I must be getting senile
but the other day I inadvertently left the water running in my 2860DS bathroom sink. With the noise of the overhead exhaust fan, in a hurry, etc... and of course don't forget the senility setting in, I really did leave it on, couldn't blame anyone else but myself...
Anyway, unbeknownst to me, I'm sitting outside enjoying the nice Florida weather when I heard water leaking out of the RV. I quickly found the outside kitchen sink completely filled with water and overflowing. The outside kitchen water faucets were off.
I made a quick dash inside the coach and found the shower also had a couple inches of water in it. At this point I didn't know the faucet in the bathroom was running full bore.
I quickly ran outside and emptied the galley (rear kitchen's sink waste tank) tank, the water in the outside kitchen sink drained out. I then drained the grey water tank, I noticed it was filled to capacity. I closed the grey tank drain valve and thought a minute what could be going on, was a pipe broken somewhere and draining into the tanks? After thinking for a couple minutes, I opened up the grey tank valve again, more water!! Water somehow somewhere was running! Going back into the coach, I decided to check all faucets and that's when I found the bathroom sink faucet running.
Dumb mistake on my part, but I did learn something about the 2860DS. The grey water tank is evidently connected to the galley tank, I don't know the purpose, perhaps to give more grey water capacity? But the grey tank evidently filled with water and then an overflow pipe must go into the rear kitchen's galley tank, hence the outside kitchen sink filling with water.
Sometimes one learns the hard way