We moved into a new house, 18 years old, and the master bathroom - specifically coming from the toilet- now has an intermittant sewer smell. We are on an aerobic system and had the system serviced (pumped out and filter changed) July 13th. The smell began shortly afterwards. I believe it is coming from the wax ring area because the toilet has a little bit of movement and I just found that the rug around the toilet was a little damp (and, not for the obvious reasons). Also, we have flushed the toilet vent stack with a hose and it was clear. Before we undertake replacing the wax ring, are there any other ideas of the cause of the smell? Thanks for helping!