Replacement Control Board

The Lennox 12J99 is a precision ignition control board engineered for reliable HVAC system performance in residential and commercial furnace applications. This integrated furnace control module operates on 24 VAC with a 3-amp fuse rating and measures 53/4in x 41/2in, making it suitable for standard installation configurations. The board delivers fast and reliable ignition control with advanced technology designed to minimize downtime and ensure consistent, efficient operation across compatible Lennox furnace systems. Built with durable construction for long-lasting performance, the 12J99 features diagnostic capabilities that enable HVAC technicians to quickly identify and troubleshoot system issues, reducing service time and improving overall system reliability. Installation and maintenance are straightforward, supporting efficient field operations. This replacement control board is the ideal solution for maintenance, repair, and upgrade applications where dependable ignition control and precise furnace operation are essential. Suitable for both service technicians and facility managers seeking OEM-compatible replacement components for Lennox heating systems.