• Always check to make sure the units display is not showing the empty tank symbol.  
• If empty tank symbol is showing drain the unit.      
• Check the settings and make sure the room temp is warmer then what the unit is set at.   
• Check that the exhaust hose is connected to the unit properly and make sure there are no kinks or bends in the hose.        
• Check that the filters are clean and free of dust and debris.