Raypak pool pump hums but does not start; may trip breaker after a few seconds.

Safety first: Turn off power and lock out the breaker before touching the pump.

• Check for mechanical blockage: Remove the pump lid and basket. Reach into the impeller area and attempt to spin the impeller with a screwdriver. Clear any debris.
• Spin motor shaft: At the rear of the motor, try to turn the shaft by hand. If it is stiff or frozen, the motor likely needs replacement.
• Inspect capacitor (if external): Some Raypak pumps have an external capacitor under a cover. Discharge it safely and test with a capacitance meter; replace if out of spec.
• Verify voltage: Confirm correct voltage at the pump terminals under load. Low voltage can prevent starting and must be corrected by an electrician.