Reznor 209121 Fan Blade

The Reznor 209121 Fan Blade is a critical OEM replacement part designed for high-static unit heater applications, ensuring optimal heat exchanger cooling and consistent CFM delivery. This 23-inch diameter fan blade features a precision-engineered 35-degree pitch and a 3-blade configuration to balance air movement with motor load efficiency. Operating with a counter-clockwise (CCW) rotation, it integrates seamlessly with 1/2-inch bore motor shafts, commonly found in Reznor UDAS and UDAP series heaters. For technicians, maintaining the original factory pitch and diameter is essential to prevent high-limit tripping or premature venter motor wear. Constructed from durable materials to withstand the thermal stress of industrial HVACR environments, this axial fan blade provides the aerodynamic performance required for commercial gas-fired heaters. Proper seating on the shaft is vital for maintaining the factory-specified clearance, ensuring vibration-free operation and reliable airflow across the combustion chamber.

• Optimized Airflow: The 35-degree pitch is calibrated for specific Reznor unit heaters, preventing stagnant air and overheating.
• Precision Balance: Reduces mechanical stress on the fan motor bearings, extending the service life of the drivetrain.
• Industrial Durability: Robust 3-blade design resists warping under high-ambient discharge temperatures.
• Direct Compatibility: Designed for an exact fit on 1/2-inch motor shafts, eliminating the need for hub adapters or field modifications.

How do I confirm the rotation of the Reznor 209121?
This blade is CCW (Counter-Clockwise) rotation. When standing behind the motor looking toward the discharge, the blade rotates to the left. Using a clockwise blade on a CCW motor will result in zero airflow and immediate system lockout.

What happens if the fan blade pitch is slightly bent during installation?
Even a minor deviation from the 35-degree pitch can cause significant motor amp draw fluctuations or vibration. If a blade is bent, it should be replaced rather than straightened to maintain factory HVAC efficiency.

Is this blade compatible with other 23-inch HVAC units?
While it shares a 23-inch diameter and 1/2-inch bore, its specific 35-degree pitch is engineered for Reznor airflow requirements. Always verify the part number against your model’s technical data sheet to ensure the motor can handle the static load.

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.