3 Common Reasons Why Your Air Conditioner Is Blowing Warm Air

Air Conditioner with Remote Control
Air Conditioner with Remote Control
If your air conditioner is running, but the air coming from the vents isn't cold, you may be afraid that something terrible has happened to your system. However, you should know that the lack of cold air isn't always a major problem.

The truth is there are common, less-catastrophic causes of this type of problem. With that in mind, below are three common reasons why your central air conditioning system is not producing cold air.

1. The Thermostat Is Set Incorrectly
One of the most common causes for an air conditioner failing to provide cool air is an incorrectly set thermostat. Modern thermostats offer many conveniences, but they can be confusing to use if you aren't familiar with their operation.

As an example, thermostats contain controls that inform the system fan when it will operate. There is an automatic operation setting, labeled "auto" and another for continuous operation labeled "fan" or sometimes simply "on."

If the fan setting is "fan" or "on," then the air conditioner will blow air continuously regardless of whether or not the compressor is running. This means that circulating air may or may not be cool and may lead you to believe the unit isn't functioning properly. For most homeowners, the "auto" setting is best because the fan will only run when the unit is in cooling mode.

That is why it’s important for homeowners to familiarize themselves with the thermostat user guide and understand how the controls change various operating modes. By taking a few minutes to read the instructions, you may be able to eliminate frustration and possibly even an unnecessary service call.

2. There’s No Power Available to the Outside Unit

Another reason why your air conditioner is producing warm air is a lack of power to the outdoor unit. The outdoor unit contains the compressor, condenser coil and a fan that helps disperse heat from the system.

If there is no power available to the outdoor unit, the all-important compressor will not be able to pump refrigerant through the system. A lack of refrigerant means that no cooling will occur inside the indoor unit. The indoor fan will continue to circulate air through the ducts, but it will be uncooled.

A disconnected circuit is one of the most likely reasons the outdoor unit is without power. Outdoor units are connected to an electrical panel located on the nearest exterior wall, and they contain a master switch that can be turned off for service reasons. Should you discover this switch has been turned off, simply push the handle back into the “on” position to restore power.

3. The Coils Are Dirty or Frozen

Dirt or ice on your evaporator or condenser coils can prevent your air conditioner from blowing cold air. These coils are interchange points where heat is transferred from your home to the outside and released. If the coils become covered with debris or freeze over, the heat cannot enter the refrigerant in the evaporator nor can it escape the condenser.

That’s why it is important to ensure your coils are kept clean of debris and your system's refrigerant level is maintained. Leaves, dirt, sand and plants can block the condenser coil on the outside of your home, while too little refrigerant can result in evaporator coil icing.

In the case of dirty coils, you will need to clean them yourself using a coil cleaning solution or contact a professional air conditioning service company for assistance. If the refrigerant is too low in the system, a qualified technician will need to perform a recharge of the refrigerant and inspect the evaporator coil to ensure it also doesn't need cleaning.

If you have questions about your air conditioning system or aren't sure what to do when it's not working correctly, be sure to contact the professionals at Total Comfort Heating & Air Conditioning, LLC for assistance. We can help restore your system back to normal and provide ongoing maintenance.