Originally Posted by norty1
Sounds like some construction debris. Can you run a fish tape up in the outside drain with the valve open and dislodge it?
BTW stand clear when you do it.
That is what happened to ours. I use a Sewer Solution so there is a clear plastic fitting that allows me to see what is coming out of the drain (very entertaining
). Anyway, when our RV was new there was a piece of construction debris that blocked the hose to the Sewer Solution that I had to clear out before it would drain completely. Maybe a trip back to the dealer would be best since the unit is so new.