Discovering that your air conditioner doesn't work during one of the hottest days of the summer is probably one of the worst things you could experience. Unfortunately, it's not all that uncommon. Luckily, you can help speed up the repair process by knowing the reasons why it might have failed.

So why might an air conditioner stop working? Here are three common reasons:

1. Thermostat Stetting

One of the most common reasons for an air conditioner to stop working properly is due to the thermostat. Often times, the thermostat is adjusted during the off season. If not double-checked, it's possible that your thermostat is set to the fan setting. It's also possible that it isn't adjusted to a cool temperature. So before calling a professional, make sure the thermostat is set to "cool" and that the temperature is cool enough to feel a difference.

If your thermostat is set properly, there might also be an issue with the thermostat itself. It might not be reading and registering temperatures correctly. Unfortunately, this will require you to replace the thermostat.

2. Obstructions

Another reason you might not be feeling the cooling of your air conditioner is due to obstructions. The main culprit in this scenario is a blocked condenser. Located outside your home, the condenser plays a large role in your air conditioning unit. Since this important part is located outside, it's possible for it to become blocked by dirt and debris. It could also be blocked by tree branches, plants, or other material. So you might want to head outside and take a look. If there are items located on the outside part of the unit, clear them and see if that helps.

3. Ductwork Issues

A damaged or broken duct might also be to blame for your hot indoor temperatures. Since the ducts are responsible for carrying the cool air to your home, they must be in good condition. If they are cracked or damaged, you won't feel the cool air because it will escape before it reaches your room. Unfortunately, this is an issue that requires the help of a professional, as identifying and fixing ductwork is often difficult for the average homeowner.

While there are many possible reasons for your air conditioner to not work properly, these three are the most common. If you have attempted to fix the problem yourself without much luck, don't worry. These problems are fairly easy for an air conditioning repair professional to fix. However, make sure you address the problem quickly; as the problem may quickly escalate into a bigger problem if left untreated.