Pump trips to E02 shortly after starting, motor hums then stops

Safety first: Turn off the breaker and lock it out. Confirm the pump cannot start unexpectedly.

• Check for hydraulic blockage: Close isolation valves, remove the pump lid, and inspect the strainer basket and suction port. Clear leaves, stones, or debris. Spin the impeller by hand (from the motor end if accessible) to feel for binding.
• Inspect impeller and diffuser: If comfortable, remove the motor from the pump housing following the Lowara service manual. Check for debris wrapped around the impeller or damage to the diffuser causing rubbing.
• Check motor rotation: With the pump separated and power OFF, rotate the motor shaft by hand. It should turn smoothly. Any grinding or stiffness indicates failing bearings.
• Electrical checks: Verify supply voltage and phase balance (for three-phase Lowara pumps). Incorrect wiring or missing phase can cause high current draw.
• Reset and test: Reassemble, restore water prime, and restart. If E02 persists with free-spinning impeller and correct voltage, the motor windings may be partially shorted.
• When to call a pro: Overcurrent faults that persist after clearing blockages usually require motor testing with a megohmmeter and ammeter. A technician may recommend replacing the motor or complete pump unit.