This comprehensive White-Rodgers 21M51U-843 kit includes a 120V nitride ignitor and detailed furnace control cross-reference data to eliminate guesswork during installation
Manufactured to meet OEM electrical specifications
It should not be used in the lower position which typically requires a single-pole thermostat without a reset button
it is calibrated with a 150°F fixed open temperature to interrupt the burner circuit during an over-temperature condition and a 110°F fixed close temperature for an auto reset function once the heat exchanger cools to safe operating levels
it is designed for direct immersion into the oil reservoir
Bard 8612-029 Controller Board Els PW 17895 This comprehensive White-Rodgers 21M51U-843 kitThe Bard 8612 029 MC3000 Controller Board is a specialized microprocessor based controller designed for dual unit HVAC systems, specifically those utilizing Bard wall mount heat pumps and air conditioners. This solid state control board serves as the direct 8612 019 replacement, offering enhanced logic for lead lag sequencing, redundancy, and staged cooling. Engineered for telecommunications shelters and modular classrooms, the Bard 8612 029 manages