The Rheem Power On/OFF Switch, part number RTG20319DJ, is a vital component for Rheem tankless gas water heater systems. This switch controls the electrical power supply to the unit, allowing users to easily turn the heater on or off as needed. Engineered for durability and user convenience, it ensures reliable operation and safety. Specifically designed for Rheem units, this power switch guarantees optimal functionality, providing simple and efficient control over the water heating system.