Have you ever wondered why the kitchen sink gurgles when the washing machine drains its water?
Generally, your washing machine, bathroom sink, toilet, and even kitchen sink usually share the same waste pipe.
Once done washing, the washer will release loads and loads of water down the drain.
If there is any blockage along the drain, then a gargling sound will be produced by the sinks.
This happens when the water drains from the machine since there is not enough space for the large volume of water to escape.
So, what makes the kitchen sink gurgle now and then? Is it something you should be worried about? Can you fix it on your own?
Here are a few possible reasons why this might be happening:
- Clogged or Partially Blocked Drain: If there is a partial blockage in the drainpipe shared by both the sink and the washing machine, it can cause water to drain more slowly. As the washing machine pumps out water, the pressure change can draw air through the sink’s water trap, resulting in the gurgling sound.
- Venting Issues: Plumbing systems are designed with vent pipes that allow air to enter and exit the drainage system, maintaining proper pressure and preventing gurgling noises. If the vent pipe is obstructed or blocked, it can disrupt the air balance, causing gurgling sounds when water is drained from the washing machine.
- Insufficient Drainage System: In some cases, the plumbing system may not be adequately sized or designed to handle the simultaneous drainage of the washing machine and the sink. This can lead to increased pressure and air displacement, resulting in gurgling sounds.
To address this issue, you can try the following steps:
- Check for clogs: Inspect the sink drain for any visible blockages. Use a plunger or a drain snake to clear any obstructions. If the problem persists, you may need to call a professional plumber to assess and clear the blockage.
- Verify vent pipe functionality: Ensure that the vent pipe connected to your plumbing system is not obstructed. If you suspect a problem with the venting, it’s best to consult a plumber for a thorough inspection and necessary repairs.
- Seek professional help: If the gurgling issue continues despite your efforts, it’s advisable to contact a licensed plumber. They will have the expertise and tools to diagnose and resolve the underlying problem with your plumbing system.
In this guide, I will explore all the reasons why the kitchen gurgles when the washing machine drains.
I will also review some of the possible solutions to the problem.
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Why My Kitchen Sink Gurgles When The Washing Machine Drains: Reasons And Solutions
For your kitchen sink to gurgle when the washing machine drains, it simply means their drainage systems are connected to some point.
The gurgling sound from your sink is air from the drainage, which is escaping caused mainly by the pressure difference in the pipes.
If your vent functions normally, the air will not be trapped; instead, it will comfortably escape via the vent.
But if it is blocked, there will be an air build-up.
Therefore, once some significant volume of water is released into the drain, the air will find its way out, and the sink will be the only choice.
So, why does the kitchen sink gurgle when the washing machine drains?
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1) Kitchen Vent Pipes Which Are Blocked.
If your washing machine is near the kitchen, they most likely share the drain with the kitchen sink.
The gurgling sound from your kitchen sink results from the vent being blocked.
So when the washing machine water is draining, the air in the vent will be pushed by the water, and because the vent is already blocked, the air will escape via the sink and thus the gurgling sound.
The sole purpose of the vent pipe is to allow the sewer gas to escape.
If it is blocked, then gurgling of the sink, bathtub, the toilet will take place.
Vent pipes run all the way to the roof of your house, where the sewer gas is vented out.
For you to establish if the vent system of your home is blocked, here are three signs to spot;
- Strong bad odors from the drain
- The gurgling of the sink, toilet, bathtub
- The speed at which water drains
2) Poor Installation Of The Vent Pipes
Poor installation of the sink vent pipe is the first suspect when it comes to the gurgling of the sink.
If your sink is newly installed and it’s gurgling, then the pipes have not been installed as expected.
Routing of pipes correctly and proper joining of the vent pipe is vital.
If your sink drain uses the 1.5-inch drain pipe, then automatically, the vent pipe should be installed at a minimum of 3.5 feet away from the bottom of the trap.
This correct spacing allows the vent to pump sufficient air, thus creating the much-needed pressure difference in the plumbing system.
If the air is not well balanced inside the vent, then when the washer releases water with a lot of pressure, the vent will not regulate the air, so the gurgle will happen inside the sink.
In addition, you might also find that the plumber who installed your venting machine used a stud or vent to help vent the drain from the washer.
Studor vents are a workaround for not running new vents through the wall.
3) Damaged Or Leaking Vent Pipes
Like blocked vent pipes, a leaking vent can upset the pressure inside the drain system.
Low pressure will affect the correct flow of water and air inside the plumbing system.
When pressure is low, the air inside will automatically not get out as it should through the vent, but rather it will escape via the kitchen sink.
The air escaping through the sink creates a gurgling noise when draining the machine.
4) Clogged Main Vent
Like the clogged kitchen sink vent, a clogged central vent can be much more problematic.
Since it’s the main vent, it usually regulates air pressure throughout the drain system, and if any blockage happens, the pressure will increase too.
Therefore, the air will eventually be trapped in the main vent pipe when the washer starts to drain its water via the drain connected to the sink drain.
Since the central vent is blocked, the air will escape via the sink drain, and that’s why your kitchen sink produces gurgling sounds.
How To Fix A Kitchen Sink That Gurgles When The Washing Machine Drains
Identifying the specific sink that is gurgling in your house is the key to finding a solution to the problem.
A gurgle in your kitchen sink is directly related to issues in the drain or the sink pipes most of the time.
To help prevent a gurgling sink, it’s important to address the underlying plumbing issues that can cause the problem.
Here are some preventive measures you can take:
a) Flush The Main Vent.
In many cases, the washing machine and the kitchen sink usually share a vent that then joins to the main vent, which extends to the roof of your house.
In cases where each has its vent connecting to the main one, the reason for your sink to gurgle when the washer is emptying originates from the main vent.
You may find trash such as tree leaves, dust, or even broken tree branches having clogged the vent, thus altering the pressure inside the system.
Clear the debris then, using a pressurized pipe, blow water inside the vent to confirm it’s clear.
The water should not back up no matter the volume you have sprayed.
Always note this exercise is risky, therefore calling a professional would be ideal.
b) Replace The Studor Vent
Stud or vents, also known as the air admittance valve, are commonly used to replace sink vents.
It is not advised to u
Lack of venting means there will be gurgling of toilets and sinks non-stop.
Studor vents are nowadays preferred as they significantly reduce the number of items needed for plumbing.
They are easy to install and reduce the number of roof repairs that might be required after roof vent repair.
Once a stud or vent is clogged, you can easily replace it by yourself by just unscrewing and re-screwing back.
In addition, they are not as expensive. They range between USD 10 to USD 20 and can last a minimum of 20 years.
c) Clear The Draining System
If you have confirmed that your p-trap, the main vent from the roof, and the stud or (air admittance valve) are all okay, then it’s high time you tried a simple fix such as running hot water down the drain.
A minor clog down the drain may be the reason why your sink is gurgling. A clog means the drain cannot handle a lot of water from the washer.
In most cases, partial clog with time will always lead to complete blockage of your drainage.
Water draining more slowly than usual plus the gurgling of the sink are all indications of blockage of your main drain.
On the other hand, drain cleaners such as the Rid-X drain cleaner are really effective and environmentally friendly.
Green gobbler is also another enzyme-based cleaner that is quite effective.
Put some of the cleaners in your bathtub drainer, kitchen drain, and washer drain, and let it stay overnight.
Ensure they are not used at night too. The cleaner eats the soap remains and other organic things along the drain. This will make it easy to flush any other gunk.
You can use it often till the gurgling is clear, and after that, you can use it every three months.
It is safe and environment-friendly.
d) Fix The P-Tap
A P-trap is a U-shaped pipe beneath your sink.
It contains water which serves as a barrier to gases from the sewer to your home.
If a P-tap is not well installed, then a vacuum will be created. The created vacuum will pull all the water from the P-trap, so the sink’s gurgling will take place.
For instance, if the drainpipe is 1.5 inches long, the vent should be placed 3.5 feet from the lowest part of the p-trap.
e) Thoroughly Wash Your Drain
In case the flushing of the drain does not work, it is now time to clean the drain.
Irrespective of how careful you are regarding food debris disposal, some will always go down the kitchen sink.
For those who use water from wells and boreholes, the mineral build-up can cause a problem on the drain.
With a basin placed under the P-trap, open it and clear the water inside it. Clean it and put it back.
Can the washing machine drain into a sink?
In some cases, a washing machine can drain into a sink. However, whether or not this is possible depends on the plumbing setup and local building codes in your area. Here are a few scenarios where a washing machine may drain into a sink:
- Utility Sink: In some homes or laundry rooms, there may be a utility sink or laundry sink specifically designed to receive the discharge from a washing machine. These sinks typically have a larger drain and are connected to the plumbing system to handle the wastewater from the washing machine. The sink acts as a receptacle for the drained water.
- Shared Drain Line: In certain plumbing setups, the washing machine and sink may share a common drain line. This means that both the sink and the washing machine discharge into the same drain pipe. In such cases, the drain pipe is typically sized to handle the combined flow of water from both sources.
It’s important to note that local building codes and regulations may dictate whether or not it’s permissible to connect a washing machine drain to a sink. It’s always advisable to consult your local building authority or a licensed plumber to ensure compliance with applicable codes and regulations.
If you’re considering connecting a washing machine to a sink, it’s crucial to ensure that the sink’s drain and plumbing system can handle the increased volume and flow of water. Additionally, proper plumbing connections and traps should be installed to prevent backflow and sewer gas from entering your home.
It’s recommended to consult a professional plumber to assess your specific plumbing setup and provide guidance on the feasibility and proper installation of a washing machine drain into a sink.
Why does water come up the sink when the washing machine is on?
When water comes up the sink when the washing machine is running, it typically indicates a plumbing issue. Here are a few potential reasons for this problem:
- Clogged Drain Line: One common cause is a clogged or partially blocked drain line. Over time, debris, soap residue, and other substances can accumulate in the drain pipes, leading to reduced water flow. As the washing machine pumps out water, the restricted drain line may not be able to handle the volume, causing water to back up and emerge from the sink.
- Venting Problems: Plumbing systems are equipped with vent pipes that allow air to enter and exit the drainage system. These vents help maintain proper pressure and facilitate the smooth flow of water. If there is a blockage or obstruction in the vent pipe, it can disrupt the air balance and cause water to back up into the sink when the washing machine is draining.
- Shared Drainage Line: In some cases, the sink and washing machine may share a common drain line. If the drain line is not adequately sized or designed to handle the simultaneous drainage of both appliances, it can lead to water backing up into the sink.
To address this issue, you can take the following steps:
- Check for Clogs: Inspect the sink drain and the drain line shared by the sink and washing machine for any visible blockages. Use a plunger or a drain snake to clear any obstructions. If necessary, consult a professional plumber to thoroughly clean the drain lines.
- Verify Venting System: Ensure that the vent pipe connected to your plumbing system is not obstructed. If you suspect a problem with the venting, it’s best to consult a plumber for a thorough inspection and necessary repairs.
- Seek Professional Assistance: If the problem persists or you’re unsure about the underlying cause, it’s advisable to contact a licensed plumber. They will have the expertise and tools to diagnose and resolve the plumbing issue effectively.
Remember, plumbing problems can vary, and it’s crucial to address them promptly to prevent further damage. A professional plumber can provide an accurate diagnosis and recommend appropriate solutions based on your specific situation.
Final Thoughts On Why My Kitchen Sink Gurgles When The Washing Machine Drains
Kitchen gurgling is always an indication something is not correct.
It is also not new for the kitchen sink and washing machine to share a drain.
Therefore if your kitchen sink gurgles when the washing machine drains, then something is blocking the flow of the water or something preventing the air from getting inside the drain, or both.
Therefore a gurgling sink should not be ignored since, in the end, it may cause a disaster to the whole drain.
A clog, improper installation, or even blockage are some of the reasons why the kitchen sink gurgles when the washing machine drains its water.
Here are some FAQs:
Q: Why is there a nasty smell coming from my sink?
A: A nasty smell coming from the sink is often caused by sewage gases, which can occur when the drain or vent is blocked. This can cause the gases to escape through the sink instead of moving into the sewer. Checking the air vent and drains for blockages is recommended.
Q: Can I pour bleach down a washer drain or any other drain?
A: It is not recommended to pour bleach down a washer drain or any other drain. Bleach can react with other substances, such as vinegar and ammonia, and produce harmful fumes or potentially clog the system. Additionally, it can kill the beneficial bacteria in septic systems.
Q: What are the signs of a clogged washing machine drain?
A: If the washing machine drain is clogged, you may notice water backing up and not draining away properly. After the spin cycle, there may still be water in the tub and your clothing may remain wet.
Q: What is the best product to unblock a kitchen sink?
A: Drano is a commonly used product to unblock a kitchen sink. It is known for its effectiveness, affordability, and ease of use. However, it’s important to note that Drano is a chemical that can be harmful to the environment and may potentially damage pipes.
Q: What is a P-trap and where is it located?
A: A P-trap is a curved section of pipe, typically made of white PVC, located underneath the sink between two nuts. It has a U or P shape when viewed from the side. The P-trap is designed to trap water, preventing sewer gases from entering the living space.
