Black tank flush floods my bathroom and underbelly with fresh water

[Second Chance]

Was the problem cause by freezing/winterization? It just occurred to me that I did not do anything to winterize that black tank flush port before we returned from FL in Feb. What do people do to winterize that line?

Usually blow it out with compressed air. If ice formed in the line or the vacuum breaker, it could have cracked it. It still would be helpful to know the answers to my questions in my last post...

Rob

[Hoopy Frood]

Those plastic vacuum breakers are known to fail. There are brass ones available to replace them.

[BHutch]

Was it black water coming directly from the toilet? I've never heard of that before unless the black tank is completely full and the waste water is coming up through the toilet valve. In that case, it's not a problem with the vacuum breaker but rather with the tank and drain. Can you clarify a bit more?

Rob

Hi Rob,
Thanks for all the suggestions. The last time I tried to do the black tank flush, it was a minor disaster. This time, after some internet research and some help from you guys, everything went exactly as it should. I am only about 9 months into this big 5th wheel adventure, still a novice.
Thanks again
Hutch