Display shows E9 and unit stops; may occur during heating or dehumidifying modes on some models.

Safety: Turn off and unplug the unit. Exhaust components may be hot.

• Check exhaust hose (portable units): Ensure the hose is not kinked, crushed, or excessively long. Remove any obstructions at the window kit or wall outlet.
• Inspect exhaust outlet: Verify that louvers or flaps at the exhaust outlet move freely and are not stuck closed.
• Locate exhaust sensor: Access the exhaust duct area inside the unit and locate the thermistor or thermal sensor attached to the exhaust path.
• Check sensor mounting: Ensure the sensor is properly positioned and not hanging loose away from the exhaust surface.
• Test sensor: With a multimeter, measure resistance at room temperature and compare to other thermistors in the unit. Replace the exhaust temperature sensor if readings are open/shorted or far out of range.
• Airflow verification: After clearing obstructions and replacing any faulty sensor, reassemble and test. If E9 persists with good airflow, the main control PCB may be misreading the sensor and require replacement.