A Navien tankless water heater works by heating up cold water on demand using a built in gas burner to quickly heat up cold water and store it in a small tank. The unit uses built-in technology to recycle heat generated during the heating process, making it energy efficient.
Unlike a traditional water heater with a tank, the Navien tankless water heater uses technology to immediately generate hot water and send it to the tap. Whenever the hot water is turned on, the Navien tankless water heater draws cold water into the unit and passes it through two heat exchangers to heat the water. The first heat exchanger warms the water using recycled heat that is created by condensation of water vapor and other exhaust gas. The unit then passes the warm water through a second heat exchanger where temperature is increased using a gas burner. From there, the water passes a sensor and fan to ensure the water is the correct temperature before being stored in a small buffer tank. The heated water is then sent to the tap. The Navien tankless water heater provides an unlimited supply of hot water and the condensing technology used to preheat the water makes the unit more energy efficient than other types of tankless water heaters.