We have a sewer gas smell in our upstairs shower. It appears after you've been in the shower and running water for 3 or 4 minutes. I've snaked the shower and sewer vent and imagined some improvement, but it was short-lived. Or the improvement could have been my imagination. Any guesses?

look down inside the drain with a flashlight. you should see standing water. that is the trap seal. without it sewer gas can come back into the room.

the tail piece before the trap probably has a build up of biogunk causing this smell. abrasion with a 50/50 bleach/water mix should solve that.

So, by abrasion you mean getting a brush around the curve of the trap and scrubbing the bleach mixture through the whole business? I'll try that. Thank you.



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I ended up mixing bleach and water and getting a long, twisty brush and really working over the p-trap, as best I could, and it cleared up the smell for the length of one shower, at least. I think I'll have to do that fairly frequently, and maybe it will solve the problem. Does boiling water make a difference?

Not really, the bleach is what kills the smell causing bacteria.