I live full-time and only turn it on when I need it. You don't need to leave it one for a full cycle either when turning it on. I turn it on only long enough to insure that I get a warm shower. Get to know your water heater and how it acts in different temps to learn the best method. I usually get 8 to 9 months on my 80 pound LP tank while doing it this way. Leaving it on 24/7 I'm sure it wouldn't last half that long.