Nev. Rev. Stat. § 455C.090
Inapplicability of chapter to certain water heaters
The provisions of this chapter and any regulations adopted pursuant thereto do not apply to a water heater if, with regard to the water heater, none of the following limitations is exceeded:
1. An input of heat of 199,999 British thermal units per hour (58,600 watts).
2. A water temperature of 210 degrees Fahrenheit (99 degrees Centigrade).
3. A water capacity of 120 gallons (450 liters).