U.S. Motors variable-speed pool pump displays E08 and will not start; sometimes accompanied by a humming noise from the motor.

Safety first: Shut off power at the breaker and verify the pump is de-energized before attempting to turn the shaft.

• Check for external blockage: Remove the pump lid and basket. Inspect and clear debris from the basket and suction port.
• Inspect impeller for jams: Remove the pump housing bolts and separate the wet end from the motor. Check the impeller vanes and eye for stones, plastic, or other debris. Remove any obstruction.
• Test shaft rotation: With the wet end removed, turn the motor shaft by hand using a wrench on the shaft flat (if provided). It should rotate smoothly. If it is stiff or frozen, the bearings are likely seized.
• Check for impeller rub: Reassemble the wet end carefully, ensuring the diffuser and impeller are correctly seated and not overtightened. An incorrectly assembled wet end can cause the impeller to rub the housing.
• Replace motor if seized: If the shaft cannot be freed or bearings are noisy/rough, replace the U.S. Motors pool pump motor.