Safety: Disconnect power before removing the indoor unit front cover. The fan wheel can start unexpectedly if power is present.

Steps:

Filter and blower cleaning: Remove and clean air filters. Inspect the cross-flow fan (drum) for heavy dust buildup. Clean carefully with a soft brush and vacuum.
Check for obstructions: Look for foreign objects inside the air outlet or near the fan wheel that could block rotation.
Spin test: With power off, rotate the fan wheel by hand. It should spin freely without scraping. If stiff, the motor bearings may be failing.
Electrical check: Verify the fan motor connector is fully seated on the indoor PCB and that wires are not damaged.
Test run: Restore power and run the unit at different fan speeds. If E8 returns and the fan does not reach commanded speed, replace the indoor fan motor assembly.
PCB check: If a new motor does not fix the issue, the indoor PCB may not be providing correct drive voltage and should be tested by a technician.

Indoor unit displays E8; unit may stop unexpectedly, especially in high load conditions.

Possible Causes