Controller shows E03 / HIGH ENGINE TEMPERATURE and the generator shuts down after running under load.

Safety first: Disable AUTO mode and allow the generator to cool completely. Do not open any coolant caps on a hot engine.

• Inspect airflow: Check that the Winco enclosure louvers and intake/exhaust vents are not blocked by debris, snow, leaves, or stored items. Clear at least 3 feet of space around ventilation openings.
• Clean cooling fins: On air-cooled Winco engines, remove the side panels per the manual and blow out dust and debris from the cylinder cooling fins and flywheel fan using low-pressure compressed air.
• Check coolant level (liquid-cooled): When cool, remove the radiator cap and verify coolant is at the proper level. Top up with the recommended coolant mixture. Inspect hoses and the radiator for leaks.
• Verify fan operation: Start the unit in MANUAL with no load and confirm the cooling fan runs and pulls air through the radiator or shroud. If the fan does not run, check the fan relay, fuse, and wiring.
• Inspect temperature sensor: Locate the engine temperature sensor on the cylinder head or coolant passage. Check for loose connectors or damaged wiring.

If the generator continues to overheat after cleaning and verifying coolant and fan operation, stop using it and have a technician check for internal engine or cooling system faults.