The Lochinvar & A.O. Smith 100112016 Combined Controller is an electronic replacement control module designed for compatible BTH 500 Series commercial gas water heaters. It coordinates essential heating operations by processing signals from system sensors and managing temperature regulation, ignition, and safety functions. This controller helps maintain consistent water heating perfor... https://www.partshnc.com/mot19014-trane-16hp-115v-15001200900rpm