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 don't close mine, not because of the sticker but it's just the way I do it. I empty the black and leave the valve open and while the grey is draining run the flush. I run the flush the whole time the grey is draining.
