j-d wrote:
Some Thetford toilets had what we called a "vent" that they called an "overflow" which was a little hole up by the rim connected down to the outlet, below the flush valve. I think they've discontinued that, but I do know they recommended plugging/sealing them to control "odor."
Yes, they have a plug kit they will send you if you have the overflow drain hole. IF the lavy sink vent smells the same as your odor, then odds are it is NOT the black tank. But, as I have told in previous posts, DRAIN both tanks and flush. Install a cup of Pine Sol in the toilet tank and test. IF the odor you get in the RV is Pine sol, it is a black tank problem. If NO odor, then your problem is the gray tank. IF you have a Sealand brand toilet (the brand had the overflow holes) the gasket was more pliable foam rubber and they dry out and then leak both water and odors. How old is the RV? Doug
