Pump attempts to start, hums briefly, then stops and displays F3.

Safety: Turn off power at the main switchboard and verify the pump cannot start unexpectedly.

• Check for mechanical jam: Remove the pump lid and basket. With power OFF, insert a screwdriver into the impeller eye (without damaging blades) or turn the motor shaft from the rear fan cover. It should rotate smoothly. If it is stiff or seized, the impeller or bearings may be jammed.
• Inspect for debris: Shine a torch into the volute and impeller area. Remove any stones, twigs, or cable ties that may be wedged in the impeller.
• Check wiring at terminal box: If you are competent and local regulations allow, remove the motor terminal cover and inspect for burnt or loose wires. Tighten terminal screws gently. If any insulation is burnt, stop and call a technician.
• Try a restart: Reassemble the pump, restore power, and start the pump. If F3 reappears immediately, do not keep retrying.

Persistent F3 usually indicates a failing Hurlcon motor or seized bearings and requires motor or complete pump replacement by a qualified technician.