5 Reasons Your AC is Blowing Warm Air | Efficient AC, Electric & Plumbing

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AC Repair FAQ: Why is My AC Not Cooling?

When an air conditioner is blowing warm air, it may run longer and fail to adequately cool your home in the Austin, Texas heat. There may be poor airflow and/or poor heat transfer resulting from one or more of the following AC repair issues.

5 Reasons Your Air Conditioner is Blowing Warm Air or Not Cooling

  1. Dirty/clogged air filters – Dirty or clogged air filters will impede airflow. This significantly reduces the transfer of heat (moisture) from the air to the coils, which can lead to the coil icing or freezing up, significantly longer run times and little to no change in temperature. Replace filters regularly as recommended based on the environment and the type of filter you have installed.
  2. Dirty/clogged coils – This may be either the indoor or outdoor coil, but if you are replacing your air filters on a regular basis, the most common cause is a dirty outdoor coil. Though the coil may look physically clean, dirt and debris get trapped in between the fins of the coil, which reduces the ability of the coil to dissipate the heat from the coil/system. This can lead to coil icing (freezing) and/or longer run times. A qualified service technician can check the system and determine if this is the cause. Only a properly trained AC repair technician should ever clean these coils. PLEASE BE AWARE: You should never attempt to clean these yourself. High voltage is present and there is significant risk for injury or death if this cleaning is not done properly.
  3. Clogged condensate drains – The unit may have a tripped float switch (water safety switch). Float switches are used to minimize water damage in the case of a clogged condensate drain or leaking (frozen) evaporator coils. Most residential systems are wired to allow the indoor fan (blower) to continue to run, but the float switch will shut off the condensing unit (outdoor unit) to prevent the system from producing water (condensation). This preventative measure helps minimize water damage caused by clogged drains or overflowing drain pans. As the blower continues to run, the frozen coil thaws, allowing the AC repair technician to make an accurate diagnosis.

    In commercial applications, when multiple systems are used in the same space, it is more common to connect the float switch (water safety switch) in a way that will shut down both the outdoor and the indoor unit. The entire system stops at once.  Wiring the water safety switch in this manner is far less common in residential applications.
  4. Low refrigerant (freon/puron) – This is usually the least common problem, but it may be the first thing homeowners assume when the unit is running but not cooling. Low refrigerant reduces the temperature of the evaporator coil (indoor coil) and will cause the unit to run longer, stop cooling efficiently and/or ice up (freeze) due to insufficient heat transfer. A qualified service technician can properly assess the system, determine if the unit has the correct refrigerant charge and adjust as needed.
  5. Defective condensing fan motor, capacitor or compressor – One of several components in the outdoor unit may have failed. A fan motor or run capacitor is often the cause, but the compressor could also be defective. A fan motor or capacitor is generally a minor repair that is reasonably affordable, especially on newer equipment less than 12 years of age.

    A compressor failure, on the other hand, can be quite costly – almost as much as the entire outdoor unit in some cases. If the system is older than 12 years of age and the compressor has failed, our AC repair specialists usually recommend looking into replacement options for the entire system. The energy savings and reliability of a newer, more efficient system will offset some of the cost difference between the compressor repair and complete AC replacement. In addition, most new systems come with a 10-year compressor warranty, while a compressor only carries a one-year warranty when repaired separately.

If your AC is not cooling, please get in touch. Our service area covers all of Austin metro, including Round Rock, Cedar Park, Georgetown, Pflugerville, Kyle, San Marcos and in between/beyond. We’re here to help you get back to being comfortable as soon as possible.

See for yourself why Austinites have trusted us since 1976.