Fast Plumbing Answers: Why Does My Sink Drain Smell?

You walk into your bathroom or kitchen and are immediately hit with a nasty odor. A foul, persistent stink coming from your sink drain. Is it just a temporary issue, or a sign of a deeper problem? You need to know why your sink drain smells — and how to make it go away.

Don't worry — we'll answer all your questions in 2 minutes or less.

We’re Mother, a Dallas-Fort Worth plumbing company that provides dependable, hassle-free modern plumbing for homeowners who value quality. Call us if you need fast, expert drain cleaning service anywhere in the DFW Metroplex.

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The Fast Answer: Here's Why Your Sink Drain Smells

The most common reason for a persistent, foul odor from your sink drain is the presence of a corrugated drain. These flexible, ribbed pipes trap debris, soap scum, and other organic matter in their ridges. As this trapped material decomposes, it releases the foul, stinky smell you're experiencing.

Expert plumbers don’t install corrugated drain pipes. They’re flimsy and offer an easy landing place for bacteria and organic material. 

Other common reasons for a foul odor in your sink

• Dry P-trap: The P-trap is the U-shaped pipe under your sink. It’s designed to hold a small amount of water. This water acts as a seal, preventing sewer gases from entering your home. If the P-trap dries out due to infrequent use or an issue with the trap itself, sewer gases escape and cause a foul odor.
• Broken Sewer Vent: Your home's plumbing system includes sewer vents that extend through the roof. These vents allow gases to escape safely and help water drain properly. If one of these vents breaks, sewer gases enter your walls and permeate your living space.

That Bad Odor Isn't Your Biggest Problem

Yes, that smell is awful. It affects your personal comfort and quality of life. But a stinky sink drain also indicates an underlying plumbing issue. 

Ignoring these odors leads to more significant problems for your Dallas-Fort Worth main drain and sewer line down the road.

Potential problem #1: exposure to bacteria

Decomposing matter in corrugated drains creates a breeding ground for bacteria and other microorganisms. This produces a foul odor — but more importantly, it exposes your family to a host of bacteria.

Potential problem #2: sewer gas leaks

If the smell is due to a dry P-trap or a broken sewer vent, you are being exposed to sewer gas, primarily methane. 

Our plumber Dillon Ashton explains that sewer gas “needs to exit above the house so it's not hazardous to anybody in the home." Anywhere else, it becomes a health hazard.

Prolonged exposure to methane in sewer gas causes headaches, nausea, and other health issues. It also indicates a breach in your plumbing system that allows other harmful substances to enter your home.

Potential problem #3: poor drainage and slow drains

The same issues that cause odors — blockages in corrugated pipes — also impedes proper drainage. When your sink drains slowly, it creates standing water and contributes to unsanitary conditions.

Your Sink Drain Smells: Here's What to Do About It

Let’s address the underlying problems causing your smelly sink drains. We’ll eliminate that foul odor and prevent future drain and sewer line problems.

If you have a corrugated drain pipe

How to fix it: The best solution is to replace the corrugated drain with a proper, smooth P-trap and drain assembly. 

"We have a lot of handymen out there that ends up putting what's called a corrugated drain under our sinks,” Dillon explains. “To replace that, we either install a new proper P-trap or drain assembly to it so we can make that where it doesn't smell anymore." 

This project requires specific plumbing knowledge and tools to ensure a proper, leak-free seal. Hire a plumber for this — if you live in Dallas-Fort Worth, give us a call.

If you have a dry p-trap

How to fix it: If a P-trap has dried out due to infrequent use, simply run water down the drain for a minute or two. This will refill the trap and re-establish the water seal. 

If the P-trap is consistently drying out with regular use, Dillon says "there is a chance that the P-trap could have a crack or a drain issue.”

In this case, you need a plumber to inspect and potentially replace the P-trap.

If you have a broken sewer vent

How to fix it: A broken sewer vent requires professional plumbing attention. This issue is not a DIY fix, as it involves accessing and repairing pipes within your walls or roof. 

Our plumbers locate and repair the broken vent quickly and efficiently, ensuring proper gas ventilation and preventing sewer odors from entering your home.

Tired of Your Stinky Sink Drains? Call Mother

A smelly sink drain is more than just a nuisance. It's a sign that something is wrong with your home's plumbing. 

Whether it's a faulty corrugated drain, a dry P-trap, or a broken sewer vent, these issues require professional attention to ensure your home is safe, sanitary, and odor-free. 

Don't let a stinky drain linger in your Dallas-Fort Worth home. If you're experiencing foul odors from your sink drains, call Mother Modern Plumbing today for fast, expert diagnosis and resolution.

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