What should I do if the air conditioner doesn't cool properly?

First, check that airflow is not restricted by curtains, blinds, furniture or obstacles in front of the unit. Turn the thermostat knob to a higher setting for maximum cooling. Clean the filter at least every 2 weeks, and note that after turning on the unit, allow time for it to cool the room. If ice appears on the cooling coils, set the fan to MED or HIGH and the thermostat to 1 or 2 until the ice melts.