Lennox 43J58 Inducer Assembly

The Lennox 43J58 Inducer Assembly is a high-performance direct replacement draft inducer engineered for precise negative pressure regulation in gas-fired heating systems. This OEM combustion air blower, manufactured by Fasco (Model 7121-8774 / Type U21B), features a 1/30 HP, 115V shaded pole motor operating at a steady 3200 RPM. Designed to ensure safe venting of combustion byproducts, it utilizes a thermally protected, air-over cooled motor with Class B insulation. The clockwise rotation (CWLE) and durable metal housing provide the consistent airflow required to engage furnace pressure switches, preventing system lockouts often caused by inducer failure. This assembly replaces legacy part numbers LB-65734E and 161P05, and is primarily found in Lennox G23 series units, including models G23Q3/4-125-4 through -06. The kit comes complete with a replacement gasket (50J77) and mounting hardware, ensuring a sealed fit to the collector box to maintain furnace combustion efficiency and prevent CO leakage.

• OEM Precision: Genuine 115V Lennox 43J58 blower ensures exact fitment and factory-calibrated static pressure performance.
• Heavy-Duty Construction: Built with a Fasco 7121-8774 motor and metal housing for long-term cycling in high-heat environments.
• Reliable Ignitions: Maintains a concentrated 3200 RPM to reliably close the centrifugal switch or pressure sensor for smooth burner ignition.
• Complete Installation Kit: Includes the critical 50J77 gasket and screws to prevent vacuum leaks at the heat exchanger interface.

What are the signs of a failing 43J58 inducer?
Technicians typically look for seized bearings, a failed thermal protector, or loud chattering noises. If the motor draws more than 1.5 Amps or fails to reach 3200 RPM, the pressure switch will stay open, preventing the furnace from firing.

Does this assembly include the gasket?
Yes, the 43J58 kit includes the required 50J77 gasket. Reusing an old gasket is a common cause of combustion leaks and pressure loss, so always use the provided new seal.

Is this compatible with other brands?
This assembly is a cross-reference for specific Armstrong, Ducane, and Concord models. Always verify your specific furnace serial number and part number (LB-65734E) before installation.

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.