Black water in the toilet
I recently finished up a trip and as usual, I dumped my black water and flushed the black water tank several times until clear water showed in the clear connection to the sewage. I then dropped one of those deodorizer pods and flushed about a half gallon of water into the tank and made sure there was clear water in the toilet bowl before driving down the road. When I drove to my next destination, I found some black water back in the toilet, which I just flushed into the black water tank.
Any ideas as to why or how the black water would end up in the toilet? And suggested remedies?
I have a Dometic Model SC 210, which,before going on my trip, I replaced the seal with an OEM seal because it wouldn't hold water in the bowl. The installation went well. A week before my trip, I made sure the seal would hold water in the bowl, and there was no problem.
Thanks for any help and suggestions.