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

Safety first: Turn off power at the breaker. Do not keep resetting the breaker as this can overheat wiring.

• Check for impeller obstruction: Remove the pump lid and basket, then attempt to rotate the impeller by hand. If jammed, clear debris or disassemble the wet end to access the impeller.
• Test motor shaft: At the rear of the motor, try to spin the shaft or fan by hand. If stiff or seized, the bearings are likely failed and the motor needs overhaul or replacement.
• Inspect start capacitor: Many AstralPool single-speed pumps have an external capacitor under a small cover on the motor. If it is bulged, cracked or leaking oil, it should be replaced with an identical rated part by a qualified person.