AboutDavid Deal Expertise Indoor air quality, mold, compliance questions as well. Also, expert on lead, asbestos, radon, and most any other environmental/industrial hygiene issues.
Expert: David Deal Date: 6/16/2008 Subject: Sewer smell in one bathroom
Question There is a sewer smell that comes through the AC vents only in my bathroom. It's not all the time but maybe once every other day. The AC man said there was nothing in the ducts. Where can it be coming from?
Answer It is possible if you have flex ducts that there is water in the insulation. The ducts will feel heavy and usually sag there.
Also, it may be plumbing related. If you check out the entire duct system, nothing in them or in the insulation, then check for leaks on the return side near a sewage line. Barring that, I'd call a good plumber to check out your system.
