Would love for PowerfulREM (Robert) to come back and clarify but for now I'll just add that I don't recall him saying exactly HOW the water got everywhere; did it simply overflow from the toilet, leak from the toilet seal, or did the tank actually rupture. (The tank rupturing doesn't seem a natural way to get water in the floor ducts...)
The reason for asking clarification is to then further pursue whether the "recommended procedure for flushing" includes leaving the black termination gate open or closed during flushing.
While certainly not a 'seasoned' camper (we only have a couple of dozen trips to our credit), I've been a devotee of this forum since our purchase of the 271RL. GREAT source of knowledge and I use it regularly. And it was here that I got my process of black tank dumping/flushing. That process being:
- Start flush water
- As soon as "full" light is lit, dump.
- Wait until clear water is flowing out of the dump tube.
- Close gate and refill until "full" light is lit.
- Repeat above until convinced all is clear.
I agree with the sentiment that "you can't trust the little red light tree". That's why my wife monitors both that AND a view down the toilet while flushing is underway. We also have a window next to the dump valve open so she and I can stay in communication and keep track of the black tank level.
If the above is acceptable, is there ANY reason to be concerned about rupturing the tank by flushing...? I would hope the answer is 'no'.