Looking for fresh water drain

Trace the lines from the FW tank to where they exit through the floor. While I don't have a unit like yours, my drain would not drain either and last year I was forced to pump the FW tank dry (almost) with the on board pump. You don't need to drain it entirely dry, if a bit of water freezes in the bottom, no big deal, won't hurt anything, however, I found that I had a blockage in the drain line so I blew the line backwards with compressed air. Problem solved.

Different brand, but my 2007 Montana has a small capped pipe near the rear of the trailer for fresh water tank drain. Also has two small pipes under area near water heater, but those are my low point drains and do not drain the fresh water tank. If you know where the fresh water tank is located, the drain should be under that area, if it has one.

Have you looked under slide out between the wheels and/or for/aft of wheels

Regarding the fresh water drain on my 05 Alpenlite fifth wheel:

Thanks for all your replys. Even the dealer I bought the fiver from did not know where the drain was.

The panel showing amounts in the tanks showed three tanks. There was the black water and gray water tank on the left side of the trailer with pull handles for draining. Also there was an identical pull handle by the entrance steps on the right side of the trailer. I assumed it was for the kitchen drain. Just to make sure I pulled the handle and fresh water gushed from the center of the fresh water tank. Problem solved. Even the books with the trailer did not give a clue.

wow driver, good post, that one was definitely over my head. :R

Glad that it was fresh water that gushed out at you. Were you taking videos in case it wasn't the fresh water valve?

My AF has a similar setup - although it's labeled making it much easier to identify. Fresh tank has the same type of guillotine valve as the others except it dumps directly from the fresh water tank to the ground instead of going out through the dump hose connection. I'm really surprised you don't have 3 other valves (black, grey-bath, grey-kitchen). I'm pretty sure my brother's Alpenlite Valhalla is set up that way.

We had a Coleman pull trailer for a few months. The panel showed three waste tanks but it actually had only two. It looks like the Alpenlite is the same way.