Why my air-conditioner is not working?

Lack of maintenance
The most common problem is lack of maintenance. An aircon is like a kidney, you do not know there is a problem until there is one. This is why regular servicing is paramount. A domestic aircon should be serviced annually, while a commercial aircon needs to be maintained every six months.

Check outside unit
Over time, it is easy for leaves, grass clipping, and other debris to build up on the outside of the air conditioning unit. This may not seem like a big deal, but the truth is that it can lead to further maintenance issues over time. For this reason, it is a good idea to clean off the AC unit every so often when you begin to notice this buildup.
Don’t Lose Your Cool — Call Pwl Air Conditioning!
"When things heat up, especially in your home. You know it’s time to call Pwl Air-conditioning and let us bear a hand with AC repair or AC installation."