A. O. Smith's Signature 100 Series Tall Low NOx 50-Gallon Direct Vent Gas Water Heater provides efficient, reliable hot water for households with 5+ people when sized appropriately. The environmentally friendly 40,000 BTU Low nitrogen oxide natural gas burner delivers 77 gallons of hot water in the first hour. An electronic gas valve provides precise temperature control for optimum hot water delivery without an external power source necessary. The gas valve also includes an LED status indicator for diagnostics reporting and a push-button ignition to simplify startup. This 50-gallon hot water heater has a built-in safety system to reduce the risk of accidental flammable vapor ignitions. A factory-installed temperature and pressure relief valve and tamper-proof drain valve also ensure safe operation. This model is built to last. It features Tank Guard® which is designed to proivde ultimate tank protection and increase lifespan of the water heater. It also features a self-cleaning dip tube to decrease sediment build-up and extend the water heater's overall life. This added protection comes with a 6-year limited warranty to provide peace of mind. Call 1-877-GOLowes to get this water heater installed.