The HTP 7855P-309 Main Control Board is an electronic control component designed for compatible HTP heating equipment, including gas-fired boilers and water heaters. It coordinates essential system functions by receiving input from sensors and managing connected components during heating cycles, ignition, and safety operations. This control board helps maintain proper communication be... https://www.partshnc.com/htp-7855p-309-main-control-board-uft-100w