I replaced my 1970 hot water tank with a Rheem tankless system. My 1200sq. ft. cabin is at 8,200 feet elevation with a 100 gallon propane tank. It took my friend and I two days to install it, which included cutting a hole in the logs and using Pex's and SharkBite fittings. The visual diagrams were helpful in developing a plan and buying the necessary propane and water pipe fittings. There is a setting for higher elevation and a temperature gauge that was already wired to go. I am so pleased with the final outcome, the reasonable cost and it's efficiency. No heating water 24/7 anymore. I am gearing up to put a Rheem tankless in my home now.