Being in the apartment industry as long as I was I found most resideents like their hot water so I always started with 140* then uf the resident weren't happy either due to the recover time due to the family size I would adjust it to 150* I never would set one above 160* Not far from that temperature you start reaching scalding temps. I realize the Dept of Energy states 120* but I would run out in a little while if I set mine that low and somebody would be taking a cold shower.