Emaux variable-speed pump stops during operation and shows E03, often after running for several minutes.

Safety first: Turn off power at the breaker before touching the motor housing; it may be very hot.

• Check water flow: Ensure the suction and return valves are fully open. Confirm the pool water level is above the skimmer opening so the pump is not sucking air. Prime the pump by filling the strainer housing with water and restarting.
• Inspect ventilation: Clear leaves, plastic, or debris from the motor cooling fins and fan cover. Ensure there is at least 30 cm of free space around the motor for airflow.
• Verify pump is not running dry: If the pump basket does not stay full of water within 30–60 seconds of starting, shut it down and check for suction-side blockages or air leaks.
• Allow cooling time: Let the motor cool for 30–60 minutes before restarting. Do not cover the motor or place it in a sealed box without proper ventilation.

If E03 recurs frequently under normal load and good ventilation, the internal thermal sensor or motor windings may be failing and the motor assembly should be evaluated by a service technician.