Why Is My AC Not Blowing Cold Air?

If your AC unit is failing to blow out cold air, it could be the result of the following 9 items.

Reasons Why AC Is Not Blowing Cold Air

Air conditioners work by compressing a fluid refrigerant, which causes it to move between two different sets of metal coils. Air is drawn across the cold coils and then move back into the home’s interior via a series of dampers and ducts. Temperature is set at the thermostat and regulated by the corresponding control board.

Most homes feature a split-unit central AC system, which means the evaporator coil is inside the home, with the condenser unit and compressor located outside. Let’s now take a look at some reasons why your AC is not blowing out cold air.

1. Power

It’s recommended to start with the simplest troubleshooting steps whenever your AC isn’t working properly. Begin by confirming that the AC is getting power.

Do this by checking three locations: the circuit breaker at the panel, the furnace or heat pump’s power switch, and the exterior unit’s disconnect. Of course, the power switch can be inadvertently turned off, so switching the power back on can be an easy fix.

2. Ductwork Trunk

If the fan is running and the filter appears clear, feel the ductwork trunk, which is found just past the blower. If the trunk feels cold, there could be something disturbing the air flow further down the line. Now is the time to troubleshoot the ducts.

3. Ductwork Dampers

Many homes will feature dampers in the ductwork. These allow you to force air to certain areas of the home that need it more, dependent on the season. If the dampers happen to be out of alignment, then they can act as roadblocks preventing cold air from getting to where it needs to be. Damaged or leaky ducts can pose similar problems.

4. Air Flow

In a central AC unit, nothing causes more issues than air flow. The good news is air flow is the easiest repair to complete. Start by checking the furnace to see if your furnace filter needs to be replaced.

Dirty filters will prevent air from crossing the evaporator coils, meaning the cooling power sits inside the AC unit and never disperses throughout the home. Change the filter regularly for your AC to work efficiently.

5. Vents

The majority of rooms inside your home will feature adjustable vents. Ensure these vents are not obstructed or covered. Take a look inside using a flashlight to determine if the dust build-up needs a full air duct cleaning.

6. Condenser Coils

Central AC units move heat from inside the home to outside. If the condenser coils are obstructed by any object, though, heat will not escape efficiently. This causes your unit to work intermittently, with short bursts of lukewarm air emerging. Clean the AC condenser to fix this issue.

7. Evaporator Coils

When excess water is dripping off the AC cabinet or ice is forming around the refrigerant line, it means your evaporator coils are producing ice that interferes with the air flow. Troubleshoot this problem by turning the AC off for 24 hours and set your fan to ON or FAN ONLY. This will allow warm air to run over the coils. You may have a refrigerant problem if ice reappears after you restart the system.

8. Compressor And Refrigerant

More complex issues with the compressor and refrigerant are often too much for DIY fixes. If your refrigerant level is low, it’s likely the result of a leak. Any refill is temporary at this point.

Check your unit to see what type of refrigerant it uses and keep that in mind when getting repair quotes. If you have an older freon-based unit, it may be time for a full replacement.

9. Capacitor

The capacitor may need to be replaced if the exterior unit is not kicking on. This is only a DIY repair if you are extremely comfortable with electronics.