Safety: Unplug the unit. Moving fan blades can cause injury; ensure the fan cannot start unexpectedly.

Steps:

Clean filters and vents: Remove and wash the air filter. Ensure intake and exhaust vents are clear of obstructions and that the exhaust hose (for portables) is not kinked.
Check indoor fan operation: With the unit reassembled and powered, run in fan-only mode. If the fan does not start or is very weak, suspect the indoor blower motor or capacitor.
Inspect blower wheel: Disconnect power, remove the front cover, and spin the blower wheel by hand. It should rotate freely without scraping.
Test fan motor: Measure resistance of the fan motor windings and check for continuity to ground. Replace the motor if windings are open or shorted.
Check control board temperature: Ensure the main control PCB is not enclosed by insulation or blocked from airflow; overheating can trigger E8.
Replace faulty parts: Install a new indoor fan motor or fan capacitor as needed. If all mechanical parts are good, the main control PCB may be misreading overload and require replacement.

Unit shuts down and displays E8; may be accompanied by very low airflow or icing.

Possible Causes