Most people are comfortable with their hot water set at 120°F, which is also the new standard that manufacturers use when pre-setting your water heater temperature at the factory. If you have an older model, set the thermostat at medium. On a gas model, there is a dial on the front of the gas valve. On electric models, the thermostats (there may be two) are concealed behind the two panels on the side of the tank. NOTE: Turn off the electricity before removing the panels. There are exposed wires behind the panels containing HIGH VOLTAGE.