Diagnosis
Your unit is running but the refrigerant isn't cooling. The most common cause is incorrect exhaust hose setup or a kinked hose.
How to Fix It
Check the two hoses first. Ensure the smaller, insulated hose is the INTAKE and connects to the window kit. The larger, uninsulated hose is the EXHAUST. They must be fully extended (no kinks) and pushed firmly into the window seal. A swapped or pinched hose creates a short circuit where hot air gets pulled right back in.
If That Didn't Work
If hoses are correct, the unit may be low on refrigerant due to a leak. Listen for a faint hissing sound near the hose connections when running. A refrigerant leak requires a professional technician to repair and recharge the system.
Heads Up
This unit cools a single room, not an open floor plan. Close all other doors and windows. The advertised BTU rating assumes a sealed space.