Why does my kitchen sink drain keep smelling bad?
Persistent sink odors often stem from trapped water, incorrect pipe configurations, or buildup in multi-basin setups and overflow holes that standard disposal cleaners cannot reach. This trapped residue causes recurring foul smells that only temporarily disappear with bleach treatments, forcing people to constantly mask the issue rather than fixing the root cause.
What the numbers show
Counted from the threads quoted below. How we count
- People have been saying this in most months since September 2026.
- This comes up 13.9× more often in r/Plumbing than across the site as a whole.
What people tried
Every workaround mentioned in the threads below. We haven’t tested any of them — and nobody here is claiming they worked.
Found another way around this?
Share your steps and trade-offs so fellow engineers don't have to reinvent the wheel. No account required.
- 1pouring drain cleaner down the drain2 people mentionedDid this help you?
- 2using disposal cleanerDid this help you?
- 3realigning the plumbingDid this help you?
- 4changing the pipe layoutDid this help you?
- 5Bleaching the overflow holeDid this help you?
- 6replacing the dishwasher drain hoseDid this help you?
- 7cleaning the dishwasher and filterDid this help you?
- 8adding a high loopDid this help you?
- 9cleaning out the rubber piece in the disposal drainDid this help you?
- 10Look up s-traps and air admittance valvesDid this help you?
- 11Install an air gapDid this help you?
- 12Replace dishwasher discharge lineDid this help you?
- 13Create a high loop for dishwasher drain linesDid this help you?
- 14Treating the drain and garbage disposalDid this help you?
- 15Taking apart the aerator and cleaning it with vinegar and baking sodaDid this help you?
- 16Considering buying a new kitchen sink faucetDid this help you?
- 17Using specialized pump products that push cleaner up and out of the overflow, or attempting custom cleaning methods like pouring baking soda and vinegar directly into the overflow opening.Did this help you?
- 18Checking if the drain is slow, plugging the sink to see if it bubbles or gurgles, checking the p-trap for water, and cleaning gunk out of the overflow hole or pop-up assembly.Did this help you?
- 19tried some pads covering the bottomDid this help you?
- 20squirt bleach down the overflow channelDid this help you?
- 21remove and clean the drain plungerDid this help you?
- 22brushing teeth in the showerDid this help you?
- 23pouring water in the drains to fill the p-trapsDid this help you?
- 24opening the windowDid this help you?
- 25running water consistently in the bathroomDid this help you?
- 26maintenance replaced piping beneath the sink, resealed the toilet, and replaced kitchen sink pipingDid this help you?
- 27Pouring water or bleach down the drainDid this help you?
- 28Cleaning residue with anti-fungal solutionsDid this help you?
- 29Wrapping the drain area in plastic wrapDid this help you?
- 30pouring baking soda then vinegar down the drainDid this help you?
- 31taking apart and cleaning plumbing componentsDid this help you?
- 32pouring bleach through the sink overflow openingDid this help you?
- 33adjusting tailpipe extension and p-trap heightsDid this help you?
- 34trying simple drain cleaning solutionsDid this help you?
- 35inspecting the roof vent for clogsDid this help you?
- 36Hiring plumbers and drainage engineers to run camera inspections through the lines.Did this help you?
- 37Disconnecting waste hoses to check for odor sources manually.Did this help you?
- 38Cleaning out the plughole to temporarily mask the odorDid this help you?
- 39dumping five gallon buckets of water down the drainDid this help you?
- 40using baking soda, vinegar, and chemical drain cleanersDid this help you?
- 41running every faucet in the house for long periods of timeDid this help you?
- 42Removing and cleaning the trap under the sinkDid this help you?
- 43Having the pipes cleanedDid this help you?
In their words
Unedited, grouped by where they were said, most upvoted first within each place, each linked to the thread it came from.
“Has anyone dealt with a smelly faucet?”source ↗
“It’s only in the kitchen sink faucet, none of the other sinks or showers, so I don’t think it’s the water.”source ↗
“I’ve taken apart the aerator and cleaned it with vinegar and baking soda and that seemed to improve the smell for a couple days.”source ↗
“Ever since I changed the 3 faucets all 3 faucets have a sewer smell when they are turned on for the first few seconds but only after not being used for a minimum of 6-8 hours.”source ↗
“what I found was the drain tail piece that goes thru the sink has side openings that allow the sink overflow drain to drain, however in my case the tail piece allowed water to remain in the overflow drain and would develop a sewer type smell”source ↗
“Been dealing with this annoying foul odor coming from under sink ever since buying new house.”source ↗
“The smell is most concentrated under the sink but also sometimes leeches out from dishwasher.”source ↗
“The smell is driving me crazy”source ↗
“That brownish liquid sitting in the drain fitting is your clue, if there was a proper trap it would hold water to block sewer gas but if it dries out or was never installed right the smell creeps back.”source ↗
“The sink has 3 basins, and is almost always smelly even after disposal cleaner is used”source ↗
“Just wanted to check to see if the setup of the trap and drain could be the culprit”source ↗
“hello, looking for some help on a sour, ugly smell from under the kitchen sink of a pretty old home.”source ↗
“My kitchen sink frequently smells terrible, especially while the dishwasher is draining.”source ↗
“I’ve replaced the dishwasher drain hose three times, and the smell improves for a few weeks but always returns.”source ↗
“I’ve also cleaned the dishwasher and filter multiple times.”source ↗
“While running water at this bathroom sink I’m getting a sewage smell coming from the drain.”source ↗
“There’s a bunch of biofilm and sludge stuck to the walls of the pipe, the stopper and in the p trap. Running water disturbs it and aerosolizes the funk so you smell it.”source ↗
“I had my bathroom refurbished 6 months ago and I'm finding that the sink is getting very mouldy smelling.”source ↗
“I cleaned the plughole out a few weeks back but it's developing quite an unpleasant smell again.”source ↗
“There is a smell coming from our floor drain in the laundry room.”source ↗
“We have gone through a number of potential remedy’s over the years with temporary success. It keeps coming back.”source ↗
“The last couple days however, it’s been back and nothing will get rid of it for more than a couple hours.”source ↗
“I have this system and a strong smell has appeared.”source ↗
“I had the pipes cleaned, removed the trap, and cleaned it, but only the one under the sink.”source ↗
“It seems the smell only comes from the overflow hole. It is not really a sewage smell per se, but just not great. If I bleach it, it goes away for a week or so and then comes back.”source ↗
“I am at a point after lots of cleaning that I am convinced the issue is in the overflow... but I don't see any products to clean there.”source ↗
“Bathroom sink has a bad smell when running water, but the water itself doesn’t smell - what should I check?”source ↗
“Is this a standard set up? It’s giving off a musty odor. Maintenance cleaned off the residue with an anti fungal but the odor is back again.”source ↗
“I’ve lived here for almost 10 yrs and it just started smelling a few years ago.”source ↗
“one of the bathroom tubs stinks like septic.”source ↗
“I have tried every simple solution to no avail.”source ↗
“Intermittent rotten egg smell from kitchen sink.”source ↗
“We've already had two plumbers and two drainage engineers out to look at it.”source ↗
“The smell hits randomly.”source ↗
“Does this setup look like it's sucking the water seal dry?”source ↗
“There used to be a faint smell coming from there. It appeared about a month ago and has become really strong.”source ↗
“My husband and I live in the Caribbean - recently bought an old house- and noticed that when we are showering jt smells like a fishy smell.”source ↗
“One of the bathrooms has this odor at rest but the one we shower in I - notice it when the water is flowing over me (he says the same as well).”source ↗
“I can’t tell if it’s the water or the drain but it’s potent enough where my body smells like fish when I shower.”source ↗
“I have a bathroom sink in a condo that has been giving off a bad smell when the water is running.”source ↗
“I’ve had this from the drain plunger being full of hair and gunk.”source ↗
“there is a horrible sewage smell that routinely fills my entire house.”source ↗
“the smell first seemed to appear somewhere in the guest bathroom, but after a few fixes the smell has moved toward the kitchen (which shares a wall with the guest bathroom)”source ↗
“It is quite an awful sour smell that I just can’t seem to get rid of.”source ↗
“we’ve been running water consistently in the bathroom and the smell still remains”source ↗
Where this came up
People with this problem also raised
- 30Why does my sink drain keep clogging up?
- 2Why does my drain smell like sewage even when clean?
- 15Why is water backing up into the sink when appliances drain?
- 37Why does flushing one toilet pull water out of another?
- 6Why does my house smell bad after taking a shower?
- 4Why does my washing machine smell musty even with the door open?