black tank fill mystery

[Cmitchell]

So I have a mystery. I recently purchased a 2022 Forest River Wildwood Heritage Glen 36FL Elite series 5th wheel. I took it on its first trip last week for 5 days, getting back last night. This morning, I went to the local camping world and flushed both of my 2 grey and 2 black tanks. (I have had a travel trailer previously, so I know the process). I then brought my camper back to my house and proceeded to sanitize the freshwater tank as I had to put well water in my fresh tank halfway through my trip. When I started, my black tanks were reading empty. During my second rinse cycle, I noticed my black tanks were at 2/3s full again. I hadn't used either toilet since I flushed them at Camping World. I had been running the water through my kitchen sink, both bathroom sinks and my shower to flush the bleach water. When I stopped using my bathroom sinks, the black tanks stopped filling. I took it back to camping world and sure enough, both my black tanks had quite a bit of fluid in them, so my sensors weren't wrong.

I thought all rv sinks drained into grey tanks. is it possible that my bathroom sinks drain into my black tanks? i can't think of any other reason that my black tanks would have filled back up as I didn't think there was any other connection between my grey and black tanks. Anyone else have any ideas?

[Reverse_snowbird]

Originally Posted by Cmitchell

I thought all rv sinks drained into grey tanks. is it possible that my bathroom sinks drain into my black tanks? i can't think of any other reason that my black tanks would have filled back up as I didn't think there was any other connection between my grey and black tanks. Anyone else have any ideas?

It's very possible. Our bathroom sink drains into the black water tank. In our case, it's the most efficient way to get water into the black water tank for cleaning. Our macerator toilet doesn't allow a lot of water into the black water tank with each flush.

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