View Full Version : Bathtub Drain Smell

07-05-2007, 07:59 AM
I searched the forums and no other thread regarding sewer gas smell in bathrooms fit my problem.

Our house is an old home, over 50 years old. Just recently (one other time) we smelled a horrid smell coming from the bathroom. I thought my fiance had just used the toliet :eek: , but no......it was not him. So we started to search for the source of the smell. Our bathroom is pretty small so it did not take long to find that the smell was coming from our bathtub drain. We figured it was gunked up, and that was what was causing the smell. Another odd detail is that whatever the odor was coming from the drain, had produced a stain above the drain on the bathtub wall. It was impossible to scrub off. We poured some drain de-clogger down there (made esp for hair) and then flushed the drain for a good 5 min. Smell still there, but not as bad. The next day it was completely gone. And that stain I could not get off? That was gone too!!!!

Now, a month later the smell came back. The stain is back too. Since this is only the 2nd time I have smelled the odor, I have realized that the first time the odor was there, it was SUPER hot & humid outside. We ran our window a/c ALL day. The smell was noticed at night. Same exact thing the 2nd time the smell came back. So it seems to be related to really hot & humid days as well as running the a/c unit all day. What could be causing this? We have lived in the house for almost 4 years and have smelled it twice now. We replaced the toliet right after moving in. For some reason the after replacing the toliet, the toliet was not bolted down tight enough which then caused leaking. After we noticed that, we tightened it and it has been fine. I am wondering if the smell from the tub has anything to do with that?

Please HELP!!!!!

07-05-2007, 08:08 AM
In my bathroom, the smell comes from the sink !!! BUT, the drain works fine. It smells when water is run down it. It does the same thing in the basement laundry tubs. I, too, would like some input as to the possible problem and solution - thanks

07-05-2007, 08:13 AM
Ours stinks without even running water down it!!! We were gone all day yesterday, came home to the smell. But it was not there in the morning. It is so weird! We want to gut our bathroom but not right now. I hope it is nothing major!!!! And in our house, it is only the bathtub. Not any other sink drain.

07-05-2007, 10:27 AM
I once had a bathroom like that, and when we gutted it, we discovered that there was no trap on the tub drain. Any way to get access & check, without gutting the place?

07-05-2007, 01:13 PM
Well the bathtub is directly above the basement. I am wondering if I can tell from down there? A co-worker said that perhaps there is stuff stuck around the trap? He also said, maybe that stain on the tub is from mold down in the drain releasing a gas??
Why would it not have smelled b4 tho? We've been there 4 yrs. in Aug. and have never smelled this stink until a month ago....not once. So if there was no trap then wouldn't it have kind of always smelled?
Having all these issues makes me WANT to gut it! I just wish I had the $$!

07-06-2007, 12:42 PM
If the basement ceiling isn't finished, it should be easy to check if you have a trap - it is a loop that will hold water under the drain. While there, check to see if there is a vent (a pipe going up from the area of the drain). A vent is required to keep the trap from getting siphoned dry when other things drain. If you don't have a vent, that could be causing the smells as a dry drain is a direct path to the sewer. The next time this happens, pour some water down the drain and see if it stops smelling. Also, if you place your ear near it, if it is dry, you might be able to hear water draining from other pipes. A full trap will usually block most if not all of that sound as well as the smells.

08-08-2007, 07:50 AM
I am going to show the fiance this thread tonight and have him go investigate in the basement. Thanks so much for all your help!

08-16-2007, 06:05 AM
Well after checking out our drain from the basement (the ceiling is not finished), we came to the conclusion that we have NO p-trap!!!! Or an s-trap...no where for water to sit and keep the sewer gas out. The sewer gas is coming from the drain and from the tub drain stopper on the bathtub wall. So we have to install one. Is this a difficult task that requires a plumber or is it something we can do on our own?

08-18-2007, 12:42 PM
depends how much you are willing to learn. Takes a little figuring things out, like a child's 3D puzzle, but once you see how it can be done, you'll say that it was obvious.

Gluing it in place is easy too, once someone shows you how or you practice once or twice somewhere else.