sewer tank flusher

[tandastevens]

Help. I have a 2012 keystone cougar. My first trip out this year, I hooked up to the sewer flush valve with a water hose. Instead of flushing out the black tank, water came out from behind the tank flush hookup. Nothing went into the sewer. Any ideas?

[geo]

Oh yes. Another victim of the black tank vacuum valve. Do a search, on black tank flush or black tank system - there is probably several hundred posts, including a diagram I posted.

Ron