If you’ve found yourself sweating indoors and wondering, why is my AC compressor not turning on, you’re not alone. This issue is more common than most homeowners realize—especially during the hotter days in Vancouver, WA. At Sub Zero Temp Control, we’ve seen just about every cooling system issue you can imagine, and this one tops the list. The good news? In many cases, the fix is easier than you’d think.
Understanding the Role of the AC Compressor
Before we dive into the causes, it helps to know what your AC compressor actually does. It’s the heart of your cooling system—pumping refrigerant through the coils and helping release heat outside. If the AC compressor is not turning on, your system can’t cool your home, no matter how low you set the thermostat.
Common Reasons Your AC Compressor Is Not Turning On
1. Tripped Circuit Breaker
One of the first things we suggest checking is your electrical panel. A tripped breaker can instantly stop your AC compressor from turning on. This often happens after a power surge or if the system is working too hard.
2. Faulty Capacitor or Contactor?
Capacitors and contactors help deliver electricity to your compressor. But over time, they wear out. When they fail, your AC compressor not turning on is often the result. These parts are affordable to replace, but they do require a trained technician.
3. Thermostat Problems
Believe it or not, the issue might not be your compressor at all. Sometimes a malfunctioning thermostat sends the wrong signal—or no signal at all. This keeps the compressor from ever kicking on. We always check this during diagnostics at Sub Zero Temp Control.
Other Issues That May Be to Blame for Your AC Compressor Not Turning On
4. Low Refrigerant Levels
When refrigerant is too low, your compressor may refuse to operate. This is actually a safety mechanism. If your system’s refrigerant is leaking, it’s important to address it quickly. Otherwise, the damage can spread.
5. Overheating Unit
Dirty coils, blocked vents, or poor ventilation can cause your unit to overheat. In turn, this can lead to your AC compressor not turning on at all. If your system smells hot or you hear a buzzing sound, turn it off and call a professional right away.
6. Burnt-Out Compressor Will Leave Your AC Compressor Not Turning On
Unfortunately, compressors can burn out—especially in older systems or if maintenance has been skipped. When this happens, the repair isn’t always cost-effective. We’ve helped many homeowners around Vancouver decide whether repair or replacement is the better move.
What You Can Check Before Calling
If you’re handy, there are a few safe checks you can do before calling Sub Zero Temp Control:
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Make sure your thermostat is set to cool and your desired temperature is lower than the room temp
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Check for tripped breakers or blown fuses
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Inspect your outdoor unit for debris or ice buildup
Still no luck? It’s probably time to let a professional step in.
How We Diagnose an AC Compressor Not Turning On
When we arrive at your home in Vancouver or one of the surrounding areas, we’ll start with a full system check. We don’t just guess. We test everything—from power supply to refrigerant pressure to system signals. Then we give you a clear explanation of what we find and what your options are. No pushy sales tactics—just honest guidance and reliable repairs.
When Repair Isn’t the Best Option
We’re always happy to repair your system when it makes sense. However, if your AC is over 12–15 years old or the compressor is completely shot, we may recommend replacement. That doesn’t mean an automatic big bill. At Sub Zero Temp Control, we help our Vancouver customers find energy-efficient systems that qualify for rebates and offer long-term savings.
Regular Maintenance Can Help Prevent Compressor Failure
We can’t stress this enough—routine maintenance goes a long way in preventing your AC compressor not turning on unexpectedly. When you schedule seasonal tune-ups, we check all the components that could lead to a breakdown later. It’s a small investment that pays off in comfort and peace of mind.
Call Sub Zero Temp Control for Fast, Honest Service
If you’re dealing with an AC compressor not turning on, don’t wait around for the problem to get worse. Our team at Sub Zero Temp Control is ready to help—whether you’re in Vancouver, WA or one of the surrounding communities like Battle Ground, Camas, or Washougal. We’ll show up on time, explain your options, and get your system working again fast.
Contact us today. We’re here to keep you cool—without the stress.
