This may sound like an odd question so I'll give a little background first. I'm a little OCD about flushing my tanks, ok ok, I'm A LOT OCD about flushing my tanks. I've been in a couple campers that...
I am not OCD. I have a 1990 fiver that has a tank flush installed. Works just fine. Never a problem. However I know of 2 cases where the compulsive types got into trouble by shutting the drain valve with the unit flushing and then getting distracted. Overflowed the tank onto floor of coach. There is too much of a good thing.