The Rheem Professional Classic Plus 50 Gal. Natural Gas Tall Water Heater comes with a 40,000 BTU/hour environmentally friendly low NOx burner that provides ample hot water for households with 3 to 5 people. The push button ignition system ensures safe and easy startup. Its maintenance-free combustion air intake system means there are no filters to clean and replace. The self-diagnostic gas control valve monitors system performance. A premium grade anode rod provides long-lasting tank protection. Factory-installed temperature and pressure relief valve and 3/4 in. water connections are included with the water heater for easy installation. This model also comes with an additional 4-year upgrade kit for enhanced warranty protection.