When your air conditioner starts blowing room-temperature air, there are several different reasons why this could be happening. While some causes are related to component failure, many fixes are relatively simple and inexpensive, especially with the help of a professional.

Fuses Need Replacing

An air conditioner's fuses are designed to take the brunt of any electrical damage, such as a surge. Since they're relatively inexpensive, it's easier to replace them if they fail than a much more expensive component.

If you hear a humming sound from your outdoor unit while room-temperature air comes from your vents, but the outdoor fan isn't moving, the fuses may have failed, leaving your air conditioner without enough power to run. Once they are safely replaced, try running your air conditioner again.

Start Capacitor has Failed

Another component that can sometimes fail is the start capacitor. This is the component responsible for providing the surge of power necessary to get the fan blades in your air conditioning unit moving. When this fails, even if your air conditioner is receiving power, it won't be able to actually start.

When this part fails, you may also hear humming from your outdoor unit when the air conditioner is supposed to be running, but nothing will be moving. If your fuses are in good shape but you still have this problem, contact local air conditioning services for assistance.

Clogged Air Filter

Your air conditioning system has several automatic safety functions that cause the air conditioner to shut down if it is at risk of overheating. One thing that can cause your air conditioner to overheat is a lack of airflow. This can happen if your air filter hasn't been replaced in a long time; dust, dirt, and other contaminants build up on the filter, restricting airflow and causing your air conditioner to have to work harder to cool the same amount of air. If the airflow is restricted too much, your air conditioner may shut itself down.

In this case, the fix is simply replacing your old air filter with a new one. How often you should replace your filter depends on a variety of factors, such as where you live, if you have pets, and the material your filters are made of. Stick to a regular schedule of replacing your air filters to ensure your air conditioner doesn't wear itself down too quickly.

Clogged Condensate Drain

As your air conditioner cools the air, it pulls moisture out of it, and this moisture is drained out of your house. If this drain clogs for any reason, this also triggers the automatic shutoff function of your air conditioner to prevent your home from experiencing any water damage.

If your air filter is clean but you still experience this problem, locate your condensate drain and make sure it can drain properly. If you suspect it may be clogged and you aren't able to fix it yourself, contact a technician for help.