Bathroom Sink Odor at Overflow Holes: Identifying and Eliminating

LESLIE: Now we’ve got Joyce in Alabama on the line who’s got a question about a sink odor. What’s going on?

JOYCE: Well, this is in a bathroom sink. It’s about 25 years old. It’s a type that has three air-vent holes, or overflow holes, in it. And the odor seems to be emanating primarily from there. It’s a very musty odor and came down to that conclusion because I finally took some paper and stuffed up those holes. And things smelled much better in the bathroom that way.

TOM: Well, sometimes what happens is you’ll get some bacteria that will grow in that overflow trap. So what I would suggest you do is eliminate it: that is to fill the sink up with hot water and add some bleach to it and let the bleach very slowly trickle over that overflow. And so it saturates it and hopefully that will kill that mold or that bacteria.

Now, the other thing that you can do is you could take the bathroom-sink trap apart and clean it out with a bottle brush. Now, some of the traps today are just plastic. They’re easy to unscrew and put back together. Under the sink, sometimes you can clean that. And again, you get that biogas that forms in there. If you clean it with a bleach solution, that usually makes things smell a lot better in the bathroom. OK, Joyce?

JOYCE: Alright. Thank you so much.