Couple of things to consider; Tank less water heaters require more room to install, have large diameter flues (4"-6"), actually use more gas when they are heating, require annual dis-Assembly and cleaning for proper function, use more water than a tank type, may have adverse affects when dry camping ( you may get cold spells when you shut the water off to lather, etc.), you may not be able to feed it enough propane to it to operate properly in colder climates if your furnace is running, etc.. Just what comes to mind when I think about it. I have installed and removed several of them around here. Personally, I wouldn't have one. In all actuality, if you shut your tank type off when you don,t need it, you will use less propane than the tank less.