In the United States, over 90% of houses have air conditioning, with many having central air.

If you have central air, you know how wonderful it can make your home feel during the hottest days. Central AC not blowing cold air into your home? Then, you likely have a keen awareness of what it feels like to live inside of an oven.

Let’s take a look at five common problems that could make your central air unit stop blowing cold air.

1. Check the Filter

The first and easiest thing to check is the air filter. If the air filter hasn’t been changed in a while, or if it has become clogged by dirt or pet hair, it could cause the problem. Changing an air filter is cheap and easy. To prevent this problem, make sure you change yours at least once every few months.

If you have multiple pets in the house, or particularly furry pets, you might consider changing the filter every month. This will not only keep the AC blowing cool air, but it will help the unit last longer.

2. Refrigerant Low

One of the most common reasons why you may experience a central AC not blowing cold air is low refrigerant. Without refrigerant, the heat can’t be removed from the air. You should call an HVAC repair technician as handling refrigerant can be dangerous.

Refrigerant leaks are the most common reason behind a central AC not having enough. The chemicals used vaporize, so you won’t notice a wet spot or any leaking. Even a hole the size of a pin can cause your refrigerant to go low.

3. Evaporator Coil or Condenser

If your central AC condenser is not working, you’ll find your AC blowing warm air. If the evaporator coil is not functioning, the same thing will happen. These components are vital for the process of removing heat from the air and circulating it back into your home.

A trained professional can diagnose the problem and perform AC repair for you.

4. Thermostat Problems

Along with the filter, the first thing to check is the thermostat. Make sure it is set right and appears to be working. If it isn’t, then you may need to have it replaced. If possible, turn it off and then on again and see if it starts working.

Getting a new thermostat is a lot cheaper than an AC replacement. Often thermostats get installed in by DIYers who don’t get them installed right.

5. Outdoor Unit and Debris

If your outdoor unit is covered with dirt or debris, you will have a big problem. The heat that gets removed from the inside air transfers out of the house via this unit. If it is covered with dirt or debris, it might not be able to release the heat.