Why Is My AC Not Working? A Troubleshooting Guide
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If your AC won’t turn on, the cause can range from a minor issue to something more serious. The most common culprits are tripped circuit breakers and a malfunctioning thermostat.
We know how frustrating it is when you need cool air and all you’re getting is stress. Our troubleshooting guide will explore both the common and less obvious reasons your AC may not be working, along with practical fixes. If these solutions don’t resolve the issue, it’s time to call a professional.
Need a second opinion on why your AC isn’t working? Call us to speak with a technician!
Top 7 Reasons Your AC Isn’t Turning On: What to Do
Troubleshooting your air conditioning system involves a process of elimination. We’ll start with the easiest DIY fixes, then move into the situations that need a professional eye.
1. Switch Turned Off
Sometimes the simplest problems have the simplest solutions. You may have accidentally turned your unit off while doing some spring cleaning. If you recently had a maintenance appointment, the technicians might have flipped the safety switch and forgotten to turn it back off.
What Should You Do?
Learning how to troubleshoot AC problems means reflecting on any other household activity that could’ve caused the issue. Double-check the switch, then review anything else that might have been unplugged or switched off recently.
2. Tripped Circuit Breaker
Did you recently have any home repairs or maintenance done? Similar to above, sometimes technicians need to turn off the circuit breaker before they can safely work, but neglect to turn it back on again.
Your circuit breaker may have also been overwhelmed by a surge in electricity, such as plugging in a faulty appliance or as a side-effect from a storm.
What Should You Do?
You can either reset your circuit breaker by turning the AC switch off, then on again after a few seconds. If your AC still doesn’t turn on, but you still suspect the circuit breaker is the issue, you need to call a professional to inspect it.
3. Incorrect Thermostat Settings
Your thermostat not only gives you a quick read of your indoor and outdoor temperature, it also tells your AC when to turn on or off. Sometimes your settings aren’t accurate, leading your AC to turn off when it’s still warm (or not turn on at all).
What Should You Do?
You can check your thermostat by switching it to a higher or lower setting to see which readings trigger a shutdown. If you still suspect some strange readings, you can try buying a second thermostat, placing it in the same room, and comparing both readings.
This trick will give you a good idea on whether or not you should call a professional for thermostat calibration. If your unit still doesn’t turn on and stay on despite changing the settings, a technician can test your thermostat or install a new one.
4. Dirty Air Filter
Dirty air filters are one of the most common AC unit problems because it’s easy to overlook this maintenance, especially if you rarely use your system. If your unit doesn’t have proper circulation because of clogged filters, its inner coils can freeze up.
An AC that can’t get consistent airflow sometimes shuts down as a safety measure.
What Should You Do?
Replacing the air filter might fix the problem. How often should you change your air filters? We recommend changing your air filters once every few months (or sooner if you live in an area with a lot of pollen or air pollution).
However, if your system still doesn’t turn on, it may be frozen over and need professional help to unthaw.
5. Debris
If you’re asking why your AC isn’t working in the summer when it was fine during the winter, it may have accumulated some debris. Outdoor AC units need to be cleaned off regularly to function.
Dirt, dust, and leaves can slow down its airflow or clog its coils, both of which can result in a shutdown.
What Should You Do?
Inspect your AC for any visible corrosion. You can wipe down fan blades with a dry cloth and brush off leaves by hand. You can also spray down condenser coils with a hose and water.
If you don’t feel comfortable cleaning your unit, you can call a technician for yearly maintenance. We recommend calling in winter or spring before the weather gets too hot.
6. Low Refrigerant
If you’ve had your air conditioning unit for years and use it on a regular basis, you might have low refrigerant. This chemical is not only crucial for changing the air’s temperature, it’s essential for the system to run smoothly in the first place.
An air conditioning unit with low refrigerant is more likely to short-cycle and even overheat, which could increase the risk of a fire.
What Should You Do?
Call a professional. Refrigerant is a chemical that needs to be handled carefully and technicians have the expertise to refill your system again.
7. Failed Capacitator
What is the most common part to fail on an AC unit? It’s usually the capacitor. If your AC unit won’t turn on and you hear strange humming, you may have a failed capacitor on your hands.
Other signs of this issue include strangely high energy bills, a burning smell, or warm air.
What Should You Do?
Learning how to troubleshoot your AC means knowing when to skip the DIY route and call for help. A failed capacitor is both expensive and potentially hazardous. This issue always needs professional assistance to be fixed safely.
How to Reset Your AC: Step-by-Step
If you’ve recently had a power outage and your AC has stopped working, you can reset it. The reset button is helpful for overriding the system’s built-in protective measure against electrical surges.
Turn off your AC’s power with the circuit breaker.
Press the reset button (you may have to hold it down for a few seconds).
Restore power by turning on your circuit breaker’s AC section again.
Set your thermostat to the cool setting.
Stand next to your AC for a few minutes to make sure it’s blowing cool air again.
A reset won’t work with an AC unit that’s shutting down due to a failed capacitor, frozen coils, electrical issues, or low refrigerant.
How to Diagnose What’s Wrong
Learning how to troubleshoot your AC unit should involve a proactive attitude. Always keep an eye out for the following issues in the future so you can get help as soon as possible:
Weak airflow, such as a room taking too long to cool
Constant cycling on and off
Strange odors like burning or sulfur
Unusually high energy bills with no explanation
6 Signs You Need Repair or Replacement
Not sure if you should repair your AC or get a new energy-efficient installation? You should try a repair job if:
Your AC system is only a few years old and usually works well
You maintain your unit on a yearly basis
You suspect a minor problem, such as frozen coils or a thermostat issue
However, you should consider a replacement if:
Your AC system is eight years old or older
You’ve been calling for multiple repair jobs over the past few years
You can’t stay cool and comfortable for long
When You Should Call a Professional
If you still have electrical issues or repeated malfunctions, a professional can finally get to the root of the issue and provide a solution. YES! Air Conditioning, Heating, and Plumbing has been providing dependable, friendly repair services throughout Utah and Nevada since 1971.
Not only can our expert technicians diagnose and fix your AC’s problem, we can help you with issues like preventative maintenance or keeping repairs within your warranty.
Let us help you with troubleshooting your AC system. Give us a call to send a technician over!