My Septic System Stinks up my bathroom at night. Anyone know why? I also had this problem at a place I worked at which was an older house. It doesn't stink during the day, just at night. I think it may be the wax seal but I don't know.
Thanks

The first place I would check is up in the attic. A open or cracked vent would keep the sewer gas up there in the daytime but when it got colder the gas would get heavier and fall.
The next thing I would check is the wax seal. Let me know if they worked. Good luck, Tom

Thanks for the answer but if it's the wax seal why would it only stink at night?