Controller displays E04 and pump shuts down; may occur during hot weather or long run cycles.

Safety first: Turn off power at the breaker before removing any control covers.

• Improve ventilation: Ensure the AquaFlo control module has adequate airflow. Remove obstructions around the housing and open any louvers or vents in the equipment box.
• Provide shade: If the controller is in direct sunlight, install a UV-resistant shade or cover that does not block ventilation. Avoid wrapping the unit in insulating materials.
• Inspect for dust and debris: Remove the control cover and gently blow out dust from the control PCB and heat sink using dry compressed air. Do not use water or cleaners.
• Check mounting surface temperature: If the pump is installed in a small, unventilated shed, add vents or a small fan to reduce ambient temperature.
• Reset and monitor: After cooling for 30–60 minutes, restore power and monitor operation. If E04 recurs quickly, the internal temperature sensor or control board may be faulty and require replacement.