3 Reasons Your Air Conditioner Won't Cool Your Home

If your air conditioner is still blowing air but isn't cooling your home, a relatively simple cause may lie behind the problem. Below are three common, and easily fixed, causes for an air conditioner to stop providing cool air for your home.

Incorrect Settings on Thermostat

A frequent reason why air conditioners may blow uncooled air is an error in setting the thermostat.

One of the most common setting mistakes is to place the system in constant fan mode. While in constant fan mode, a central air conditioning system will continuously operate the squirrel cage fan located inside the air handler. The fan pushes out air regardless of whether the compressor is pumping refrigerant through the evaporator coil, which is how the air conditioner chills the surrounding airflow.

Resolving this problem is simple. All you need to do is change the system setting to automatic mode. When the system is set to "auto," the fan will only operate if the cooling function is activated. That means the air you feel will be cooled, and once the desired temperature is met, the system will simultaneously cut off the fan and compressor.

Dirty Evaporator or Condenser Coils

Another reason why your air conditioner isn't putting out cool air is because the evaporator or condenser coils are dirty. As mentioned, the evaporator coil is where cooling takes place. Warm air from inside the home passes over the evaporator coil, which contains refrigerant. The refrigerant then absorbs the heat from the air and passes the cooled air back into the home's interior.

The condenser coil operates in an exactly opposite manner by releasing heat from the refrigerant into the outside atmosphere. This action renews the capability of the refrigerant to absorb heat once more when the refrigerant enters the evaporator coil.

For an air conditioner to cool the air, it must be able to freely absorb and release heat. The critical exchange of heat can't be inhibited at either the evaporator or condenser coils, and even a small layer of dust, dirt, oil or any other debris can insulate the coils. As a result, your air conditioner will still blow air, but it won't be cooled due to the poor heat exchange.

Fortunately, the fix for dirty coils is straightforward: clean them. While homeowners can perform the task if they are careful and use the right tools and materials, it is best to contact an air conditioning service company for help. Professional technicians will understand how to do the job without risking damage to your system or injury to yourself.

Failed Start-Run Capacitor

Another relatively common reason why central air conditioners will often blow uncooled air is a failed start-run capacitor. This small electrical component is housed in the outdoor unit, which also contains the compressor and condenser coil.

The start-run capacitor is important because it provides an electrical "kick" for the compressor and cooling fan. Without the extra burst of electrical energy, these system components will fail to start and run (hence the name).

Start-run capacitors are particularly prone to failure due to the high electrical load they carry and to the constant surge and drain of power. In addition, exposure to the outdoor heat of summer can also contribute to failure.

As with the other problems, the fix isn't complicated and can be handled by a professional air conditioning technician in a short amount of time. It is important that you don't attempt to replace the start-run capacitor yourself because it can provide a nasty or even fatal electrical shock if mishandled.

If you have questions about your home's air conditioning system, or if it isn't cooling as well as you think it should, be sure to contact All American Air & Electric for help. Our friendly team will be glad to diagnose and service your system and get your air conditioner back into shape.