Upgrade your HVAC system with the Lennox 15D57 Defrost Board with Sensor Replacement Parts, designed to enhance the performance of your heating, cooling, and air quality systems. This genuine OEM part is essential for maintaining efficiency during winter by preventing coil freezing without external monitoring. The defrost board optimizes defrost cycles, improving system efficiency, while the included sensor ensures accurate temperature detection. Installation is straightforward for HVAC professionals, making it a convenient choice for system maintenance. Compatible with a wide range of Lennox models, this versatile defrost board replaces multiple older versions, ensuring reliability and longevity. Key features include a dependable sensor and compatibility with various Lennox models, making it an essential component for many HVAC systems. With a weight of 14.4 ounces and dimensions of 8 x 8 x 8 inches, it includes the 81W99 defrost board and 28W71 sensors. Trust Lennox, a leading brand in HVAC solutions, to keep your system running smoothly all winter long.