Answer for dan
Hi dan,
I purchased the hot water heater online from sportsmans guide, they have 2 models and i bought the smaller of the two. The water heater is fired when it senses water flowing through it (electricly ignited runninng on 2 d batteries) The system works great and takes up less space than a convential Rv water heater. The batteries have lasted a year and it doesn't seem to burn much propane. The only problem i have had is when the temperature dropped down to about 15% with a 20 mile per hour wind the pipes froze. The heater has a bleed off valve and i had drained it because i knew it was going to be cold so the only hoses that froze were the supply hose and I had used PEX just in case this happened.
As for the drain, when we built the "basement" that we put the shower pan in, I ran a peice of 1 1/2 pvc from the shower drain to the side of the frame and out the back. I also routed the kitchen sink drain down into the same pipe. On the end of the pipe, in the back, i put a pvc 3/4" hose bib on so i could attach a garde hose to evacuate the gray water away from the camp site. This camper is truly a dream to be in! please let me know if you need any help with your mods. The only thing different i think i would have done differently (and i am doing in my new camper i am building) is relocate the fresh water tank to the basement, it lowers the center of gravity and would give more storage room in the camper. ( I will go out to the camper tomorrow and get the name of the water heater off of the unit)
Thanks and "cheers"
Randy