The Lochinvar & A.O. Smith 100281540 75-Gallon CI Natural Gas Burner Assembly is a replacement combustion component designed for compatible 75-gallon natural gas water heaters. It mixes natural gas with combustion air and produces a controlled flame to heat water efficiently within the tank. This burner assembly supports reliable ignition, consistent heat transfer, and proper burner o... https://www.partshnc.com/100281540-lochinvar-ao-smith-k-fba-nat-75gal-cast-iron