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Excellence A/C & Heating LLC
Excellence A/C & Heating LLC

Frequently Asked Questions on HVAC Service: Why is My Air Conditioner Not Cooling?

5 reasons air conditioners blow warm air or don't cool (air conditioning maintenance).

Air filter dirty/blocked - Air filter dirty or blocked can block airflow. This significantly reduces the transfer of heat (moisture) from the air to the coil, which can cause the coil to freeze or freeze, significantly lengthening the running time and with little change in temperature. Replace filters periodically as recommended, depending on the environment and the type of filter you install.  

Installing Uncased Evaporator Coil

Coil dirty/blocked - This can be an indoor coil or outdoor coil, but if you change your air filter regularly, the most common reason is that the outdoor coil is dirty. Although the coils look clean, dirt and debris can get trapped between the coils' fins, which reduces the coils' ability to dissipate heat from the coils/system. This can cause the coil to freeze (freeze) and/or longer running times. A qualified maintenance technician can check the system and determine if this is the cause. Only properly trained air conditioning technicians should clean these coils. Please note: you should not try to clean these yourself. High pressure is present and there is an obvious risk of injury or death if cleaning is not done correctly.  

The condensate drain is blocked - the unit may have a tripping float switch (water safety switch). The float switch is used to minimize water damage in the event of a blocked condensate drain or a leaky (frozen) evaporator coil. The wiring of most residential systems allows the indoor fans (blowers) to continue operating, but the float switch will turn off the condensation unit (outdoor units) to prevent the system from producing water (condensation). This precaution helps minimize water damage caused by blocked drains or overflowing drain pans. As the blower continues to operate, the frozen coils are thawed, enabling ac maintenance technicians to make accurate diagnoses.  

Commercial Heating And Air Conditioning Service

In commercial applications, when multiple systems are used in the same space, it is more common to connect float switches (water safety switches) to shut down both outdoor and indoor units. The entire system stops immediately. In residential applications, it is much less likely that water safety switches are connected in this way.  

Low refrigerant (CFC-11) This is usually the least common problem, but it may be the first thing that comes to the mind of a homeowner when the equipment is running but not cooled. Low refrigerant reduces the temperature of evaporator coils (indoor coils) and can cause equipment to run longer, stop effective cooling, and/or freeze (freeze) due to insufficient heat transfer. Qualified maintenance technicians can correctly evaluate the system, determine whether the equipment has the correct refrigerant charge, and adjust it as needed.  

Defective condenser fan motor, capacitor, or compressor - one of several components in the outdoor unit may fail. Fan motors or running capacitors are usually the cause, but the compressor may also be defective. Fan motors or capacitors are usually affordable for minor repairs, especially on newer equipment under 12 years old.