Sewer odor

[Meaghan]

Hello!
We purchased our home last September and the sewer was finished being replaced as of March this year. For the last couple of months now we have noticed if the windows in the basement are shut then sewer odor fills the basement and travels upstairs. Even within a few minutes of shutting the windows. We have had a few professionals out to check on the issue. There are no empty traps, all drains are appropriately trapped, and there are no drains that could even vent into the basement. My husband and I are really capable and this one thing has us stumped! One idea someone had is that if for some reason the person who out the new system in didn't pump the old one before it was crushed then it could be decomposing under ground and being sucked in through the cinder blocks which are porous. So we have put down a sealant on the walls and floors. Unsure if this is helping. Please help!

 

[Mliu]

Do you have any plumbing fixtures in the basement or in the basement floor? A floor drain? A backwater valve? A cleanout?

Tell us more about the sewer replacement.

 

[Sponsor]

 

[ImOld]

pump the old one before it was crushed

What does that mean? Do you have a septic system?

 

[Reach4]

Try to isolate smells by closing doors, and/or covering drains or other suspects with a cheap plastic drop cloth. Tape one over the area of wall where you suspect the smell is infiltrating. After a period of time, see which side of the plastic sheets the smell is strongest at.

 

[Plumbs]

Have you had a smoke test or peppermint test done? I'm assuming if you've had several professionals at least one would have recommended one. If not then you've had the wrong people out.
Sometimes these things require more than a visual inspection.