Indoor unit runs but does not cool effectively; air is only slightly cool or room never reaches set temperature

Safety first: Turn off power before cleaning coils or filters.

Steps:

• Clean filters: Remove and wash indoor air filters with mild detergent. Dry completely before reinstalling.
• Clean coils: Gently clean the indoor evaporator and outdoor condenser coils with a soft brush or coil cleaner to restore heat transfer.
• Check airflow: Ensure supply and return vents are not blocked by furniture or curtains. Verify louvers are directed appropriately.
• Check setpoint and mode: Confirm the unit is in Cool mode with a set temperature at least 3–5°C below room temperature and that Fan Only mode is not selected.
• Technician check: If performance is still poor, a technician should check refrigerant charge, system pressures, and confirm the unit is correctly sized for the space.