Water Going Down Kitchen Sink Drain
© hues / Fotolia

A foul smelling drain can really ruin the ambiance of your kitchen or bathroom. Even worse, those funny smells generally mean there’s a buildup of debris that will eventually clog the drain and leave the sink unusable until you clear out the plumbing. Other possible causes for drain odors include plumbing issues that should be addressed as soon as possible.

Most smelly drains aren’t difficult to clean and taking care of the problem now will give you a more enjoyable home and prevent future plumbing problems.

Clear Out Grimy Drains

Bottle of Dishwashing Detergent
© genjok / Fotolia

If your drain is both smelly and running slowly, start cleaning it up by getting rid of the grime that’s built up inside. While baking soda and vinegar are often recommended for cleaning drains, in reality, this combination does little to break up the fats that are the most common cause of clogs.

For a more effective and equally simple way to clean the drain, use dishwashing liquid and hot water. Choose a dishwashing liquid designed to break up grease, such as Dawn, Ivory or Palmolive. Bring a pan or kettle of water to a boil, then turn off the heat.

Pour 2 or 3 tablespoons of dishwashing liquid into the drain, then slowly pour in the hot water. Wait 15 minutes, then prepare another pan of boiling hot water. Pour the water down the drain to flush away the loosened debris.

For stubborn buildup that won’t wash away with soap and water, try an enzymatic drain cleaner such as CitraDrain Natural Build-Up Remover, Earth Enzymes Drain Opener or Bio-clean Drain Septic Bacteria. The enzymes in these drain cleaners naturally break down clog-causing debris without harming your pipes or the environment.

Enzymatic cleaners won’t work on completely blocked drains, though. To get rid of a smelly blockage, you may need to use a tool such as a plunger or a plumber’s auger (drain snake) to break through the clog.

When possible, also clean the drain’s P-trap, the P-shaped section of pipe under the drain designed to catch debris before it travels farther into the plumbing system and causes a clog there. Place a bucket under the drain, unscrew the P-trap and dump the contents into the bucket. Scrub out the inside of the P-trap with a bottle brush or other tool

Avoid harsh, acidic drain cleaning chemicals, which can damage PVC pipes and pollute the water supply. If you can’t clear the blockage with basic plumbing tools, call a plumber.

A grimy garbage disposal is another potential source of drain odors. Odors can develop if you haven’t cleaned or used your garbage disposal in a while.

All you need to get it clean and fresh-smelling again is ice and a lemon. Prepare two cups of ice cubes and cut a lemon into quarters. Turn on the disposal and pour in a cup of ice while running the cold water. As the disposal is working on the ice, feed in two sections of lemon one at a time.

Repeat the process with the remaining ice and lemon sections. This process removes both built up debris and odors.

To keep odors from forming in the first place, always run the water for 20 seconds after you use the garbage disposal to ensure all the chopped up food waste is washed down the drain.

Once the drain is clean, the bad smells should go away on their own. To clear the air faster, deodorize the drain by slowly pouring 1/2 cup of baking soda down the drain while running the warm water. If you keep a box of baking soda in your refrigerator to absorb food odors, when you change the box, use the old baking soda to deodorize your drains.

Get to the Root of Odor-Causing Plumbing Problems

Plumber Working in Kitchen
© Petrik / Fotolia

Not all smelly drains are suffering from a buildup of debris. If you notice a sewer odor emerging from one or more drains, the problem isn’t a drain clog, but rather another issue with your plumbing system.

One possibility is a dry p-trap. Part of the p-trap’s job is to block odors from your sewage system so they can’t rise up the drain. In order to work, the p-trap must be filled with water.

When a drain isn’t used for some time, the p-trap dries out and can no longer block odors. The solution is simple: run the faucet for around 10 or 15 seconds or pour a bucket of water down the drain to refill the p-trap.

If all your drains smell unpleasant, a blocked vent pipe could be to blame. Your vent pipe carries sewer gases up to the roof to be released outdoors. Because the vent pipe has an opening on the roof, it can become clogged with leaves, animal nests, or snow.

When this happens, the sewer gases are pushed back down so that they back up into your sink drains. A blocked vent pipe will also cause your drains to run slowly.

You can clean a blocked vent pipe by taking a garden hose up onto the roof and spraying a strong blast of water into the drain. If you’re not comfortable doing this yourself, call a plumber for help.

Another potential cause of odors coming from every drain in the house is a leak or blockage in the sewer line that carries wastewater from your house out to the city sewer system. In this case, you’ll also notice gurgling and frequent clogs in the drains on the ground floor.

A leaking or blocked sewer line can cause serious damage to your home if not corrected quickly and this isn’t a problem you can solve yourself. If you suspect something is wrong with your sewer line, call a plumber.

Keep Your Drains Smelling Fresh

Kitchen Sink Drain Strainer
© Joe Gough / Fotolia

To prevent future odor issues, be careful about what you wash down the drain. Never pour in cooking oil, melted butter or other fats. These quickly solidify in the drain, where they stick around and trap other debris, which eventually starts to smell.

Sticky foods such as rice and pasta and gritty food waste such as coffee grounds and eggshells also shouldn’t go down the drain.

Use drain strainers to catch food particles, soap scum, hair, and other debris before it enters your drains. Once every week or two, clean your drains with dishwashing liquid and hot water to prevent debris from building up.

A smelly drain is a real annoyance, but the problem is often easy to solve yourself with common cleaners and tools you can find in any supermarket or home improvement store. When a DIY solution won’t help, a plumber can usually get your smelly drain problem solved fast.

Editorial Contributors
Henry Parker

Henry Parker

Henry Parker is a home improvement enthusiast who loves to share his passion and expertise with others. He writes on a variety of topics, such as painting, flooring, windows, and lawn care, to help homeowners make informed decisions and achieve their desired results. Henry strives to write high quality guides and reviews that are easy to understand and practical to follow. Whether you are looking for the best electric riding lawn mower, the easiest way to remove paint from flooring, or the signs of a bad tile job, Henry has you covered with his insightful and honest articles. Henry lives in Florida with his wife and two kids, and enjoys spending his free time on DIY projects around the house. You can find some of his work on Today’s Homeowner, where he is a regular contributor.

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