Today’s hot water heaters come pre-set from the manufacturer at 120°F. Older hot water heater models can be set at medium. In gas models, the thermostat dial is usually located on the front of the gas valve. On electric models, the thermostats are generally found behind the panels on the side of the tank. The temperature can be adjusted. Ideally, you want the temperature to be hot enough to minimize bacteria growth, but not hot enough to provide a serious safety hazard. Just keep in mind that the electricity should always be turned off prior to performing any water heater maintenance to prevent shock.