Greetings,
Mr. D. Well, plugged vent line would be my first guess as well. Not hard to check. Remove cap (gingerly), put a water hose into the vent and give it a shot of water (to backflush). Double check that your tank is NOT full or you'll have more than egg on your face.
As far as the odor goes. A plugged vent will encourage the growth of anaerobic bacteria and that's NOT what you want. You want the aerobic bacteria. Them's the bugs that break down the waste with little odor. I hope you haven't been using those formaldehyde based head chemicals to control odors. BAD stuff!
__________________
RTF
|