Smelly bathroom; could it be overflow drain marked CLEANOUT?

Discussion in 'Shower & Bathtub Forum & Blog' started by powtothemoon, Jan 30, 2021.

  1. powtothemoon

    powtothemoon New Member

    Joined:
    Jan 30, 2021
    Location:
    Seattle, WA
    We just bought a 13-year-old condo in the Seattle area. The bathrooms look to be renovated in the past couple years with relatively new fixturing. There is a big soaking tub in the master bath (one of the selling points of the condo for us). Its a big fiberglass bathtub with shower and faucet one end, and then the drain and overflow towards the middle length-wise. The overflow has the words CLEANOUT stamped on it.

    On the day we moved in, I took a long hot bath. Afterwards, I noticed the bathroom smelled...odd. My husband couldn't smell it and took a bath himself a couple hours later. That night, it was strong enough that he woke me up at 1am to tell me that he could smell it, too. We hadn't smelled it before we moved in and we had the place inspected beforehand, including running the water a bit, before we bought.

    It smells very musty, but strong. It doesn't smell like typical "musty basement" to me, but considerably worse. It doesn't smell overtly like poo, though.

    I had a plumber come in the next day to investigate, in part because I'm not familiar with the scent of sewer gas vs bad hot water heater (ours is as old as the condo) vs mold and thought he could at least differentiate, if not fix the problem. He said he couldn't smell anything at all, and then didn't do anything other than tell us to try some enzyme cleaners, leave the very strong smell of cigarettes in the condo, and charge us $100.

    Enzyme cleaners didn't work. We cleaned all the hair out of the drain (there was a lot). We did many rounds of baking soda + vinegar (4-5?) in the drain and one in the overflow. It seemed to help while we were doing it, but then the smell would come back soon as soon as we stop running water. It doesn't seem to get much better or worse if we run the bathroom fan. It does seem to get a little better if we plug the bathtub drain, but not always. Bathtub drains just fine with no glug-glug-glugs. Toilet in that bathroom doesn't "glug" either, as far as we can tell and seems to be seated absolutely rock solid.

    There is a second full bathroom that shares the wall with this one that doesn't smell. We also have sinks nearby (just outside the bathtub/toilet room) that don't have a problem. Kitchen sink, dishwasher and clothes washer: no problems.

    This has been going on a week. The only two things we know help the smell at this point are: actively running the water into the tub and opening the master bedroom window and airing the place out.

    My questions are:
    1) Is there a way to tell for sure that its sewer gas?

    2) Could the fact that the bathtub drain says CLEANOUT have anything to do with it? Does a cleanout go to a p-trap, or is it on the sewer side of the p-trap? I can't find diagrams online -- or even information about cleanouts also being overflow drains -- and am wondering if that may be the culprit? Any ideas on what I should do to figure that out?

    3) Any general troubleshooting tips?

    My next step is to try to concentrate the smell in the bathroom as much as possible (shut doors, open drain) and call in another plumber for a second opinion...


    NOTE: I am not sure if this is important or not, so I'll add it: the condo building is on a hill and contains 6 units; ours is one of two on the bottom/basement-ish floor. The back wall of our condo is (we think) dirt, while one side and front is exposed with big, beautiful windows. Essentially -- we're in a kind of more-exposed-than-usual walkout basement. The whole building is on a pretty big hill with wetlands below. The bathroom in question is in the far interior corner of the condo such that it shares one wall with the other walk-out-basement condo in the building, and one wall with the dirt.
     
  2. Reach4

    Reach4 Well-Known Member

    Joined:
    Sep 25, 2013
    Location:
    IL
    Is that cleanout below the rim of the tub? Is there an overflow, other than the place labeled cleanout?

    I would plug your suspect hole if practical. I would isolate suspects with cheap thin plastic drop cloths. Lift each, to see if the smell is stronger under that drop cloth.

    Is your building served by a city sewer?
     
  3. Sponsor

    Sponsor Paid Advertisement

     
  4. Terry

    Terry Administrator Staff Member

    Joined:
    Aug 17, 2004
    Occupation:
    Plumber
    Location:
    Bothell, Washington
    How about taping some plastic over both the drain and the overflow? Maybe use the blue tape that pulls off easily.
    The tub should have a trap to prevent sewer gas from coming up the drain and the overflow.

    You can also pick up a gas detector at a hardware store to check it that way.

    https://www.amazon.com/Techamor-Y201-Portable-Combustible-Detector/dp/B07BM1XWB8

    If sewer gas is coming up from the tub, then maybe they didn't install a p-trap for that.

    Reach4, in the Seattle area, any condo will be on sewer. Septic would be the same issue though.

    [​IMG]

    The overflow is part of the drain.
     
  5. powtothemoon

    powtothemoon New Member

    Joined:
    Jan 30, 2021
    Location:
    Seattle, WA
    Thanks for responding!

    Yes, cleanout is below the rim of the tub, where you would expect the overflow to be. Looks just like an overflow, but is marked "cleanout". There is no other overflow in this tub.

    I will try plugging it today to see if we can isolate it for sure.

    Yes -- served by city sewer.
     
  6. powtothemoon

    powtothemoon New Member

    Joined:
    Jan 30, 2021
    Location:
    Seattle, WA
    Thank you for the picture and the reply.

    I will pick up the tape/plastic today and try that. I didn't know those gas detectors existed, I will look for one of those, too. Thanks. Will report back!
     
  7. Reach4

    Reach4 Well-Known Member

    Joined:
    Sep 25, 2013
    Location:
    IL
    Most of the overflows that are not labeled are still the place to clean out.

    Maybe put one plastic drop cloth on the tub, another over the toilet and surrounding floor, and another across the lavatory and its cabinet.

    Some prior threads:
    https://terrylove.com/forums/index.php?threads/sewer-gas-smell-in-bathroom-is-a-mystery.72700/
    https://terrylove.com/forums/index.php?threads/abandoned-bathroom-smells-moldy.69017/
     
  8. powtothemoon

    powtothemoon New Member

    Joined:
    Jan 30, 2021
    Location:
    Seattle, WA
    Good to know about the overflow being a typical cleanout. I wondered if that might be the case but I didn't remember seeing it be marked like that before so wasn't sure.

    I like your idea of covering each fixture. Will do that.

    Thanks for the additional forum links -- I searched before posting but didn't find those ones.
     
  9. powtothemoon

    powtothemoon New Member

    Joined:
    Jan 30, 2021
    Location:
    Seattle, WA
    I wanted to give a minor update, even though we're still very much in the middle of the investigation. After a little bit of delay due to a bad cold/flu and waiting on a couple Amazon deliveries:

    - We picked up that Tachamor Y201 combustible gas detector, as suggested by Terry above. I couldn't detect anything with it, but my (far more patient) husband was able to set it such that it would go off near drain of the suspect bathtub...but just barely. It only lit up the first light, which I think puts it in the range of ~50ppm.

    But...every other drain (non-stinky) in the house also sets it off at the same level. Also, my husband (3/6) and the dog (2/6).

    Then we tested it on a bottle of scotch (4/6 lights), and then we tested the bottle of scotch on ourselves.

    Anyways: after the combustible gas detector results, we decided to be optimistic and put heavy plastic drop cloth over just the overflow and the tub drain. We'll air out the rooms tonight and see how it smells in the morning. If its clear, we're closer to the culprit. If it still smells, we'll add plastic drop cloth over all the fixtures + toilet and go from there.

    - We cleaned off our dirty vent fan and sniffed around that to see if that smelled at all like what we're smelling (thinking maybe it was mold in the vents?), and it smelled shockingly like fresh laundry.

    - Generally: we are still confused about how exactly to describe the smell. It doesn't smell like dead-rodent-in-the-walls that we're familiar with from our childhoods; it doesn't smell like 'outhouse'; it doesn't smell just regular-basement-musty. I am CERTAIN there are people experience in this stuff out there that could walk into this room and say, "oh, that definitely smells like X". Does anybody know one just south of Seattle and want to pass on their phone number? :) Interestingly, we have a HEPA filter running in our master bedroom next to the stinky bathroom, and it doesn't do anything for the smell.

    Personal aside: My Dad passed away suddenly 5 years ago and he would've known exactly what to do here. He built the house I grew up in and that my Mom still lives in. He was the "would know exactly what is/isn't sewer gas smell" type. I've been missing him since I first started looking into buying a condo and feeling a little sad/lost without him to call about this. He would've loved that he might be able to help me even though I'm a grown-up satellite engineer 2000 miles away (he was a machinist, so we had the typical engineer-vs-people-who-actually-do-and-know-things dynamic...but friendlier). Anyways, thanks for answering the call that he can't.
     
Similar Threads: Smelly bathroom
Forum Title Date
Shower & Bathtub Forum & Blog Smelly Shower Drain May 9, 2018
Shower & Bathtub Forum & Blog P Trap wrong place, smelly overflow Mar 29, 2018
Shower & Bathtub Forum & Blog Trying to fix smelly drain and dropped screw! Jul 18, 2007
Shower & Bathtub Forum & Blog smelly mud Dec 18, 2005
Shower & Bathtub Forum & Blog shower drain collects white smelly crust Aug 29, 2005

Share This Page