Pump hums but does not start; may trip the breaker after a few seconds.

Safety first: Turn off power and discharge capacitors before handling. Capacitors can store dangerous charge.

Step-by-step checks:

• 1. Try to spin shaft: With power off, attempt to rotate the motor shaft at the rear fan. If it spins freely, the issue is likely electrical (capacitor or winding).
• 2. Inspect for blockage: Remove the pump lid and basket, check for debris in the impeller area.
• 3. Locate capacitor: On many Davey pumps, the start/run capacitor is housed in a cylindrical or rectangular can on the motor. Look for bulging, leaking, or burnt smell.
• 4. Replace capacitor: If you are competent and local regulations allow, replace the capacitor with an identical µF and voltage rating Davey-approved part. Observe correct wiring.

If the motor still only hums after capacitor replacement, the windings may be damaged and the motor should be replaced.