Keep your furnace draft inducer running efficiently with a direct-fit replacement blower wheel. The Fasco 8710-4358 is engineered to match the original dimensions, bore size, and rotation direction of the wheel used in a wide range of Fasco draft inducer assemblies -- restoring proper airflow and combustion performance without motor replacement.
When a draft inducer blower wheel cracks, chips, or becomes unbalanced, the result is reduced combustion airflow, vibration noise, or a furnace that won't fire reliably. Replacing just the wheel -- rather than the entire motor and housing assembly -- is the practical, cost-effective repair for any technician or experienced DIYer.
The Fasco 8710-4358 is a single-inlet, counter-clockwise blower wheel sized at 4-3/4" outer diameter and 1-3/4" width, with a 5/16" center bore. It is rated at 3600 RPM and matches the original part used across more than ten Fasco draft inducer model numbers.
4-3/4" OD and 1-3/4" width match original wheel geometry for correct clearance inside the inducer housing.
5/16" bore fits the motor shaft directly. Counter-clockwise rotation is set at manufacture -- no adjustment needed.
Confirmed fit across 11 Fasco draft inducer assemblies including A136, A137, A142, A165, A168, A224, A225, A227, A158, A280, and A307.
Replace just the damaged wheel rather than the full motor assembly. Reduces repair cost and downtime significantly.
The blower wheel (also called an impeller or squirrel cage) is the rotating component inside a draft inducer motor assembly. Its job is to pull combustion gases through the heat exchanger and exhaust them out the flue before and during the burner cycle. A damaged or out-of-balance wheel reduces draft pressure, can trigger pressure switch faults, and may cause the furnace control board to lock out on a safety fault.
Because the wheel spins at 3600 RPM in a high-temperature environment, even minor cracking or blade damage causes measurable airflow loss. Replacing the wheel promptly restores correct negative pressure at the draft hood and keeps the pressure switch reading within spec.
If the motor shaft and bearings are still in good condition, swapping only the blower wheel restores full inducer performance. This part press-fits or slides onto the motor shaft and is secured with a set screw -- no special tooling required in most applications.
This blower wheel has been confirmed to fit the following Fasco draft inducer assemblies:
Always verify your existing wheel dimensions -- OD, width, and bore -- before ordering if your inducer model is not listed above. A 1/16" difference in bore diameter will prevent proper shaft fitment.
This wheel is cataloged under NBK part number 20538, which is the same component. If you sourced a previous replacement through NBK or an HVAC distributor using that number, this is the identical part.
Replacing the blower wheel on a Fasco draft inducer is a straightforward bench repair once the motor assembly is removed from the furnace:
While the inducer is disassembled, inspect the motor shaft bearing for side-play or roughness. A wheel replacement on a worn-bearing motor will only provide a short-term fix. Also check the pressure switch hose and port for blockages while the assembly is accessible.
If the motor itself shows signs of bearing wear, overheating, or winding failure, a complete Fasco draft inducer assembly replacement is the more reliable long-term repair. Individual Fasco A-series inducer assemblies for common furnace brands are available separately.