Determine if it is producing cold air
Cold Fan Coil + Strong Airflow = Cool Air
When your air conditioner is not cold, it can either be that your Fan Coil is not cold or the airflow is weak or both.
Therefore, it is important for you to know if it will be a repair job or merely a servicing job, or both.
Systematic Troubleshooting :
Turn on the air conditioner and make sure it is set to the cool mode. Set the temperature to the minimum and wait for approximately 3 minutes, the compressor should be running by now.
Climb higher so that you can put your hand very near the aircon blower outlet. The outlet temperature should measure about 16’C when the room temperature is about 28’C. As the room cools down further, for example, to 25’C, the blower output temperature can be as cool as 12’C. If possible, use a thermometer. With bare hands, you may not be able tell 25’c from 28’c , but i think you should be able to tell that difference between a 16’C from a 28’C, right?
How does the wind feels like to you?