No, it's not normal for your drain to smell like that, but it is easy to fix
Sinks, drains, and disposals—everything including the kitchen can stink to high heaven when not cleaned properly. The smell of musty, mucky mold or the inexplicable smell of sewer gas can all link back to a dirty drain. Thankfully, learning how to clean a smelly drain is a quick and easy DIY job you can finish before you even hop in the shower.
Perhaps the most important step in this guide occurs before you even start cleaning. Always begin by figuring out why your drain smells in the first place. While most smelly drains—particularly smelly bathroom drains—stem from a buildup of mold, mildew, or biofilm, the occasional culprit requires a plumber.
Here are the top reasons why your drain smells:
Buildup of hair, skin, and soap scum
Clogged, dry, or leaking P trap (the elbow-shaped drain at the base of your sink)
Clogged pipe, appliance drain tube, or garbage disposal
Small leak somewhere in your system
If you suspect the smell is coming from a major backup, don't move on to the steps below quite yet. First, try and clear an existing drain clog. While the steps are often similar to those below, tougher clogs may require a plunger, a drain snake, or the help of a pro. If you notice the common signs of a leak in your house, particularly around the smelly drain, then it's important to call a local plumber and let them handle the tough stuff.
All this being said, to deal with a smell drain thanks to stinky bacteria, mold, mildew, and that mysterious black gunk, read on.
Faint smells may not require more than a good flush of near-boiling water. Heat up 2 to 3 cups of water, but let it cool down a bit before sloshing it into the sink. While wearing rubber gloves, gently pour the water down the drain, keeping an eye out for any muck that breaks loose in the process.
If you suspect it’s a particularly dirty drain—and hold-your-nose levels of muck—move on to cleaning your drain with natural products. Sprinkle 1/4 cup of baking soda in and around the drain. Let it sit for up to 15 minutes.
Hot tip: Baking soda and vinegar are also a great way to clean your tub, so if you're cleaning a stinky tub or shower drain, take on both tasks at once.
White vinegar, apple cider vinegar, and lemon juice are all natural and relatively gentle solvents. Combining them with baking soda in a drain can break up mold, mildew, and biofilm. Pour a one-to-one solution of the solvent and water down the drain so it meets up with the baking soda.
While it may feel easier to reach for bleach, ammonia, or drain cleaner, it's often unnecessary. Also, it's always important to get to know the pH levels of your cleaning products, as some of them are corrosive and contain harmful fumes. Most importantly, never mix cleaning solutions, even with pantry products.
Let the baking soda and natural solvent sit in your drain for up to 15 minutes. Even after you enjoy the incredibly satisfying initial fizz, let the solution do its job before rinsing or scrubbing.
Use a soft sewer drain brush or pipe cleaner, preferably from the hardware store, to break up the remaining smelly muck around the rim of your drain opening. Be gentle while scrubbing—brute force with a metal brush can damage the lining of old pipes.
Do you have any of that warm water left over from earlier? Pour another 2 to 3 cups of water down the drain to rinse the final bits of muck away. Wait for several hours before testing and seeing if the smell returns. If so, move on to the next step.
As we mentioned earlier, the P trap is the curved pipe below your sink and shower drain that serves many purposes. For one, it saves a bit of water at its base to keep sewer gas from back flowing to your drain.
While the steps above offered a basic flush of your P trap, you could have a larger clog that requires manual removal. Place a bucket below your P trap and unscrew the two nuts on either side of it. You might need a pipe wrench or just your hands to loosen it. Once it's loose, visually inspect the inside of the P trap and rinse it with hot water and a natural solvent.
Are you still sniffing something funky? It may be time to call in a pro to investigate a larger cause. You may have a clog in your plumbing air vent or a deeper issue with your home's sewer main line.
Learning how to clean a smelly drain is one of those homeowner—and renter—must-have DIY skills. In fact, if your drains are prone to buildup, it's best to flush your drains once or twice a month to avoid smells and clogs.
But let's say you've let the drain get a bit too stinky, or you can't seem to get to the bottom of the issue. Call in a local drain cleaner to check your drain for a less-stinky solution. The cost of drain cleaning averages $220 for the visit, so you can save money by investigating the issue on your own first.
That pungent rotten egg smell coming from your drain is likely the buildup of biofilm—hair, skin, and soap scum that turns into a black sticky mess. In this case, pouring down near-boiling water, baking soda, and white vinegar will remove the smell. Keep in mind that a rotten egg smell is occasionally a sign of larger sewage line clogs and other related issues.
A plumber can get to the bottom of your smelly drain and clean it with specialized jets, hoses, and drain-safe cleaning solutions. It is also smart to call in a plumber if you suspect your drain smell is coming from a stubborn clog or even a leaky pipe.
Bleach—even diluted bleach—is not always the safest option for cleaning your drains. With a high pH, bleach can be highly corrosive to many types of pipes, especially when used regularly. When mixed with household cleaners and organic waste, it can also create dangerous chemicals. Remember to use proper protective equipment and ventilation when dealing with bleach.