Do you have a double sink that is clogged? Double sinks require special considerations thanks to the two separate drains and the extra-large size. You need to start by setting yourself up for success by preventing clogs in the first place.
Let’s talk about how to unclog a double kitchen sink the right way.
In this PlumbingNav guide, we will cover:
How your double kitchen sink works
Causes of kitchen sink clogs
Preventing clogs in a double kitchen sink
How to unclog a double kitchen sink
What's In This Guide?
How Your Double Kitchen Sink Works
Your double kitchen sink is very similar to a standard single basin kitchen sink except it’s bigger and gives you two different drains. It’s also common for side of the sink to have a garbage disposal attached to the drain.
As opposed to a single tailpiece connecting the single sink directly to the P-trap drain, each sink in a double sink has its own tailpiece that connects to a sanitary tee, which in turn connects to the P-trap drain.
Water then flows down your sink drain to your main drain, and finally out your sewer system until it connects to the city sewer line. Waste water gets transported to the city treatment center (unless you have a personal septic system). This illustrates that a clog may develop in different parts of your system, but we’ll start with the easiest to reach.
Causes of a Clogged Drain at Your Double Kitchen Sink
Here are some of the main causes behind a clogged kitchen sink drain. Some you can avoid putting down your drain, but others just happen over time.
Grease and Fat
One of the largest culprits in kitchen sink clogs is grease and fat. People may allow cooling oil or bacon grease to go down the drain after cooking. Unfortunately, the grease and fat will stick to your pipes and solidify, picking up other debris, too. See this post where we answer the question, “Can You Pour Oil and Grease Down the Drain?”
While many people may attempt to clean a grease clog with hot water, it may only liquefy the greasy clogs temporarily and cause it to move further down the sewer drain line.
To properly dispose of grease and fat, collect the waste in a clear container and throw the container out in the garbage when full.
Sediment Buildup
All water contains minerals, especially hard water that leaves calcium buildups. The minerals can get left behind in your pipes and create a clog in your pipes.
If you have hard water, you will experience more sediment buildup than in soft water conditions. Sediment buildup also occurs more often when you have hot water and high water pressure.
Food Waste
A garbage disposal can make cleaning up after cooking easier by cutting up food waste into small easy-to-dispose of bits. However, improper use of the garbage disposal can lead to plumbing trouble. You can’t just put anything down the garbage disposal!
Follow these simple steps on how to unclog a double kitchen sink.
Step One: Prep
Prep your kitchen sink by removing all items from your nearby kitchen counter. You should also remove the items from underneath your sink just in case.
Get all of your supplies ready, too. You’ll need basic tools as well as whatever plumbing tools you need for your project, such as a plumbers snake or sink plunger.
Finally, verify if the problem exists in both parts of your double kitchen sink or only one part of the sink.
If you have a problem with only one side of the sink, you have a sink clog at the very top of your drain.
If both sides of your sink are clogged, there may be a problem with your P trap or grease trap. If you also notice a problem with your bathroom sink, you may have a problem deeper in your plumbing system or have a main line sewer clog.
Step Two: Clean Your Garbage Disposal
If the side of the sink with the garbage disposal is giving you trouble, you may need to clean the garbage disposal.
Start by turning off the garbage disposal. You can hurt yourself badly if you accidentally turn the garbage disposal on while you clean it. Turn off the power at the circuit breaker for added protection. This is a must.
You can then stick your hand down the garbage disposal to clear out anything stuck.
Step Three: Clean P Trap and Grease Trap
Your kitchen sink has a P trap designed to hold water to keep sewer gas from coming back into the house through the drain hole. P traps are required for every kitchen sink drain by residential building codes. There’s always a small amount of water in the P trap to help regulate air flow in your plumbing system, but this bend can accumulate gunk.
To clean your P trap, you first need to turn off the water supply to prevent yourself from accidentally turning it on. Next, you will need to remove the P trap by unscrewing it from the drain pipe. After you remove it, you’ll clean it and reattach it firmly. Pour a small amount of water down the drain, watching for leaks to ensure it’s tight.
If you have a grease trap, you should use this opportunity to clean it out as well. Grease traps require regular cleaning not only to prevent a clog but also to prevent a hazard as grease is flammable. You can clean a grease trap yourself.
In order to clean your grease trap, you will open your grease trap and scoop out the grease and solids. Remember to dispose of the grease properly.
In many cases, this step will lead you to the heart of the problem. Here is a video demonstrating a typical double kitchen sink setup. You can follow along with each step to locate the clog.
Step Four: Use a Natural Drain Cleaner or Chemical Drain Cleaner
Caustic drain cleaners can create a drain opening, just be sure to read the label. You should also be sure to use chemical drain cleaners sparingly.
Step Five: Use Electric Drain Snake
An electric power drain snake is a tool that maneuvers into your plumbing until it reaches the clog. The end will turn and break up the clog at the source.
Electric drain snakes only reach about 25 – 50 feet down your drain and may not reach the deepest clogs. Furthermore, not all homeowners have their own electric drain snake.
How to Prevent Clogs in a Double Kitchen Sink
There are plenty of tools to help you prevent clogs in your double kitchen sink.
Drain Strainers
A drain strainer is a product that fits into your kitchen drain made up of small holes that allows water to flow through but catches larger items. You will remove any waste caught in the drain strainers and throw it out in the garbage.
A grease trap is a type of drain trap or sink trap that connects to your kitchen drain and collects grease before it flows down your drain.
You can install your own store-bought or homemade grease trap if you don’t already have one attached to your plumbing.
Regular Drain Cleaning
As part of your regular plumbing maintenance, you should perform regular drain cleaning with a natural drain cleaner or Sani Stick.
Natural drain cleaners use natural enzymes to break up organic materials instead of the harsh chemicals in caustic drain cleaners.
These products can’t break up stubborn clogs, but they can maintain your pipes to prevent clogs before they turn into something larger without damaging your pipes. See our Green Gobbler review for more on this.
Problems Caused By a Double Kitchen Sink Clog
You may not realize just how much more damage a clogged sink can cause in your plumbing system beyond the frustration of waiting for standing water to drain. However, there are some additional problems to be aware of.
Mold
Standing water in your pipes and warm temperatures can promote mold development if you have food waste in your pipe. Soon, the mold can grow and cause a bad odor from both sides of your double kitchen sink. Furthermore, if mold begins to spread it can emit toxins into your home.
You will probably smell mold in your pipes before you see it. Once you see it, you need to perform mold removal and cleanup right away.
Leaks
When you have a clogged drain pipe, your plumbing system requires more pressure to move waste properly. The added pressure can take a toll on the pipes and eventually create a leak.
Even a small leak can result in huge expenses in wasted water. However, small leaks never stay small for long. The leak will continue to grow until it causes more damage. Read this post about water leaks under the slab.
Increased Corrosion
If you have a clog that results in standing water stuck in your metal pipe, it will accelerate corrosion, deteriorating your pipes before the expected lifespan. However, this risk is reduced when using plastic PVC pipe or PEX pipe.
Slow Drain
When you have a clog further down the pipes, you also probably have a slow drain. A slow drain can lead to hard water stains in your sink thanks to the standing water in the sink as it slowly drains. It can also create more soap scum on your dishes and more calcium deposits around your faucets. Avoid pouring bleach or other harmful chemicals down your drains, as this will cause more damage that help to you.
Final Thoughts on How to Unclog Double Kitchen Sink
A clogged kitchen sink can be a serious frustration. A double kitchen sink with a garbage disposal can be especially difficult to deal with. We hope this guide helped you identify the cause and location of the drain clog and move forward using the tips we provided.
If you can’t resolve it, you will need to enlist the services of a professional plumber before the clog worsens resulting in more expensive repairs.
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About Plumbing Navigator
We write about "all things plumbing," helping you navigate common questions, repairs, and the best plumbing products on the market.
About Plumbing Navigator
We write about “all things plumbing,” helping you navigate common questions, repairs, and the best plumbing products on the market.
