Portable or window Haier AC shows P3 and may stop or run at reduced capacity.

Safety first: Unplug the unit before cleaning or inspection.

• Clear airflow: Ensure there is at least the recommended clearance around the unit and that curtains or furniture are not blocking vents.
• Clean filters: Remove and wash the air filters. Let them dry completely before reinstalling.
• Check fan operation: Plug in and run the unit. Confirm that the fan blows strongly. If airflow is weak, the fan motor may be failing.
• If P3 continues: Internal sensors or control board may be faulty and should be checked by a service technician.