my least favorite question: what's that smell

February 1, 2024 6:00 AM

I have a gross question about household odors and why I may be encountering a persistent one.

Originally, I messed up by not knowing you are supposed to empty and clean an indoor dryer vent lint trap instead of just pouring in more water. The resulting mess was absolutely foul. It produced an odor I have only ever smelled in two other places: 1) bad breath, especially from unwashed dentures, and 2) some brands of denim jeans when they're new.

Naturally I bleached the trap when I cleaned it, so as to kill this bacteria. That did the trick to start with. Now I clean the trap every week. But I also catch a few notes of the bad smell every so often. I can't put my finger on it and it drives me nuts. Are you familiar with this situation? What did you do?

All I know is that I have a stack washer/dryer which was new when I moved in -- it's a rental, I didn't choose it. The trap looks just like this, although it may be a different brand. I do use washing machine cleaning powder once a week.

posted by anonymous to Home & Garden (12 answers total)

have you considered spending $20 to change the trap and tubing altogether with the item you linked?
posted by noloveforned at 6:04 AM on February 1 [4 favorites]

Investigate if there's a drain in the floor underneath the washer/dryer whose trap might have gone dry.
posted by mhoye at 6:41 AM on February 1 [5 favorites]

I wonder if the smell could actually be coming up from a dry drain. All drains are built with a loop called a P-trap inside that's meant to hold water so it forms a physical barrier against the smell of sewer gas. It looks like this. If the water in the p-trap evaporates, or gets sloshed out by forceful water going down the drain, there will be no barrier in the drain so the sewer gas smell can come up.

The fix is easy and free and worth trying - Anywhere you have a drain - including sinks, showers, basement entryways, the floor of your utility room, garage, etc, gently pour down a pitcher of tap water, to refill the p-trap. Do that every month or so.

You might have a drain under the machine, or if there was ever a laundry sink that they removed to install the stacking machines, there might have been a standpipe that didn't get capped. That could be the source of the smell. The article I linked above has lots of diagrams of the possible sources of the smell.
posted by nouvelle-personne at 6:46 AM on February 1 [4 favorites]

Thirding the possibility of a trap under the washing machine. Ass smell would periodically waft through our house for months before I finally figured out the problem.
posted by saladin at 6:48 AM on February 1 [4 favorites]

"'Originally, I messed up by not knowing you are supposed to empty and clean an indoor dryer vent lint trap instead of just pouring in more water."

You're pouring water into the lint trap?
posted by jonathanhughes at 7:26 AM on February 1 [25 favorites]

@johnathanhughes OP is not referring to the lint trap on the machine; they are referring to an external device like the one linked in the question, which is designed for venting the dryer exhaust indoors, which you do need to pour water into.
posted by mekily at 7:53 AM on February 1 [1 favorite]

omg the drain under the washing machine!! Our basement reeked for WEEKS before I figured out what it was. Anyway, nthing that suggestion
posted by goodbyewaffles at 7:56 AM on February 1 [2 favorites]

If your laundry is close to the kitchen, the refrigerator may be the culprit. There's a drip pan under there that my housemate and I discovered to our equal parts horror and relief. This was in the early 90s, but the memory of the smell remains powerful.
posted by Don Pepino at 7:56 AM on February 1

Is there a natural gas fitting or gas appliance nearby? I would check that as a possible source of the smell.
posted by zippy at 12:04 PM on February 1

There's probably crusty lint buildup in the tube that still stinks. I would replace the entire tubing situation like noloveforned suggested.
posted by oneirodynia at 12:26 PM on February 1

I agree it's most likely a dry floor drain where the water in the trap has evaporated. There is probably a grate in the floor somewhere - just pour a bucket of water down there and see if the smell goes away.
posted by dg at 5:35 PM on February 1

Do you have STEAM in your washer? I do and the hose stinks all summer because I don't use it. The solution is to run the washer with the steam setting 3 times. I have to do this weekly during the summer.
posted by andreap at 9:32 AM on February 3