That vent fan issue is way more common than people think. I once got called to a place where the fan was just dumping all the moisture into the attic, and the insulation up there was basically a sponge. The pool smell stuck around no matter what they cleaned. Sometimes it’s not even about the caulk or the toilet seal—if there’s hidden water, that chlorine-y smell just lingers. I always check under the tub and around the baseboards for soft spots or discoloration. It’s wild how much can hide out of sight.
That’s a good point about hidden moisture. I had a similar issue after we upgraded to a “quiet” vent fan, but it turned out the installer never vented it outside—just into the crawlspace. The humidity made the whole area musty, and that chemical smell wouldn’t go away. I ended up pulling back some insulation and found mold starting to form. It’s easy to overlook, but I’d say checking where the fan actually vents is just as important as looking for leaks. Sometimes it’s not even a plumbing thing at all...
“I’d say checking where the fan actually vents is just as important as looking for leaks. Sometimes it’s not even a plumbing thing at all...”
That’s spot on—venting into a crawlspace is a recipe for trouble. I’ve seen a lot of “pool smell” issues in bathrooms where the vent fan dumps moist air somewhere it shouldn’t. But if you’re still getting that chlorine-like smell, I’d double-check for any slow leaks around the toilet or under the sink too. Sometimes it’s a combo of poor venting and a tiny leak feeding mold or bacteria. Have you checked the wax ring under your toilet lately? That’s a sneaky spot for odors.
I’ve actually run into this exact thing at my aunt’s house. She kept complaining her bathroom smelled like a YMCA locker room, and she was convinced it was the water. Turned out, her fan was venting straight into the attic, and all that steamy air just sat up there making everything musty. But here’s the kicker—she also had a tiny drip under the sink that nobody noticed until we pulled everything apart. The combo of dampness and bad airflow made the whole place reek.
I’d second checking the wax ring, but I’d also poke around for any spots where water might be pooling—sometimes it’s not even a full-on leak, just condensation from pipes or even a loose supply line nut. I once found a “mystery smell” that ended up being a slow drip behind the toilet tank, soaking into the drywall. Took forever to track down because it never actually made a puddle.
One thing I learned: don’t underestimate how much stink can come from a little bit of moisture in the wrong spot. And yeah, if your fan isn’t venting outside, you’re basically marinating your house in bathroom soup... not ideal.
If you’ve checked all that and still get that pool smell, maybe peek at your cleaning products too? Some of those “fresh” scented cleaners are weirdly close to chlorine. My cousin swears by this blue stuff that makes her bathroom smell like a public pool for days.
Anyway, hope you find the culprit before you start handing out swim caps to guests...
That “bathroom soup” line cracked me up, but it’s so true. I’m paranoid about leaks now after finding a tiny drip under my sink that turned into a moldy mess. I’d never have guessed a little moisture could cause so much trouble. I also learned the hard way that some of those “ocean breeze” cleaners just make things smell more chemical-y, not cleaner. Now I stick to basics and double-check for drips every time I clean.