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AC Not Cooling? How To Check For AC Compressor Failure

Inside of your air conditioning system, there’s a part called the compressor, which is considered the heart of your unit. So, if it fails, your entire air conditioning system will follow suit—and nobody wants that!

Check For A Compressor Failure

Your AC system’s compressor pumps refrigerant through your unit to cool the air in your home. When your compressor stops working, you may notice your air conditioning not working and your home heating up too fast. The sooner you identify if a compressor failure has occurred, the sooner you can cool off.

How To Check For A Compressor Failure

  • Locate the circuit breaker for the outdoor unit in the main electrical panel. If it's in the mid position between on and off, it will need to be reset.

    In most cases, the breaker likely tripped when there was a brief power interruption and just needs to be reset. However, if a capacitor failed causing a higher electrical current through the circuit breaker or if the compressor is developing a lubrication or internal electrical problem, it may trip again.

    To reset the breaker, push it firmly to the off position, then on. Only do this once. If the breaker trips again, or will not reset, then something has gone wrong that will require a professional to fix. Call in a technician to diagnose the issue.

  • Listen to your cooling system as it runs. Changes in the sound can indicate what's wrong. A condenser that's too loud can indicate an airflow issue, dirty coils, or a mechanical defect with the compressor. A condenser that's too quiet could mean there is a partial loss of refrigerant or the compressor may not be running at all even though the outdoor fan spins.

  • When your HVAC system is working normally, the temperature should match the setpoint on the thermostat. If the temperature in the house begins to stray more than two degrees from the setpoint for extended periods of time, there may be an issue affecting the system's performance.

  • Use a thermometer to measure the temperature coming out of the vents while your AC is running. A properly operating cooling system will deliver air from the supply vents that is 16–22 degrees cooler than the air around the thermostat. If the air temperature coming from the vents isn't within range after at least 15 minutes of running your AC continuously, it may be time to place a service call to address the issue.

  • Be sure all of the air registers are open and unobstructed. If there's furniture overtop of the register, move it away so that the air can flow freely. Next, check the system's filter. If you have a central air system, the filter is usually located next to your furnace or air handler, but may occasionally be in the return vents just behind the grill. If you have a mini-split system, the filters are under the cover of each inside unit. Once you've found the filter, make sure it's clean and free of debris.

    After checking the inside airflow, check the outside condenser as well. Clear away any leaves, debris, or blockages from around the condenser.

    CAUTION: Make sure to turn off your central AC or mini-split system before pulling the filter out.

Is your compressor working properly? Consider other reasons for why your AC is acting up.

What To Do If You Have A Compressor Failure

Once you’ve determined you’re dealing with an AC compressor failure, you’ll want to call an HVAC professional to repair the issue and get your air conditioning back to cooling!

If you’d like a helping hand in the troubleshooting process, one of our Remote Assist Experts can guide and help you identify the next steps towards a working AC system.

NOTE: This content is for informational purposes only, and HomeX and its affiliates disclaim all liability related to it. If you decide to perform any tasks based on this information, you assume all risks, including the risk of loss or damage to property or personal injury.

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