Emerson conditions-White Rodgers 21M51U-843 Universal 2-Stage HSI 3-Speed Circulator Furnace Kit

The Emerson conditions-White Rodgers 21M51U-843 Universal Control Kit functions with two-stage hot surface ignition in HVAC systems and is designed to operate at three speeds for simpler installation and improve furnace efficiency through model replacement. The 120V nitride ignitor included in this system supports both 80V and 120V hot surface ignition systems. This control kit delivers three benefits improving system reliability and reducing technician inventory requirements while adding diagnostic LED indicators for better troubleshooting. This kit enables simple furnace upgrades while protecting heating system safety and efficiency and extending the durability of system equipment.