I am trying to find out what can be done about a smell that only shows up when the dryer is on. It comes from the sewer pipe in the basement and we have moved the dryer away from the floor drain thinking that this might be the problem. We also keep fresh water in the drain. As soon as the dryer shuts of the smell disappears. I have had a plumber come out and he put new plumbling in as there was a leak by the bath tub drain and also replaced most of the plumbing in this area as a precaution. We sealed around all fittings old and new and it still is there.Any suggestions?