Pump hums but will not start spinning (single-speed or two-speed Hayward pump).

Safety first: Turn off power at the breaker. Capacitors can hold a charge; discharge safely before handling.

• Check impeller rotation: Remove the pump basket and reach in to feel the impeller (or use the shaft at the rear of the motor). It should turn freely. If jammed, disassemble the wet end and clear debris.
• Inspect bearings: If the shaft is very stiff or noisy when turned by hand, the bearings are likely seized and the motor should be replaced or rebuilt.
• Test/replace capacitor: Locate the start capacitor on the motor (often under a hump-shaped cover). Discharge it, then test with a capacitance meter. Replace with a Hayward-specified capacitor of the same µF and voltage rating if out of tolerance.
• Verify voltage: Confirm correct voltage at the motor terminals while starting. Low voltage can prevent startup.