The other day I was looking at the sheet for the actual No Fuss black tank flush and looking at the install sheet, the sprayer for that is installed about 2" from the top of the tank. The unit also has a vacuum breaker which gave me the idea that maybe some of what I sometimes smell is actually coming from the breaker in the No Fuss thing.
I always seem to notice that the smells come from around the vanity, which would make sense, since you can see the plumbing for this thing. At least I think it is the BTF I see. Either way, what I smell, isn't contiunous, just for a few minutes or so.
Just a thought.
Sometimes I wish I were living in the stone age. Then I would know I'm the smartest person in the world.