Pump hums loudly when switched on but does not spin; may trip the breaker after a few seconds.

Safety first: Turn off power and confirm the pump cannot start unexpectedly.

• Check for mechanical jam: Remove the pump lid and basket. Try to spin the impeller or motor shaft by hand (use a screwdriver on the shaft end if accessible). If it will not turn or feels gritty, disassemble the wet end and clear debris or plan for bearing replacement.
• Inspect capacitor: Locate the capacitor housing on the motor. Discharge the capacitor safely, then test with a capacitance meter. Replace if out of tolerance or visibly swollen.
• Seal drag: If the mechanical seal has leaked, rust and scale can cause drag. Inspect the seal area for signs of leakage and replace the Kripsol mechanical seal kit if needed.
• Breaker trips: Avoid repeatedly resetting a tripping breaker; this indicates high current. If the motor remains locked after clearing obstructions and replacing the capacitor, the motor likely needs replacement.