Kitchen Sink Won't Drain But Not Clogged? (Fix It Now!)

Jessica Stone
by Jessica Stone

If you have a kitchen sink that won’t drain, you’re not the only one who has experienced this inconvenience. If you’ve exhausted all possible methods to unclog your sink and are still having issues, we have a solution for you. Even if you think that you successfully cleared out your pipes, there is likely still a clog preventing your kitchen sink from draining.

When your sink isn’t draining but the pipes are clear, start by pouring boiling water down the drain. Other DIY solutions are clearing out your garbage disposal, using a plunger, and employing a vinegar and baking soda mixture. You can also utilize a plumber’s snake, clean out your P trap, and use eco-friendly drain cleaners to address the issue.

If none of these steps seems to make a difference, then it’s best to call a plumber and have them take a look. Regardless, we’ll explore all of the techniques you can easily implement yourself to successfully force your kitchen sink into properly draining again.

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Three Main Issues That Lead To Sink Not Draining

In most cases, even when pipes appear to be clear, there is a hidden clog preventing the sink from draining. Read on to learn about each of the three main issues that cause your sink not to drain properly.

1. Pipe Angle

The first common problem that prevents proper sink drainage is an improper pipe angle. Pipes must be installed at specific angles in order for drainage to flow properly. When they aren’t at the right angle, all sorts of problems can occur.

These problems range from a buildup of standing water to slow drainage and clog formation. Due to the angle of the pipe, flowing water is unable to flush out built-up debris. As a result, it gets worse and worse. Eventually, the sink will stop draining entirely.

Take a look under your sink to see if the pipe angle could be the culprit. Ideally, a pipe should have a slope of ¼” for every foot it travels horizontally. If any pipes appear to have too little or too much of a slope, that could be the cause of the issue.

Once you’ve identified pipes with problematic angles, the short-term solution is to remove them and clean them out thoroughly. However, this is really only a “band-aid” for a bigger issue. For a lasting solution, you’ll want to hire a reputable plumber to replace the pipes and ensure they’re at the correct angle.

2. Clogged P Trap

So, your sink isn’t draining but the pipes are clear. At least, that’s how they appear. Unfortunately, there may be a clog hiding in your P trap, the elbow-shaped bend in the pipe. The P trap often collects grease, food, hair, and other gunk and can easily become clogged.

The solution here is to remove and clean out the P trap. We’ll go over the details of how to do this later in the article.

3. Clogged Air Vent

Sinks usually have built-in air vents that help water flow smoothly through the pipes. But a common issue is the air vent getting clogged with various types of debris. Depending on local building codes and your particular sink, the vent may be located in a different area, but it’s usually under the sink.

To identify the air vent, look for a seemingly random pipe that has no attachments. Remove it and check for clogs inside of the piping. If there is buildup inside, clean it out thoroughly, reattach the vent, and see if the problem is solved. If not, you’ll want to move on to our list of solutions below.

How To Clear Out Kitchen Sink Drain

As previously mentioned, even if you suspect that there is no clog preventing your kitchen sink from draining, there most likely is. Whether the clog is exceptionally stubborn or simply hidden, there is a good chance that one of the following methods will fix the problem.

1. Use Boiling Water To Help Kitchen Sink Drain

Pouring boiling water down your kitchen sink is generally the first move to try to help it drain. Grease, soap residue, food scraps, and even hair can become trapped in your drain. Often, boiling water is all your pipes need to free the blockage.

If you haven’t already tried this method, simply bring a gallon of water to a boil and pour it directly into the drain opening. Then, turn on the faucet to check if drainage has improved.

If your kitchen sink still won’t drain, repeat the process. After the second attempt, if the boiling water is still unsuccessful at improving drainage, move on to another method. If you’ve arrived at this article, odds are that your sink clog is too stubborn for this method anyway.

Note: Do not attempt this method if your kitchen sink drain is connected to PVC pipes. Boiling water could damage or melt the plastic.

2. Check Your Garbage Disposal

If your kitchen sink has a garbage disposal, it may be the cause of your drainage issues and should be one of the first things you check. If there is a blockage in your garbage disposal, simply turning it on will usually break it up.

However, if the disposal has overheated or is malfunctioning and won’t turn on, you can reboot it by initiating the reset switch on the side of the base of the unit. After resetting your garbage disposal, switch it on again to see if this improves the drainage in your kitchen sink.

If you hear a low humming noise when you switch on your disposal, the device may be broken or jammed. Before you begin troubleshooting this issue, turn off the power to the disposal and NEVER stick your hand inside. At this point, you can attempt to free the drain by turning the blades manually with an Allen wrench.

If this doesn’t work, there is likely something stuck in the drain trap or piping connected to the disposal. In this case, you’ll need to disconnect the fittings on the drain trap, loosen the pipes manually, and use a bucket to catch any water or debris. Then, use a small scrub brush to dislodge any materials inside.

3. Plunge The Problem

If the above techniques did not work, a little bit of elbow grease may be necessary. If you have a garbage disposal, make sure that you unplug it before you even think about plunging. If you have a dishwasher, seal off the drain with a clamp to prevent any dirty water from back flowing into the appliance.

As far as plungers go, experts suggest that a flat-bottomed one is the best choice for the job. Once you have your plunger ready, follow these steps to free any possible clogs and improve drainage in your kitchen sink.

  • Fill your kitchen sink halfway with hot water so that it creates a seal around the drain.
  • Place the plunger over top of the drain and start quickly pumping up and down several times.
  • Remove the plunger and wait a moment to see if the water drains.
  • Repeat the above steps until the water drains appropriately.

If after several attempts the kitchen sink still won’t drain, you may need a more aggressive method.

4. Break Down Blockages With Baking Soda And Vinegar

Popular drain cleaners such as Drano or Liquid Plumr consist of corrosive chemicals that are also harmful to the environment. While they may boost effectiveness, it is best not to use them in your sink drains. Instead, try implementing natural at-home remedies to free blockages and allow your kitchen sink to drain appropriately.

An excellent alternative to commercial drain cleaners is two household items that can often be found around the home: baking soda and vinegar. To use this mixture, first remove any standing water from the sink using a cup or bowl. Then, proceed with the following steps:

  • Deposit one cup of baking soda into your kitchen sink drain. Use a spoon or spatula to press the powder down the drain, if necessary.
  • Follow this up by pouring one cup of white vinegar into the drain opening.
  • Cover the drain with a stopper to seal the opening.
  • Allow the vinegar and baking soda solution to sit for at least fifteen minutes.
  • After the time is up, remove the stopper and run hot tap water down the drain.

As with any other unclogging technique, this natural remedy isn’t always 100% successful. However, if you feel like you’ve made progress with the drainage, you can try repeating the process to increase its effects on the blockage.

5. Attack The Issue With A Plumber’s Snake

Especially stubborn clogs will necessitate the strength of a plumber’s snake (also called a drain auger) to help return proper drainage to your kitchen sink. This tool has a coiled spiral snake to reach deep down into the drain. When the snake hits an obstruction, cranking the handle will dislodge the debris and pull it out. For best results, use an electric snake as they have much more power.

If you don’t have a plumber’s snake on hand, you can improvise by making one out of a wire coat hanger. Simply unwind the hanger, using your hands or a pair of pliers, into one long piece of wire. Maintain the hooked end though, as this is what you will grab onto to free debris. Keep in mind that a coat hanger snake may not be as effective on tough blockages.

Regardless of the tool you are using, feed it into the drain a few feet at a time. Do not push too roughly, as you could accidentally push the clog further into the pipe. Once you feel the tool hit an obstruction, hook onto it, and pull it up the drain. Keep this process going until you feel that the drain is clear and run hot water to verify.

Pro Tip: Many homeowners whose kitchen sink wouldn’t drain and suspected that there was not a clog were able to fix the problem using a snake. In this case, rather than a solid object, the clog was more like a sludge. Try renting a snake with a motor and insert it no more than a foot into the pipe. This should allow you to tunnel a hole large enough to penetrate the sludge. Then, run hot water and a mild dish detergent to free the rest.

6. Clear Out The P-Trap

In most cases, a kitchen sink drain that won’t drain but “isn’t clogged,” has to do with the P-trap. This pipe is elbow-shaped, with a deep bend like the letter ‘P,’ and is located underneath your kitchen sink counter. The P-trap is designed to catch debris before it can clog the waste line. It keeps sewer smells from escaping into your home.

However, food, grease, and other debris may have become trapped inside the pipe, causing your sink to either drain slowly or not at all. The water simply hits a snag on the way down, preventing it from draining properly. To fix this problem, you need to disassemble the pipe and clean out the gunk inside.

Your P-trap can be easily removed by detaching the locknuts. Place a bucket or tray underneath the pipe to catch any water or debris that may escape. Remove the P-trap, inspect for gunk, debris, and residue, and clean it out. Then, reconnect the trap and turn the faucet on to verify that it drains.

7. Use Eco-Friendly Drain Cleaner

Corrosive substances like Drano used to be the go-to solution for clogged drains. Unfortunately, the usage of chemical-filled cleaners has plenty of downsides.

First, if a pet, child, or even yourself comes into contact with these cleaners, they can cause severe burns. Plus, they add chemicals to your water supply and are corrosive to your plumbing.

Overall, chemical-filled drain cleaners just aren’t worth it. And while vinegar and baking soda can break down some blockages, they aren’t always strong enough on their own.

An effective drain cleaning product that’s natural, safe, and environmentally friendly is a much better choice. There are plenty of options: Green Gobbler, ECOS Earth Enzymes, Earthworm Drain Cleaner, and Unique Super Digest-It, just to name a few.

8. Call A Plumber

If you’ve exhausted all the above methods and your kitchen sink still won’t drain, it’s time to seek the help of a certified professional. A licensed plumber can effectively diagnose and fix the problem at hand. They can also offer tips on how to avoid the problem in the future.

If you don’t already have a reliable go-to plumber to call, do a quick internet search for “plumbers near me.” If possible, check out reviews and feedback from others. This way, you can ensure that your chosen plumber has the skills and experience necessary to tackle the issue.

How to Prevent Future Kitchen Sink Clogs

Now that you’ve gotten your kitchen sink to drain properly again, you’ll want to ensure that you are taking the necessary measures to ensure that a clog never occurs again. The best preventative measure is to refrain from putting destructive items into your drain. These include:

  • Meat
  • Eggshells
  • Coffee grounds
  • Gum
  • Fruit peels, stickers, and pits
  • Grease, oils, and fat
  • Paint
  • Starchy foods, like rice, pasta bread, or quinoa
  • Paper products, including food wrappers and paper towels

Pouring cooking grease down the drain is a common mistake that many homeowners and renters make. Instead, dispose of grease in an old can or jar and then toss the container once it’s full. For items like coffee grounds, egg shells, and fruit peels and pits, you can add them to compost piles.

In addition to avoiding putting specific items down the drain, you should also refrain from overloading your garbage disposal. This can cause clogs as well. Try not to grind down more than a cup of food waste at any given time.

Pro Tip: Mix together equal parts water and vinegar, and freeze this mixture in an ice cube tray. About once a month, place a couple cubes in the disposal and grind them down to free up any food-waste buildup and keep things fresh.

Three Things To Avoid Pouring Down Your Drain

In reality, only water should be going down your drain. However, we know that other substances occasionally making their way down the drain is sometimes unavoidable. Still, there are three main things that you should make an effort to avoid pouring down your drain.

1. Oil And Grease

Have you ever left a pan with butter or bacon fat sitting out at room temperature? The congealed substance that results is less than appetizing, and your pipes don’t like it either. Instead of rinsing the pan and letting all the oil and grease go down the drain, dispose of it in the trash can.

Think of it this way: Every time you dump oil or grease into your sink, you’re adding a layer of gunk and buildup to your pipes. Even if you don’t have a problem with sink drainage now, you will eventually as the buildup continues to grow. It will inevitably become a clog that blocks water from flowing smoothly through the pipes.

2. Soaps And Chemicals

Soap on its own isn’t problematic; it’s when soap mixes with mineral-heavy water that it becomes an issue. This is because it becomes soap scum, which you’ve probably seen before in the shower. It’s a white, sticky substance that can build up and cause major clogs over time.

Chemicals, such as those found in corrosive cleaners, can also lead to buildup.

3. Scraps Of Food

We’ve all shrugged off the occasional noodle, crumb, or string of cheese that makes its way down the drain. But in reality, food scraps are some of the worst contributors to clogs in pipes. Even if you have a garbage disposal, it’s not wise to let chunks of food go down the drain. Not only will they eventually cause a clog, but they can lead to major pipe damage that is pricey to repair.

Do You Need to Hire a Plumber?

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Our Takeaway

When your sink isn’t draining but the pipes are clear, start by using boiling water to clear your pipes. Checking your garbage disposal, using a plunger, and breaking down blockages with vinegar and baking soda are all effective options as well. You can also utilize a plumber’s snake, clean out the P trap, and invest in an eco-friendly drain cleaner to help your sink drain properly. If all else fails, then it’s time to call in a professional plumber to diagnose and repair the issue.

Jessica Stone
Jessica Stone

Jessica considers herself a home improvement and design enthusiast. She grew up surrounded by constant home improvement projects and owes most of what she knows to helping her dad renovate her childhood home. Being a Los Angeles resident, Jessica spends a lot of her time looking for her next DIY project and sharing her love for home design.

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