Lennox 53K80 Fan Timer Kit

The Lennox 53K80 Fan Timer Kit (replaces LB-90157A) is a critical OEM replacement component engineered for precise fan motor orchestration in Lennox Pulse G21 and high-efficiency furnace series. This HVAC control board integrates a sophisticated fan timer control circuit that manages the post-purge and pre-purge cycles of the blower motor to optimize heat exchanger thermal discharge. Designed for high-duty cycle applications, the kit includes the primary 53K80 circuit board and required mounting hardware, facilitating a direct drop-in replacement for legacy part numbers including 97H03, 79J65, and 51K46. As a veteran-grade furnace replacement part, it ensures the induction and blower timings remain within factory specifications, preventing limit-trip scenarios and maintaining static pressure stability across the plenum. Its voltage-regulated design supports consistent fan speed control and 24VAC logic signaling, making it the industry standard for restoring original equipment performance in older Lennox heating systems.

• OEM Compatibility: Engineered specifically for Lennox Pulse G21 units and compatible furnace models, ensuring seamless integration with existing 24V wiring harnesses.
• Precise Cycle Management: Regulates the timing of the blower fan to extract maximum residual heat after the burner cycles off, improving overall AFUE performance.
• System Protection: Helps prevent heat exchanger overheating by maintaining strict control over fan "on" and "off" delays.
• Comprehensive Kit: Includes the upgraded LB-90157A board and necessary mounting components to address common terminal oxidation or relay failure issues.

• What Lennox models are compatible with the 53K80? This kit is primarily utilized in the Lennox Pulse G21 series and various model numbers such as the LF24-75A-1. Always verify the part number on your existing board.
• Can this board replace a 97H03 or 76H31? Yes, the 53K80 is the official manufacturer-designated replacement for legacy part numbers 97H03, 79J65, 76H31, and 51K46.
• Does the kit include mounting standoffs? Yes, the kit includes the essential hardware needed to secure the board to the furnace control cabinet.

This item is not eligible for free shipping.

Disclaimer: While we strive for 100% accuracy, product data and specifications are subject to change. Please contact our team to confirm compatibility or technical details before purchasing.