaners don’t clean drains as well as they claim to. These drain cleaners contain dangerous chemicals. You can clear the clogs can with vinegar and baking soda, depending on the severity of the blockage.

Tools Required:

In making a natural drain cleaner, You may need some basic things. Here is a list of essential things when making a natural drain cleaner.

  • Cup
  • Bucket
  • Drain stopper
  • Boiling water
  • 1/2 cup Baking soda
  • 1/2 cup white distilled vinegar

Here are the steps you need to perform to unclog a kitchen drain using a natural drain cleaner.

Step 1: Take out standing water

Pour as much water as you can out of a backed-up sink using a cup and emptying it into a bucket. To reach the blockage, you’ll want to keep a tiny quantity of water in the drain opening.

Step 2: Add the boiling water

Get a better look at your sink by first dismantling the stopper on your sink. Drain the sink with a small amount of boiling water.

Step 3: Add baking soda

You need to pour the half cup of baking soda into the sink.

Step 4: Add vinegar

Pour a half-cup of vinegar down the pipe.

Step 5: You need to cover the sink

Cover the sink and allow the combination to work for 10 minutes. When using baking soda and vinegar, you should cover the sink to prevent fizzing and bubbling. However, it isn’t necessary to cover it.

Step 6: Add boiling water again

To flush the sink, add another pot of hot water. The vinegar and baking soda will loosen up any clogs in the pipes, so this will assist flush them out.

Step 7: Clear the sink

Now, you need to remove any remaining material from the drain pipe. You can do so by removing p-trap under sink.

Step 8: Repeat the steps as needed

Even if your drain is slow or clogged, this low-cost cleaning solution may take several tries. If you see some improvement after the first use, give the drain cleaner another shot. Try a more radical option if the drain is still too slow after several attempts.

Consider dismantling the drain trap, if possible, and using a drain snake if this cure fails to free the clog. Before removing the trap, place a bucket under it to catch any water that may leak out.

Using a DIY drain cleaner is convenient because you don’t have to worry about toxic chemicals spilling into the water. Calling a plumber may be necessary if drain cleaning does not work.

How to Keep Kitchen Sink Drain Clear

Keeping Kitchen Sink Drain Clear

Here are some tips for keeping your kitchen sink drains clear.

Tip 1: Use a mesh drain strainer

Using a mesh drain basket or a strainer is an easy and low-cost technique to avoid clogs. Rather than flushing away, non-liquids will clog the trap.

Remove the trap and discard the collected solids in your garbage. You can find simple, affordable drain traps at any home improvement or hardware store.

Tip 2: Avoid pouring grease

Grease from cooking immediately solidifies in your drain. Using a can or disposable container, dispose of the used cooking fat.

Tip 3: Never flush food scraps

Limiting what you flush down the garbage disposal is an excellent strategy. It helps to keep your kitchen drain clear and free of obstructions. The best way to avoid kitchen clogs is to scrape food waste into the trash bin before rinsing dishes.

Tip 4: Clear clogs with natural solutions

Chemical cleaners can damage your kitchen pipes. Using baking soda and vinegar can be the best way to clean your sink pipes. Pour hot, nearly boiling water down the kitchen sink. Allow it to sit for about 20 minutes after adding 1/4 cup baking soda.

Pour a cup of vinegar and boil water over the top, and stir well. Pour hot water down the drain for another 20 minutes.

If you have a tiny clog in your drain, this may be able to dislodge it. If it’s been there for a while, you may need a plumber or a plunger to get it out.

Water Coming into Kitchen Sink from Washing Machine – How to Fix?

Step#1: Cleaning the Waste Line

You may eliminate the obstruction by plunging the sink, but you must do it when the water is backing up, and the pipes are full.

To optimize the force of the plunger, you should plug the overflowing holes and the drain. If there is a nearby toilet, it might be prudent to plunge it since the obstruction may be nearer to it than other fixtures.

Step#2: Venting Problems

The sink and washing machine each have vents extending through the walls and linking to the main vent stack. The problem may be a clog in the main vent stack. If plunging has no impact, the roof vent opening is the following location to inspect.

You may discover leaves or sticks obstructing the aperture. Eradicating them might address the issue. By pouring water into the vent hole, it is possible to test if the vents are open. It should not back up regardless of how much water is sprayed.

Step#3: Studor Vents

If you installed your washing machine relatively recently, the plumber might have used a Studor vent to vent the drain line. This vent, also known as an air admission valve, eliminates the need to install new vent pipes.

Negative pressure makes a spring-loaded valve open up to allow air in and maintain water flow; nevertheless, the valve can become stuck.

Thankfully, it is simple to replace. It is attached to the drain just behind the washing machine. Use adjustable pliers to unscrew it and replace it with a new one.


Here’s all you need to know about water coming back up kitchen sink. I’ve also included instructions on how to clear the drain pipes on your own.

Kitchen sinks could get clogged for a variety of reasons. It’s a huge turnoff when you see your kitchen sink overflowing with water. I’ve discussed all the required advice to avoid these kinds of problems. If you follow these guidelines, your kitchen sink will be free of clogs and water will drain easily.

Lisa Burks

This is Lisa Burks, the Author. I provide free informative sink and faucet guides. I hope you love your time here.

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