The Rheem Performance Plus 40 Gal. Natural Gas Short Water Heater comes with a 38,000 BTU/hour environmentally friendly low NOx burner that provides ample hot water for households with 2 to 4 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. 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.