The Bosch HVAC 8733933939 Diagnostic Control Board is an electronic control component designed to monitor and coordinate the operation of compatible Bosch heat pump equipment. It processes signals from system sensors, switches, and safety devices to help control connected components and support fault diagnostics. Installed within the HVAC equipment’s control compartment, it helps main... https://www.partshnc.com/bosch-hvac-8733933939-diagnostic-control-board