P4 code; indoor unit may stop and louver may close

This repair may involve working with high voltage components or water connections. Always unplug the appliance before removing any panels.

If you are not confident in your ability to perform this repair safely, we strongly recommend contacting a professional technician.

Possible Causes

Blocked air filters, Extremely dirty indoor coil, Indoor fan failure, Operation in high ambient with restricted airflow

Safety first: Disconnect power before cleaning.

Clean filters: Remove and wash the indoor filters thoroughly.
Clean coil: Use a coil cleaner or mild detergent and water to clean the evaporator fins.
Check fan operation: Ensure the indoor fan runs at all speeds and delivers strong airflow.
Remove obstructions: Keep curtains, furniture, and covers away from the air inlet and outlet.

If P4 continues after restoring airflow, the indoor coil sensor or PCB may be faulty and require service.

Medium 3/5

Indoor Evaporator Coil

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