WE bought our house 6 months ago and have been having terrible problems with a sewer smell from basement after showers have run (one long one or more than one). We do not have any leaks (water wise) had 2 new vents installed but still it is terrible! Help - it isn't noticeable from any fixture just mostly in basement where the main line goes out to septic. All traps have water in them and had many pipes replaced.

I had this problem once but it was a very long time ago.

I don't remember exactly what I did to fix it, sorry!

I can say that I have a habit now, of pouring a small amount of liquid drain cleaner into each drain in the house once about every 2 months or so.

This not only keeps them flowing well, but also seems to keep any odor under control as well.

If you try this, be prepared for the smell to get a little worse, before it gets better as the cleaner will start to break down some of the build up as it begins to wash it away.

Good luck with your problem.