Hi everybody,
I have a problem and hope that you may help me.Some months ago I built a big house ( 500 metres squares).There are 5 toilets in this house.A very unpleasent, rotten smell sometimes arise from 2 of these toilets.These 2 toilets are found on the ground floor, near the septic tank.After the rotten smell comes, it just disappear after about 1 or 2 days . But unfortunately it's just a respite and after a while it returns back.Two plumbers have tried to fix the problem, but the bad , rotten smell still comes.I am starting to get desperate.Can anyone help me ? I would also like to say that this house is being used as an office and that the people working there never use the tubs and showers.
Thanks a lot

P.S- Sorry if my English is not perfect, but please understand that it's not my native language.

First make sure that the tubs and showers traps have water in them. Second pull the offending toilets and make sure that a wax ring was installed.