5 Signs You Should Clean Your Drains

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Clogged drains aren't just an inconvenience; they're a potential health hazard. It's essential to know when it's time for drain cleaning.

Two 18th-century inventions made it possible for every household to have clean, sanitary plumbing, and you probably won’t guess what they are. Yes, toilets and pressurized water systems were perfected around that time. But we’re talking about P-traps and drain venting, which really revolutionized plumbing.

As important as they are to a functioning plumbing system, they’re also responsible for many of the clogs homeowners face today.

A P-trap holds a pool of water that blocks sewer gases from entering the home, while the inverted “P” is a magnet for food waste, grease, hair and soap. The vents allow air into the pipes to equalize pressure. When one of them gets blocked, suction prevents water from flowing. The result looks like a drain clog but actually isn’t.

Of course, clogs can occur in other parts of the drain/waste/vent system for other reasons. Tree roots can grow in sewer pipes, and septic backups occur when tanks fill with sludge or drain fields become waterlogged. Whatever the cause, drain clogs produce telltale symptoms that are a call to action for vigilant homeowners.

What’s So Bad About Clogged Drains?

Though a partially clogged drain doesn’t render a fixture unusable, it can be a sanitation nightmare. Clogs are lumps of organic matter that attract insects and vermin and promote mold and bacteria growth. They can be responsible for leaks, unpleasant odors, contaminated water and health problems. In a worst-case scenario, they can cause structural damage to your home.

Clogs aren’t always immediately apparent. If water still flows, you might not be aware of the health hazard lurking in the pipes. That’s why it’s important to watch for telltale signs. Some are easy to identify as drain-related and some aren’t. Here are some of the most common indications your drains need cleaning.

Standing Water

Whether it’s in a sink, bathtub, shower or on the basement floor, standing water indicates a complete drain clog. When you see it in a plumbing fixture drain, the clog is most often in the P-trap, but it could also be deeper in the pipes.

Usually this type of clog can be cleared with a plunger or a snake. If the P-trap is accessible, it’s often best to disassemble it and actually clean it out.

Standing water in the basement often points to a clog in the sewer, especially if it’s a recurring problem. You may need a plumber to diagnose the problem, which could be tree roots growing in the pipes or a frozen pipe.

When a floor drain suddenly backs up for the first time, it’s not as serious as a recurring clog. Removing the drain cover and plunging or snaking the drain usually does the trick.

Note: Caustic chemical drain cleaners seldom help with standing water. Moreover, they generate heat that can damage pipes, burn skin and create toxic vapors, so they are best avoided.

Unsavory Odors

If you can’t pinpoint the source of a musty or unpleasant odor, it could be coming from a drain. Stinky clogs tend to be close to the drain opening because if they’re deeper in the pipes, the water in the P-trap blocks the odor.

Use a Zip-It tool to pull gunk-collecting hair out the drain. Scrub thoroughly around the drain opening, then deodorize the drain by pouring in half a cup of baking soda followed by a half cup of vinegar. The resulting fizz will do the rest.

Bugs Around the Drain

Wherever there are bugs such as fruit flies, drain flies or cockroaches around a drain, there’s something in the drain attracting them. The baking soda/vinegar regime accompanied by a thorough scrubbing of the drain opening usually clears up the attractants. But if you see bugs often, be more careful about what you’re putting in the drain.

When bugs congregate around a garbage disposal drain, clear the food particles from the rubber splash guard. Grind up one or two sliced lemons or oranges, peel and all. Then do the baking soda/vinegar treatment.

Drain Gurgles While Draining

A partial clog in a sink, tub or shower drain can restrict water flow just enough to trap air, which bubbles up out of the drain and creates the gurgling sound. This is a good opportunity to use an enzyme-based drain cleaner. Follow the instructions on the container and stop using the drain for several hours to give it time to work.

Drain Gurgles When You Flush the Toilet

Gurgling sounds from a sink, tub or shower drain every time you flush the toilet could come from a partial clog or indicate a blocked vent.

To eliminate the possibility of a clog, cover all the drains in the bathroom with duct tape, then plunge the toilet. Taping the drains prevents the force you create with the plunger from dissipating and directs it squarely at the clog. If the gurgling persists, look for a blocked vent.

Remember Those Vents We Mentioned?

Besides a drain clog, there’s another reason why drains smell — a blocked plumbing vent. Without the air the vent lets in, suction created by running water can pull water out of the P-trap, allowing sewer gases to pass through the trap and out of the drain opening.

When this happens, it’s usually because the vent opening on the roof is blocked with debris, which can only be cleared by climbing on the roof. In winter, ice could be blocking the vent. Because walking on a snowy roof is dangerous, go in the attic, find the vent pipe and warm it with a hair dryer to melt the ice.

Chris Deziel
Chris Deziel has been active in the building trades for more than 30 years. He helped build a small city in the Oregon desert from the ground up and helped establish two landscaping companies. He has worked as a carpenter, plumber and furniture refinisher. Deziel has been writing DIY articles since 2010 and has worked as an online consultant, most recently with Home Depot's Pro Referral service. His work has been published on Landlordology, Apartments.com and Hunker. Deziel has also published science content and is an avid musician.