Air conditioner runs but does not cool the room effectively; air from vents is only slightly cool.

Safety: Turn off power before cleaning coils or removing covers.

Steps:

• Check thermostat setting: Ensure the mode is set to COOL and the set temperature is at least 3–5°C below room temperature.
• Clean filter: Remove and clean the air filter thoroughly.
• Clean indoor coil: With the front panel removed, gently vacuum the evaporator fins. Use a coil cleaner approved for aluminum fins if heavily soiled.
• Clean outdoor coil: Remove debris and wash the condenser coil with low-pressure water, avoiding the control box.
• Check fan speeds: Ensure the indoor fan is set to HIGH for maximum cooling.
• Room size check: Compare the unit's BTU rating to the room size; if the room is too large, the unit may never reach setpoint.
• Professional check: If performance is still poor, have a technician check refrigerant charge and system pressures.