Relentless sewer gas smell PLEASE HELP!

I have had a sewer gas smell coming from beneath my toilet for 2 months. Here is the info:
-no leaks
-toilet is one year old
-new flange
-new wax ring
-all pipes in crawl and attic are tightly sealed and no obvious cracks or leaks
-roof stacks checked
-smell is intermittent
-flange sits slightly above tile
-have had 3 plumber and a home inspector confirm no leaks and proper pipes
-home was built in 2014 and I am only owner
-no other toilets smell


I am desperate to solve the problem. Does anyone have any advice. All obvious avenues have been addressed.

Could it be coming from a non p-trap drain (or a dried up trap) at a bath or shower or sink adjacent to the toilet?

What kind of toilet? If seen those toilets with the plastic boot adapter have a ripped seal where the toilet discharge slips in cause the same thing your describing. Has anybody pulled the toilet off?

Hi! Yes we have pulled the toilet off and had a new flange installed (not because it was lose, old or broken...I am just that desperate). New wax rings...I will attach a picture of the toilet but I do wonder if somehow I have a faulty one?

Where is the plastic boot adaptor?

Vent line (running up the wall behind or next to your toilet to the roof) could have a bad glue joint, which has opened up.

A camera down the vent from the roof might see that.

Or a carpenter might have nailed into it, when putting up that baseboard or wood paneling or trim.

If all the obvious has been done it’s time for a smoke test

I also would throw in a smoke bomb before I paid $ to search with a camera

Rickyman, that is a great idea.

Where do you get access to inject the smoke?
Maybe from a cleanout in crawl space, or out in the yard?
How do you generate it safely?

That type of test could be used for a lot of issues on here.

EDIT: Found a cool Youtube vid showing a sewer line smoke test.
Correction, this vid was goofy, link has been deleted.
See my next post for a good vid.

We do smoke tests on modular homes. Never done one through a sewer cleanout but it s a great idea. Always done them through the roof. Bought smoke bombs while driving through pa. They look like m80s. If you have a leak or bad joint the house fills with smoke. You need a sealed container not inside the house. I have used ac boxes with 4" outlets and a dryer vent. throw the bombs in and cover it with some kind of lid using a boat blower and a battery. awesome smoke.

Here is a good video, using a professional smoke blower, and what seems like a safer method.

He is not dropping lit smokers into the sewer, and he is using lower pressure which should not blow smoke right through the fixture traps.

Thank you everyone- scheduled a smoke test! I’ll post the final verdict!

That first video was a joke.
I think someone should leave the link to this 2nd video back on the first video.

Yes, I will delete that first video link.

A wax seal can leak sewer gas and not water depending on where its at. I would replace the $3.00 seal again and then
do the smoke test if it still stinks.