Why Is My AC Not Blowing Cold Air?

Our Expert Advice

the most common reasons your air conditioner might not be blowing cold air could be due to a blocked exterior unit, a malfunctioning thermostat, or an electrical issue. These problems can restrict airflow, prevent the system from turning on, or disrupt power supply to the unit. It’s important to check for any obstructions around the AC unit, ensure the thermostat is functioning correctly, and inspect for any tripped breakers or blown fuses.

Jump to Some Common Issues

Why Is My AC Not Blowing Cold Air?

An air conditioner that is not blowing cold air can be a big problem. Especially if it happens on a scorching summer day. There are many reasons why an air conditioner may not be working as expected. Thankfully some of these reasons are a quick fix that you can do on your own. Here is a list of some reasons why your air conditioner may not be blowing cold air that you can check on your own and what you can do to fix it.

  1. It’s being blocked – When your air conditioner is blocked by exterior debris it will not be able to function properly. When you first notice that your ac is not blowing cold air your should go outside and take a look at the exterior of the unit. Make sure nothing is stuck to the outside of the unit. Remove anything that may be blocking airflow to the air conditioner. As a good preventative measure it is important to do regular cleaning of the area around your AC unit. Check our air conditioner maintenance checklist to ensure you stay on top air conditioner maintenance This is one of the most common reasons why an air conditioner may not be blowing cold air.
  2. Your thermostat isn’t working correctly – Make sure your thermostat is turned on and is on the correct setting. Additionally, if there is a problem with your thermostat it may prevent your air conditioner from turning on and off when it needs to. It is important to ensure that you have your thermostat installed correctly by a professional. Get your thermostat checked if you feel it may be the cause of your air conditioner problems.
  3. You have an electrical problem – adequate power may not be making its way to your air conditioning unit. Make sure you haven’t blown a fuse, or any other electrical issues related to your unit. You may not be able to fix all electrical problems on your own, but starting with resetting your breaker may be a good start.
  4. Refrigerant Leak – The refrigerant is the substance that your air conditioner uses to remove heat and humidity from the air in your home or business. If your system develops leaks in the refrigerant lines, you can end up with not enough refrigerant to effectively cool the air. Unfortunately, fixing this issue is not as simple as adding more refrigerant. An HVAC technician needs to find and repair the leak, which can be time-consuming and costly. After the repair, they will test the repair and charge the system with the correct amount of refrigerant. Remember that the performance and efficiency of your air conditioner are greatest when the refrigerant charge exactly matches the manufacturer’s specification, and is neither undercharged nor overcharged.
  5. Dirty Evaporator Coils – Your air conditioner’s evaporator coil is filled with refrigerant and is responsible for absorbing the heat from the air like a sponge. Over time, these coils can become dirty. Dirty coils prevent effective heat transfer and can significantly decrease the ability of your air conditioner to cool the air. To fix this issue, you need to clean the coils. This can be done using a soft brush and coil cleaner, which are available at most hardware stores. Be sure to follow the instructions for the cleaner, and be careful not to bend or damage the coils while cleaning. It’s also a good idea to have your evaporator coil checked and cleaned annually by a professional as part of regular AC maintenance.
  6. Faulty Compressor – The compressor is the heart of your air conditioner’s refrigeration cycle. If the compressor is not working, the AC unit will not cool your house. If the compressor is not running but you hear humming noises, it might be trying to start but failing. This could be due to a capacitor problem, or the compressor itself might be at fault. Replacing a compressor can be quite costly and often requires the expertise of a certified technician. In some cases, if the compressor is under warranty, it might be more cost-effective to replace the entire outside unit. Always consult with a professional to determine the most cost-effective and efficient solution.

What if it’s still not working?

If you have done a check of your ac’s exterior, filter, thermostat, and breaker and the problem has not been resolved it is likely time to call a technician. A technician will be able to service your air conditioner and diagnose the issues that are stopping it from working. The suggestions listed in this article offer good first steps for self diagnosing the issues but do not replace the knowledge of a professional.