Black tank Flush
Sticker by the flush hose port says 'drain valves must be open when rinsing blak tank'. Why must they be open as there should be no pressure buildup, or am I missing something?
Forum Discussion
- I think it's just a cover their butt thing. Someone somewhere must have over filled their tank and then blamed the RV company and they had to pay.
I, like you, don't think it could over pressure but you never know.
When I drain & wash my tank I keep the valve closed to fill the tank then empty. I do this several times and just keep a eye on both the level indicator and even open the toilet dump valve to monitor the water level.
That's my take on it, for what it's worth.
Good luck!
