Lennox 21L90 Motor

The Lennox 21L90 is a high-performance, direct replacement motor engineered for residential furnaces and air handlers requiring a 115V 1/5HP 1075RPM configuration. As a genuine PSC (Permanent Split Capacitor) motor, it provides the multi-speed versatility necessary for precise airflow management in Lennox, Armstrong, and Ducane units. This 48-frame blower motor features a 3-speed design, allowing technicians to optimize system static pressure and CFM delivery. It is the verified successor to legacy part numbers 18M25, 18M2501, 51W87, and 86H66, ensuring a seamless drop-in fit without the need for mounting modifications.

Built with a 1/2 x 3-inch shaft and sleeve bearings, the Lennox 21L90 motor is designed for horizontal mounting using a standard torsion flex bracket. The CCWLE (Counter Clockwise Lead End) rotation and thermally protected internal windings maintain operational stability under continuous "air over" cooling conditions. When installing this OEM Lennox 21L90 furnace motor, technicians should verify the 5 MFD at 370 VAC capacitor requirement to ensure proper torque and amperage draw. This 11.55 lb motor provides the reliable mechanical output needed to restore factory-spec air circulation in critical heating and cooling applications.

• Direct OEM Compatibility: Engineered as a drop-in replacement for Lennox 18M25 and 18M2501, eliminating field fabrication.
• Multi-Speed Versatility: The 3-speed blower motor design allows for tailored airflow adjustments across various heating and cooling stages.
• Robust Construction: Features a 48Y frame and sleeve bearings optimized for 115V HVAC motor applications.
• Standardized Fit: Utilizes a 1/2" diameter 3" long shaft, fitting a wide range of OEM blower wheels.

• What capacitor is required for the 21L90? This motor requires a 5 MFD / 370 VAC run capacitor for optimal performance and to maintain proper amperage.
• Can this motor replace a single-speed unit? Yes, provided the voltage and horsepower match; however, wiring must be adjusted for the preferred speed tap.
• Does it include the mounting bracket? This is the motor only; it is designed to fit existing Lennox torsion flex brackets or standard 48-frame belly bands.

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.