Pump hums but does not start, then trips the breaker or internal overload.

Safety first: Turn off power and allow the motor to cool. Do not repeatedly reset a tripping breaker.

Steps to check:

• Spin shaft manually: Remove the rear motor cover and try to rotate the shaft with a screwdriver in the slot or wrench on the flats. It should turn freely.
• Inspect impeller for jams: Open the pump housing and check for debris lodged in the impeller.
• Check capacitor: On Jacuzzi single-speed pumps, locate the start/run capacitor under the motor cover. Look for bulging or leaking. Replace with the exact µF and voltage rating if defective.
• Verify voltage: Confirm the pump is wired for the correct voltage per the nameplate.

If the shaft is stiff or noisy when turned by hand, the motor bearings are likely failing and the motor assembly should be replaced.