Outside AC compressor not turning on? Frustrating, isn’t it? But don’t worry, we’ve got you covered. In this article, we’ll explore the common reasons for this issue, how to troubleshoot it, and when to call a professional HVAC technician. Plus, we’ll share some preventative measures to help you avoid such problems in the future.

If your outside AC compressor isn’t turning on, the likely culprits could be issues with your thermostat, electrical problems, an overheating compressor, motor failure, or issues with the compressor start relay. However, it’s essential to diagnose the problem accurately before taking any corrective measures. Let’s talk in detail…
Understanding the Function of an AC Compressor – Outside AC Compressor Not Turning On
Role of the Compressor in an Air Conditioning System
Think of the compressor as the heart of your air conditioning system, pumping refrigerant through the entire unit. Without it working properly, your AC can’t effectively cool your home. So, it’s crucial to understand how it functions to tackle any issues head-on.
How a Compressor Works – Outside AC Compressor Not Turning On
Did you know the compressor is responsible for transforming low-pressure gas into high-pressure gas? It does this by compressing the refrigerant, which then flows through the condenser coils and releases heat outdoors. It’s this process that keeps your home cool and comfortable.
Common Reasons Why an Outside AC Compressor Isn’t Turning On – Outside AC Compressor Not Turning On
Thermostat Issues
Sometimes, the culprit is as simple as a thermostat issue. Let’s look at two common thermostat problems that could prevent your compressor from turning on.
Incorrect Thermostat Settings
Have you checked your thermostat settings lately? Ensure it’s set to “cool” and the desired temperature is lower than the current room temperature. If not, your compressor won’t receive the signal to start.
Faulty Thermostat
Thermostats can fail over time or due to power surges. If you suspect a faulty thermostat, try replacing the batteries or resetting it. Still no luck? It’s time to call a professional.
Electrical Problems – Outside AC Compressor Not Turning On
Electrical issues are another common reason for a compressor that won’t turn on. Here are three electrical problems that could be to blame:
Tripped Circuit Breaker
A power surge or an overloaded circuit can trip the breaker, cutting power to your AC unit. Check your breaker panel and reset any tripped breakers.
Blown Fuse
If your AC has a fuse box, a blown fuse could be the issue. Replace the fuse and see if your compressor comes back to life.
Damaged Wires
Wear and tear or rodent damage can cause wiring issues in your AC unit. If you see damaged wires, it’s best to call a professional to fix them.
Overheating
An overheating compressor can shut down to protect itself. Here are two common causes of overheating:
Dirty Condenser Coils
Your condenser coils, located in the outside unit, can get dirty over time, making it harder for your AC to release heat. This can cause the compressor to overheat and shut down. A good clean can work wonders, trust us!
Lack of Refrigerant
If your AC is low on refrigerant, it can’t effectively cool your home, and the compressor can overheat. You’ll need a professional to check this out and refill the refrigerant if needed.
Motor Failure – Outside AC Compressor Not Turning On
Just like your car, your AC has a motor that can fail over time. Here are a couple of things that can go wrong:
Burnt Out Compressor Motor
If you’re smelling a strong electrical odor from your AC, you might have a burnt-out compressor motor. This is a job for a professional HVAC technician.
Capacitor Issues
The capacitor gives your compressor motor the boost it needs to start up. If it’s faulty, your compressor won’t turn on. Again, call a professional to replace a bad capacitor.
Issues with the Compressor Start Relay
The compressor start relay, like the capacitor, helps your compressor start-up. If it’s faulty, your compressor won’t turn on. You’ll need a professional to test and replace it if necessary.
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How to Troubleshoot an AC Compressor that Won’t Turn On – Outside AC Compressor Not Turning On
Checking the Thermostat
Start with the easy stuff. Check the thermostat settings and replace the batteries if needed. If that doesn’t work, you might need to replace the thermostat.
Inspecting for Electrical Issues – Outside AC Compressor Not Turning On
Look at your breaker panel and AC fuse box for any tripped breakers or blown fuses. Also, inspect your AC for any visible wiring damage. But remember, safety first! Don’t try to fix electrical issues on your own.
Checking for Overheating
If your AC unit is hot to the touch, it could be overheating. Clean your condenser coils and call a professional to check the refrigerant levels.
Inspecting the Motor – Outside AC Compressor Not Turning On
If you smell a strong electrical odor from your AC, you could have a burnt-out motor. This requires a professional’s help.
Examining the Compressor Start Relay
If you’ve checked everything else and your compressor still won’t turn on, it might be the compressor start relay. You’ll need a professional to test and replace it if necessary.
When to Call a Professional HVAC Technician – Outside AC Compressor Not Turning On
Persistent Compressor Issues
If you’ve tried troubleshooting and your compressor still won’t turn on, it’s time to call a professional. They have the tools and knowledge to accurately diagnose and fix your AC.
Electrical Problems That Require Professional Attention – Outside AC Compressor Not Turning On
Remember, electricity is dangerous. If you suspect electrical problems, don’t try to fix them on your own. Call a professional HVAC technician.
Motor Replacement
If your compressor motor is burnt out, you’ll need a professional to replace it. Don’t try to do this yourself, as it can be dangerous and void your warranty.
Preventative Measures to Avoid AC Compressor Issues – Outside AC Compressor Not Turning On
Regular AC Maintenance –
Regular maintenance is key to keeping your AC running smoothly. This includes cleaning your condenser coils, replacing filters, and getting a professional check-up at least once a year. It’s a small price to pay for a comfy, cool home, don’t you think?
Ensuring Correct Thermostat Settings – Outside AC Compressor Not Turning On
Keep an eye on your thermostat settings. Ensure it’s set to “cool” and the desired temperature is lower than the room temperature. A simple tweak here can save you a whole lot of hassle.
Keeping Condenser Coils Clean
Your condenser coils can easily get dirty, causing your compressor to overheat. Make a habit of cleaning them regularly to keep your AC running efficiently.