Pump stops and displays E03 after running for several minutes, housing feels very hot

Safety first: Allow the pump to cool before touching the motor. Turn off power at the breaker.

• Check water flow and prime: Ensure the pump strainer pot is full of water and that suction valves are open. Re-prime the Lowara pump according to the manual (fill strainer housing, bleed air, then start).
• Inspect motor cooling: Remove debris, leaves, or cobwebs from the motor fan cover and cooling fins. Ensure at least the manufacturer’s recommended clearance around the motor for airflow.
• Verify installation environment: If the pump is in a closed plant room, improve ventilation or add louvered vents. Excessive ambient heat can trigger E03.
• Check for mechanical drag: With power OFF, rotate the motor shaft by hand. Roughness or stiffness indicates bearing wear, which causes overheating.
• Reset and monitor: After cooling, reset the drive or thermal protector and restart. Monitor current draw and temperature. If E03 recurs quickly, the motor may be failing.
• When to call a pro: Persistent overtemperature faults require motor current and insulation tests. A technician may replace the motor or complete Lowara pump assembly.