Sewer Smell In Bathroom, need help!
Last week we started noticing a sewer smell in our kids bathroom. It is a dual sink vanity bathroom with a seperate room with the toilet and bathtub/shower. All drains are used regularly. Our house is a one story, built in the mid 80s and this bathroom is used daily. I have tried a number of things to fix the problem and continue to have the sewer odor problem. Here is a list of things I've done so far:
1. Checked attic space for dead rodents. Didn't find anything noticeable but the house has had rodent problems in the past. No smell in the attic.
2. Ran a 25 foot auger into each roof vent pipe, followed by a jet spray of water from the hose. As far as I can tell there were no clogs, though I seemed to hit some turns in the vent pipe.
3. Checked for clogs in the toilet and both sink drains. Didn't find any. Checked for clogs in bathtub up to the J trap, didn't find anything. Did not go back deep into bath drain. Possibly a clog further back?
4. Replaced wax seal on toilet. Didn't seem to be a problem and the smell is still there afterwards.
5. The smell seems to be strongest and most pinpointed close to the ground between the toilet bowl and the side of the bathtub. They are right next to each other with about 1-2 feet between then.
6. It seems that the smell is coming out of the sinks, but not as strong. Both the vanity room and the toilet/bathtub room have the smell.
7. I did install a new flushing mechanism in the toilet a few weeks ago. As far as I can tell the installation is correct and the toilet flushes. It's a low water flushing mechanism so the flush is not as strong as before.
8. The smell has slowly crept into our living room area but is not strong there and not always there. Might be the odor just carrying over.
I would appreciate any insight that anyone has. I'm stumped and am hoping there is a home fix that I can do before shelling out big money for a plumber. I'm thinking that I may have a a broken vent pipe somewhere in the house or a broken line below the house. Crossing my fingers that this is not the case!
Thanks in advance for all help!