Have a new home with a septic system, 6 months old. It seems after a rain of any magnitude (>1/2") I get a horrible sewer gas smell in one of my bathrooms. The bath is located on the 2nd floor. I have bathrooms on the 1st floor with no problems and an other 2nd story bath... no problem. The toilet is a Mansfield Maverick comfort height and I have 2 others of the same make (one up one down). The smell seems to be radiating from the toilet bowl but hard to tell exactly. Is this a septic field/system issue, piping issue or toilet issue? Any help is appreciated... my builder is at a loss and the plumber is equally confused.

If it were a septic tank issue wouldn't it affect more then just one toilet? One cause could be a ruptured wax seal. If the seal were ruptured the horn on the bowl would still direct the discharge past the flange into the closet bend but a faulty seal would allow sewer gas to escape. As to the odor being worse after it's damp, all smells seem to concentrate closer to lower levels when it's damp.l my bet's on the toilet. Good luck, Tom

OK, I tried to determine the source of the smell. I Saran Wrapped (TM) the toilet bowl and the odor went away. So, the source of the problem must be the toilet bowl leaking gasses back into the house. Mechanically, what has failed on the toilet or how can that be?

Was my last post not explicit enough? I thought you might have a ruptured wax seal. Will you be pulling the toilet yourself and will you need instructions if you do? Regards, Tom