Most odors in sink or tub drains aren’t caused by sewer gas, since water in the drain trap acts as a barrier to prevent sewer gas from coming up into your home. Instead, the usual culprit is bacteria growing in organic matter—such as hair—which becomes lodged in the drain.
To remove organic matter and odors from a drain:
- Insert a drain cleaning tool in the drain.
- Pull the tool back out and remove any hair or other organic matter.
- Repeat until the drain is clear.
- Pour diluted bleach or hydrogen peroxide down the drain (one or the other, don’t mix the two together) to kill any remaining bacteria.
Watch this video to find out how.
Further Information
- How to Clean Out a Tub Drain (video)
- How to Unclog a Tub Drain (video)
- How to Unclog a Slow Draining Bathtub
VIDEO TRANSCRIPT
Allen Lyle: Isolated odors are not uncommon. We get the question all the time, “I’ve got this smell coming from just one sink “or just one tub. What is it?” Biggest fear is that it’s sewer gas. And it’s possible, but it’s not probable. Here’s why.
Under all plumbing, whether it’s an old house like this or a brand new one, you’ve got what’s called the P-trap. What happens, as water drains out of the sink or out of the bath tub, a small amount of water stays right in there, and that becomes a barrier to all of that sewer gas.
So, if you’ve got a crack in that pipe or a leak fix it, that’s probably all it will be. But more than likely, it’s the bacteria. Think about it, washing your hair, shaving, you get a lot of organic matter down a sink, and down a bath tub drain—this is really notorious here.
As you get the clog, bacteria begins to grow. What you need to do is just remove the clog. Easy to do, I’ve got a little zip tool here. We’ll slip that inside.
Once you remove the clog, you want to take a little diluted bleach, maybe some hydrogen peroxide, pour it down the drain—don’t forget about the overflow. That’s going to kill both the bacteria and the odor.
I have been fighting an odor coming from our shower drain for quite a while now using several different odor killing products, but with out any results. I just saw your video and am going to try it using hydrogen peroxide. You said in your video to use diluted bleach or hydrogen peroxide. Does the hydrogen peroxide need to be diluted also and if so what is the dilute rate?
Thank you
John Green
Hi, John, if you use hydrogen peroxide, no need to dilute it. Best of luck!
At what ratio do you dilute bleach and hydrogen peroxide to pour down bathtub drain.Thanks Mike
Mike, the ratio for bleach is 1:30, which equates to about a 1/2 cup of bleach to 1 gallon of water. No need to dilute household 3% hydrogen peroxide, as it’s already diluted.
Ordor from shower drain.. sometimes gone for weeks .. then back for weeks .. very strong
sewer smell enough to to go bedroom area
I tried peroxide .. seemed to work a little.. Bathroom high point of drain is tub . then two
vanity sinks .. shower and toilet.. then drain.. But smell is from drain in shower
I have a bad and STRONG mildew odor coming from the tub drain, stuck a 30 foot snake down there, couldn’t find a clog and the tub drains fine. The odor is so strong it makes your nose and eyes irritated and spreads into the other rooms when the door is open. What could this be and how do I get rid of it???
Dave
Hi, Dave,
Wet and Forget has some useful information on these odors.
Check out this article, http://www.askwetandforget.com/4-reasons-you-cant-afford-to-ignore-that-musty-odor-in-your-home/, and let us know if it improves!
Thanks for your question.
cliftonb1@verizon.net
There is a horrible odor that comes from our master bathroom tub. The house is about 10 years old and was new when we moved into it The tub is a jetted tub was never used, we shower. We live in VA and have a septic tank. Our plumber tells us to half fill the tub with water and let it drain out. It does go away for a while (sometimes a little while, sometimes a year). What could be causing this? Thanks
Ps. I should say a lot more rarely the laundry room sink has the same problem.
I have been in a my home that was built eight months ago. In the kids bathroom there’s a bad odor that comes when you flush the toilet. And somethings it brings in the sink drain that smell bad.
This happens only in cold weather. You can retire at night and when you get up in the morning our bathtub is solid brown. This happens when the warm and cold air meets. It doesn’t happen in the summer. We have been living in the house for 37 years and it was built in the fifty’s.
I have a septic, the summer is the worse, but i also have mold in the house, the smell is awful, i keep the sink drains closed and lids of toilets closed. to help. i use ridx more than once a month. but something other than that is making me ill in my home, i know i have mold in my home i clean it, i have holes in my floor, wher the floor is rotting and i need to fix, i have been told there is a underground spring running thru the property, neighbor has same problem with floors. but when i am in my home, which is a moble home, i am dizzy, headake, sleepy very sleepy, tired alot. and sometimes, like i am wacky. its weird. when i am gone from it i am fine. but within thirty minutes of entering back to the same. my daughter came by and same. no one wants to visit long. what could be causing the problem. i also have mice. and a dog that chases them. i have been dianosed with ecoli, and rashes, headakes, anxiety. nosebleeds. what can i do. help please help
Hi, Janet,
Thanks for sharing your experience. It sounds like quite a predicament, and we recommend submitting questions involving unique situations like yours to the Today’s Homeowner Radio Show.
Please use this form to contact Danny Lipford, America’s Home Expert, directly: https://www.todayshomeowner.com/radio/ask-questions/
Take care!
Your web page has provided me a lot of valuable advice, and for that I thank you so much.
This article is one of the best I’ve read until now on your
site, so I thought I needed to take some time to comment.
You’ve given me a number of tips to help me in the foreseeable future.