# What is this smell coming from my drains? **URL:** \ **Category:** Factual Questions\ **Created:** [September 10, 2023, 10:13pm UTC](https://boards.straightdope.com/t/what-is-this-smell-coming-from-my-drains/989900 "2023-09-10T22:13:48Z")\ **Posts on this page:** 17\ **Page:** 1
**Author:** ![X.L.Lent](https://avatars.discourse-cdn.com/v4/letter/x/a5b964/32.png) [@X.L.Lent](https://boards.straightdope.com/u/X.L.Lent)\ **Post date:** [September 10, 2023, 10:13pm UTC](https://boards.straightdope.com/t/what-is-this-smell-coming-from-my-drains/989900/1 "2023-09-10T22:13:48Z")
I have side by side sinks in my kitchen. When large amounts of water are draining out of one sink, a horrible sulfur like smell comes out of the drain for the other sink. What is causing this? Particles of rotting food? Is there a good way to stop this? Running hot water down the drain for several minutes seems to help but is there a better solution? ---
**Author:** ![wolfpup](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/wolfpup/32/10618_2.png) [@wolfpup](https://boards.straightdope.com/u/wolfpup)\ **Post date:** [September 10, 2023, 10:20pm UTC](https://boards.straightdope.com/t/what-is-this-smell-coming-from-my-drains/989900/2 "2023-09-10T22:20:31Z")
IANAP, but I’ve had very good success with the new generation of liquid drain cleaners in unclogging drains. The one I’ve used several times (Liquid Plumr) has a formulation specifically for kitchen drains, dissolving the kinds of foodstuffs most likely to be in there. I realize your problem isn’t a clog, but this stuff will likely dissolve anything stuck in there that is causing the smell. ---
**Author:** ![Chefguy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chefguy/32/138_2.png) [@Chefguy](https://boards.straightdope.com/u/Chefguy)\ **Post date:** [September 10, 2023, 10:35pm UTC](https://boards.straightdope.com/t/what-is-this-smell-coming-from-my-drains/989900/3 "2023-09-10T22:35:13Z")
Sewer gas smell may indicate a blockage downline. Maintenance had to come into our apartment and run a snake down the line. As **wolfpup** mentioned, you might try a drain cleaner first. Maybe do it twice. ---
**Author:** ![a6ka97](https://avatars.discourse-cdn.com/v4/letter/a/c2a13f/32.png) [@a6ka97](https://boards.straightdope.com/u/a6ka97)\ **Post date:** [September 10, 2023, 10:37pm UTC](https://boards.straightdope.com/t/what-is-this-smell-coming-from-my-drains/989900/4 "2023-09-10T22:37:47Z")
I would guess improper drain design or venting. If you have 2 P-traps (one for each bowl) the volume of water going down one side pulls the water out of the trap on the other side allowing sewer gas to escape. ---
**Author:** ![Mk\_VII](https://avatars.discourse-cdn.com/v4/letter/m/5f9b8f/32.png) [@Mk\_VII](https://boards.straightdope.com/u/Mk_VII)\ **Post date:** [September 11, 2023, 1:37pm UTC](https://boards.straightdope.com/t/what-is-this-smell-coming-from-my-drains/989900/5 "2023-09-11T13:37:52Z")
A properly draining sewer should not smell. If it does, something is wrong with it. ---
**Author:** ![ratatoskK](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/ratatoskk/32/2987_2.png) [@ratatoskK](https://boards.straightdope.com/u/ratatoskK)\ **Post date:** [September 11, 2023, 2:09pm UTC](https://boards.straightdope.com/t/what-is-this-smell-coming-from-my-drains/989900/6 "2023-09-11T14:09:26Z")
I bought a house that needed the kitchen to be gutted and redone. Among the problems to be fixed was the drain smelled like in the OP and the cause was that it was not vented. ---
**Author:** ![kayaker](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/kayaker/32/441_2.png) [@kayaker](https://boards.straightdope.com/u/kayaker)\ **Post date:** [September 11, 2023, 2:32pm UTC](https://boards.straightdope.com/t/what-is-this-smell-coming-from-my-drains/989900/7 "2023-09-11T14:32:51Z")
> [@a6ka97](#): > > I would guess improper drain design or venting. This is the answer. Have a plumber redo your drains under the sink. An AAV or Studor vent might help if you want to DIY. ---
**Author:** ![Snipe70e](https://avatars.discourse-cdn.com/v4/letter/s/51bf81/32.png) [@Snipe70e](https://boards.straightdope.com/u/Snipe70e)\ **Post date:** [September 12, 2023, 4:51am UTC](https://boards.straightdope.com/t/what-is-this-smell-coming-from-my-drains/989900/8 "2023-09-12T04:51:47Z")
Your problem sounds like improper venting. It is a rare time that I would ever use chemicals to clear a drain. If the chemical does not clear the plug you now have a pipe filled with chemicals that the plumber will have to deal with. Plus many chemicals over time will not only dissolve the crud in the pipes but also some of the pipe. I have seen too many has mat clean ups after someone dumped a drain cleaner down a drain. I learned this lesson in 1968 as a 3rd class midshipman on a maritime academy training ship. Drain cleaner was dumped down as water fountain drain. It did not work, and the pipes had to be taken apart to be mechanically cleaned. When taking the pipes apart the liquid in the pipes splashed in one of my classmates’ eyes. He went to see the Doc in sickbay, and I got to clean up the mess. 50+ years ago and I still will not use drain cleaners or work on any pipes with any drain cleaners in them. ---
**Author:** ![kayaker](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/kayaker/32/441_2.png) [@kayaker](https://boards.straightdope.com/u/kayaker)\ **Post date:** [September 12, 2023, 12:24pm UTC](https://boards.straightdope.com/t/what-is-this-smell-coming-from-my-drains/989900/9 "2023-09-12T12:24:30Z")
My dad was a plumber. He did new construction, but one thing he taught me was that a clogged drain should be snaked. Chemicals have no place in a drain. ---
**Author:** ![Bosda\_Di\_Chi\_of\_Tricor](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bosda_di_chi_of_tricor/32/16845_2.png) [@Bosda\_Di\_Chi\_of\_Tricor](https://boards.straightdope.com/u/Bosda_Di_Chi_of_Tricor)\ **Post date:** [September 12, 2023, 12:43pm UTC](https://boards.straightdope.com/t/what-is-this-smell-coming-from-my-drains/989900/10 "2023-09-12T12:43:14Z")
Wrong and bad. That stuff is a complete pain to the plumbers who will have to help with any _serious problem_ anyway. **Try this instead : pour two cups of dish-washing soap down the drain. Wait 40 minutes to an hour. Then, add a half-gallon of warn (NOT HOT) water to the toilet. Small amounts of plunger use may be needed. Works like gangbusters.** ---
**Author:** ![wolfpup](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/wolfpup/32/10618_2.png) [@wolfpup](https://boards.straightdope.com/u/wolfpup)\ **Post date:** [September 12, 2023, 3:28pm UTC](https://boards.straightdope.com/t/what-is-this-smell-coming-from-my-drains/989900/11 "2023-09-12T15:28:45Z")
> [@Bosda\_Di\_Chi\_of\_Tricor](#): > > Wrong and bad. > > That stuff is a complete pain to the plumbers who will have to help with any _serious problem_ anyway. > > Try this instead : pour two cups of dish-washing soap down the drain. Wait 40 minutes to an hour. Then, add a half-gallon of warn (NOT HOT) water to the toilet … You mention toilets, but the OP’s problem was with kitchen sink drains, and mine were with bathroom sinks. My understanding from the label on the liquid chemical uncloggers is that they should never be used in toilets. > [@kayaker](#): > > … a clogged drain should be snaked. Chemicals have no place in a drain. Can’t argue with a pro, and it’s probably based on some people using these chemical uncloggers inappropriately, when there’s some object stuck in the drain. In my case, the bathroom sinks have built-in stoppers that make it impossible to snake the drain unless you remove them, whose mechanisms are not easy to reach for someone like me who is older and not very agile, and furthermore which prevent much of anything from being able to drop in there. In fact, two of the sinks that have become blocked are in bathrooms where they aren’t ever used for anything except hand-washing; no one brushes their hair in there, for instance. My suspicion is that it may be related to scale buildup around the stopper mechanism, because this place has hard water. I am not a plumber and not knowledgeable about plumbing, so take my anecdotes for what they’re worth. All I can say is that several times these blockages appear to have been spontaneous, and the liquid chemical clears them out like a charm. ---
**Author:** ![kayaker](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/kayaker/32/441_2.png) [@kayaker](https://boards.straightdope.com/u/kayaker)\ **Post date:** [September 12, 2023, 3:37pm UTC](https://boards.straightdope.com/t/what-is-this-smell-coming-from-my-drains/989900/12 "2023-09-12T15:37:17Z")
> [@wolfpup](#): > > In fact, two of the sinks that have become blocked are in bathrooms where they aren’t ever used for anything except hand-washing; no one brushes their hair in there, for instance. My suspicion is that it may be related to scale buildup around the stopper mechanism, because this place has hard water. My gf has a very nice master bathroom with a two bowl sink. Every six months or so I pull her stoppers out (unscrewing the mechanism from the back of the tailpiece) then I use a plastic strip to pull out gunk. It’s just a plastic strip with grabbing teeth. Sold as a disposable, but I’ve used the same one for many years. ---
**Author:** ![wolfpup](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/wolfpup/32/10618_2.png) [@wolfpup](https://boards.straightdope.com/u/wolfpup)\ **Post date:** [September 12, 2023, 3:43pm UTC](https://boards.straightdope.com/t/what-is-this-smell-coming-from-my-drains/989900/13 "2023-09-12T15:43:57Z")
Sounds different than mine. To remove my stoppers, you have to crawl way into the vanity cabinet and fiddle with spring-loaded clips back there. Even worse is the pedestal sink in the downstairs powder room, where this gadgetry is directly behind the pedestal, and I don’t see how you can reach it unless you’re an accomplished contortionist employed by a circus. But I agree that pulling the stoppers and cleaning them out is the right way to do it. ---
**Author:** ![kayaker](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/kayaker/32/441_2.png) [@kayaker](https://boards.straightdope.com/u/kayaker)\ **Post date:** [September 12, 2023, 3:56pm UTC](https://boards.straightdope.com/t/what-is-this-smell-coming-from-my-drains/989900/14 "2023-09-12T15:56:45Z")
> [@wolfpup](#): > > you have to crawl way into the vanity cabinet and fiddle with spring-loaded clips back there. Yes, that’s the way most bathroom sinks work. I do not crawl in, I reach in and work the clips, but I’ve done this many times and know where everything is. As far as contortionism goes, lying on my back and using a basin wrench to remove/install a sink is the worst job I’ll tackle. ---
**Author:** ![Pleonast](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/pleonast/32/1183_2.png) [@Pleonast](https://boards.straightdope.com/u/Pleonast)\ **Post date:** [September 12, 2023, 4:08pm UTC](https://boards.straightdope.com/t/what-is-this-smell-coming-from-my-drains/989900/15 "2023-09-12T16:08:54Z")
> [@kayaker](#): > > I use a plastic strip to pull out gunk Yes, this! Search your favorite retailer for “plastic drain snake”. They’re easy to use and very effective for pulling out gunk from a trap. I don’t even need to remove the stoppers. I also use a standard toilet plunger on sinks and showers. (Seal the sink’s overflow drain with a wet washcloth.) ---
**Author:** ![Lucas\_Jackson](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lucas_jackson/32/303_2.png) [@Lucas\_Jackson](https://boards.straightdope.com/u/Lucas_Jackson)\ **Post date:** [September 12, 2023, 6:53pm UTC](https://boards.straightdope.com/t/what-is-this-smell-coming-from-my-drains/989900/16 "2023-09-12T18:53:13Z")
This works well: - **Baking Soda & Vinegar** Pour one cup of baking soda and then two cups of white vinegar down your drain and wait 10 minutes. Flush it away with hot water . ---
**Author:** ![EnolaStraight](https://avatars.discourse-cdn.com/v4/letter/e/41988e/32.png) [@EnolaStraight](https://boards.straightdope.com/u/EnolaStraight)\ **Post date:** [September 18, 2023, 12:35am UTC](https://boards.straightdope.com/t/what-is-this-smell-coming-from-my-drains/989900/17 "2023-09-18T00:35:10Z")
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