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Air Comfort Systems technician repairing an AC that won't turn on

8 Reasons Why Your AC Won’t Turn On-And What To Do?

When the scorching heat of Austin hits, and your air conditioner fails to turn on, things can quickly become uncomfortable and stuffy. But worry not because Air Comfort Systems is here to provide the much-needed relief to keep you cool, even when your AC doesn’t start properly.

HVAC technician inspecting an unresponsive air conditioning unit

In this article, we will explore eight common reasons why your air conditioner may refuse to turn on and provide you with detailed insights on how to troubleshoot and fix each of these issues. 

With our expert guidance, you’ll be able to regain the refreshing comfort of a fully functional air conditioning system in no time!

1. Check The Thermostat

If your AC isn’t turning on, the most likely culprit is a problem with the thermostat. 

  • First, check that the thermostat is on and set to “cool.” 
  • Ensure the temperature is set a few degrees lower than the normal ambient temperature of your home. 
  • It’s also worth replacing the batteries to rule out any power issues. 
  • If these steps don’t solve the problem, the temperature sensor in the thermostat may be inaccurate. 
  • A faulty thermostat that can’t accurately read the set temperature may prevent your air conditioner from turning on. In this case, it’s time to replace the thermostat. 

If you’re unsure about which thermostat to choose for your residence, don’t hesitate to seek advice from an Expert who can help you make the best decision.

2. Check The Air Filter

Clogged air filter, a common issue in faulty ACs

Changing your air filter every 30-60 days is recommended for optimal performance. However, if you have pets, more occupants in your home, or live in an area with high air pollution, it may be necessary to change it more frequently. Neglecting to replace a dirty air filter can impede airflow, potentially causing your air conditioner to freeze and fail to function.

If your air filter appears dirty or you can’t remember the last time it was changed, it clearly indicates it’s time to install a new one. If your air conditioner has frozen, allow it to thaw after replacing the filter before turning it back on.

3. Check The Circuit Breaker

To check if the circuit breaker connected to your air conditioner is tripped, open the electrical panel inside your home. Look for the switch, which should be in the “ON” position. If it has moved to the “OFF” position, that indicates a tripped breaker. Simply flip the breaker back to the “ON” position to resolve this issue.

If your air conditioner continues to trip the breaker even after fixing this issue, it may indicate a more serious problem. In such cases, it is highly recommended that you contact the Experts at Air Comfort Systems. 

We possess the expertise to address the issue promptly and prevent potential damage to your home or air conditioner.

4. Check The Indoor Shutoff Switch

If your AC won’t turn on, it’s possible that the indoor shutoff switch, often mistaken for a light switch, has been unintentionally flipped. Look for this switch near your furnace, closet, crawl space, or attic. Once you locate it, ensure it’s in the “OFF” position. 

If it is, you’ll need to switch it back on. Labelling this switch to prevent accidental shutdowns is always a good idea.

5. Check The Outdoor Shutoff Switch

If you or someone has recently serviced your air conditioner, it’s possible that the external shutoff switch was turned off as a safety measure. Start by locating the external shutoff switch, which should be close to your AC unit.

If the switch is currently in the “OFF” position, switch it on to enable your air conditioner to start functioning again.

6. Identify The AC’s Reset Button

If your air conditioner fails to turn on, it might be necessary to reset it. While not all AC units have a reset button, you should determine if your unit does. If a reset button is present, press it before switching your AC back on. 

If you can’t locate the reset button, manually reset your air conditioner by turning off your thermostat for five to 10 minutes before switching it back on.

7. Inspect The AC For Ice Buildup

Inspect the air conditioner thoroughly for any signs of icy buildup on or within the unit. If you notice ice on your machine, allowing it to melt completely before starting the unit is crucial. Failure to do so may result in damage to your AC. 

While there can be various reasons for the presence of ice on your air conditioner, it is always advisable to seek a consultation from Air Comfort Systems to prevent further harm.

8. Ensure The Condensate Drain Isn’t Clogged

The condensate drain may be backed up if you don’t see ice on your air conditioner. As a safety measure, your AC won’t turn on when clogged. To fix this issue, use a wet/dry vac to suction out the blockage from the drain line. 

Once you’ve done that, test if the blockage is resolved by pouring a small amount of clear water and observing if it flows smoothly. If the clog is severe, it’s recommended to seek professional assistance.

AC Still Won’t Turn On? Call Air Comfort Systems!


Don’t endure the discomfort of a sweltering home without air conditioning. Contact our knowledgeable HVAC Experts in Austin for professional assistance in diagnosing why your AC won’t turn on. 

Our highly skilled technicians are well-equipped to troubleshoot and identify the root cause of the issue, providing effective repairs or expertly installing a replacement unit if necessary. 

Rest assured, with Air Comfort Systems, your satisfaction is guaranteed!

Take the first step towards a cool and comfortable home by contacting or visiting us to schedule your air conditioning appointment in Austin today! 

Our team is ready to provide you with top-notch service and ensure your AC is up and running quickly.