Your water heater should never be set to deliver more than 120 degrees, that is typically the warm setting or the spot on the dial that has the notch. Believe it or not tank type water heaters can have temperature swings as high as 25 degrees in the tank. The new Bradford White heaters have brought that swing down to a maximum of 10 degrees but the difference between 120 and 130 degrees is monumental when it comes to the time it would take to get scalded. The best way to control the delivered temperature is to install a mixing valve on the water heater with a thermometer directly after the mixer. This installation has 2 very important and beneficial functions. The first is that you are guaranteed to deliver the exact temperature that you set it at with almost no deviation. The second and for some best result is that by installing this mixing valve you have to potential of increasing the capacity of your existing water heater by as much as 40%. Yes, 40% more hot water out of the same heater.