Diagnosis
The unit is likely in fan-only mode, or the exhaust hose is not properly configured. Check the Mode setting on the control panel.
How to Fix It
First, verify the Mode is set to Cool, not Fan. Confirm the blue exhaust hose is fully extended and connected tightly at both the unit and window bracket. Ensure the window seal kit is installed correctly, with no large gaps. The unit must vent hot air outside to cool.
If That Didn't Work
The unit may be low on refrigerant due to a leak. This is a sealed system issue requiring a certified technician. Listen for a hissing sound near the hose connections as a potential leak indicator.
Heads Up
In high ambient heat, the compressor may cycle off. If the room temperature is within 2-3 degrees of your set temperature, the unit will run the fan only, making the air feel warm.