Aqua Terra Backyard
Century HSQ165 1.65 HP Square Flange Pool Pump Motor
Century HSQ165 1.65 HP Square Flange Pool Pump Motor
Century HSQ165 1.65 HP Square Flange Pool Pump Motor
The Century HSQ165 Pool Pump Motor is a 1.65 HP single-speed replacement motor built for compatible pool and spa pumps that use a 48Y square flange, threaded shaft motor. Designed for residential pool pump applications, the HSQ165 is a popular replacement choice when the existing motor is noisy, seized, overheating, tripping the breaker, or no longer starting reliably.
This motor is commonly used on pump setups that require a 1.65 total horsepower, 3450 RPM, 115/230V, square flange motor. Before ordering, always match the motor frame, flange style, voltage, horsepower, and shaft type to your existing motor and pump wet end.
Why Buy the Century HSQ165 Motor?
- 1.65 HP pool pump motor for compatible pool and spa pump applications
- 48Y square flange design for pumps that use a square-flange motor mount
- Threaded shaft motor for compatible impeller-style pool pump assemblies
- Dual voltage 115/230V operation for flexible replacement wiring options
- Single-speed 3450 RPM performance for standard residential pump applications
- Centurion Pro / Century replacement motor family trusted throughout the pool industry
Product Details
| Brand | Century / A.O. Smith / Regal Rexnord |
| Manufacturer Part Number | HSQ165 |
| Motor Type | Pool and Spa Pump Motor |
| Horsepower | 1.65 HP / 1.65 THP |
| Voltage | 115/230V |
| Speed | 3450 RPM |
| Phase | Single Phase |
| Frame | 48Y |
| Flange Type | Square Flange |
| Shaft Type | Threaded Shaft |
What Pump Does the Century HSQ165 Fit?
The Century HSQ165 is a replacement motor, not a complete pump. Fitment is determined by the pump wet end and the original motor specifications. This motor is intended for compatible pumps that use a 48Y square flange motor with a threaded shaft.
When replacing a pool pump motor, do not match by horsepower alone. You should also verify the frame, flange, voltage, shaft style, service factor or total horsepower, and the pump model. A motor can be the correct horsepower but still be wrong if the pump uses a different flange or shaft type.
ATB Fitment Tip
The HSQ165 is a motor only. It does not include the pump housing, seal plate, diffuser, impeller, shaft seal, gaskets, unions, or plumbing parts. If your old motor failed, we strongly recommend replacing the shaft seal while the pump is apart to help prevent leaks into the new motor.
When Should You Replace Your Pool Pump Motor?
- The motor hums but will not start
- The motor is loud, grinding, or has failed bearings
- The motor overheats or shuts off during operation
- The breaker trips when the pump tries to start
- The motor shaft is seized or difficult to turn
- The motor has water damage from a leaking shaft seal
- The existing motor label matches the HSQ165 specifications
Recommended Installation Notes
When installing the Century HSQ165, inspect the full pump assembly before reusing old parts. A leaking shaft seal is one of the most common reasons pool pump motors fail. If the seal leaks, water can travel along the motor shaft and damage the bearings or electrical components.
For best results, replace the shaft seal, inspect the impeller, check the diffuser and diffuser O-ring, and confirm the seal plate is not cracked before installing the new motor. Always wire the motor for the correct voltage and follow all local electrical codes.
Commonly Replaced With This Motor
- Pump shaft seal
- Seal plate gasket or O-ring
- Diffuser O-ring
- Impeller screw or impeller hardware, if used on the pump model
- Motor mounting bolts, if existing hardware is corroded
- Damaged seal plate or diffuser, if cracked or warped
Frequently Asked Questions
Is the Century HSQ165 a complete pool pump?
No. The HSQ165 is the replacement motor only. It does not include the pump wet end, basket housing, lid, seal plate, diffuser, impeller, shaft seal, or plumbing connections.
What horsepower is the Century HSQ165?
The Century HSQ165 is commonly listed as a 1.65 HP / 1.65 total horsepower pool and spa pump motor.
Is the HSQ165 115V or 230V?
The HSQ165 is a dual-voltage motor rated for 115/230V. The motor must be wired correctly for the voltage being used at the equipment pad.
Is the HSQ165 a square flange motor?
Yes. The HSQ165 is a 48Y square flange motor with a threaded shaft. Confirm your existing motor uses the same frame and flange style before ordering.
Should I replace the shaft seal when changing the motor?
Yes. Replacing the shaft seal is strongly recommended whenever a pool pump motor is replaced. A worn seal can leak water into the new motor and cause premature failure.
Will the HSQ165 fit my pump if the horsepower matches?
Not always. Horsepower is only one part of motor matching. You also need to confirm the frame, flange type, shaft type, voltage, total horsepower, and pump model.
Order Century HSQ165 from Aqua Terra Backyard
At Aqua Terra Backyard, we help pool owners and service professionals choose the correct replacement parts without guessing. The Century HSQ165 1.65 HP Square Flange Pool Pump Motor is a dependable replacement motor for compatible pool and spa pumps that use a 48Y square flange, threaded shaft motor.
Need help confirming fitment? Send us a photo of your existing motor label and pump model label before ordering. We can help verify whether the HSQ165 is the correct replacement motor and recommend the proper shaft seal and pump hardware to complete the repair.
