AC Won’t Turn On? Here’s What Might Be Going Wrong
- Tyler Thomas
- Jun 10
- 6 min read
Nothing is more frustrating than your air conditioner refusing to start on a hot summer day. Whether you are in the middle of a heat wave or just trying to cool down your home, discovering that your AC won't turn on can cause stress, discomfort, and urgency.
Before you assume the worst, know this: many issues are easy to fix if you know what to look for. At Abel Heating and Cooling, we have been solving HVAC problems since 1944 for homeowners, businesses, and congregations across the Twin Cities metro. Our certified technicians are trained to diagnose all issues quickly and honestly, offering expert advice and fair, transparent pricing.
This blog walks you through the top 14 reasons why your AC may not be turning on and provides actionable steps to get things running again.
Basic Troubleshooting: Start Here If Your AC Won’t Turn On
1. Thermostat Settings Are Incorrect
Sometimes the issue is as simple as a thermostat that is not set to “cool.” Make sure it is powered on, set to “cool,” and the temperature is at least five degrees lower than the current room temperature. If the screen is blank, try replacing the batteries.
A malfunctioning thermostat may also fail to communicate with the system entirely. If you suspect this is the case, call a technician for diagnosis.
2. Tripped Circuit Breaker
This is one of the most common culprits behind an AC that will not start. If the breaker trips during a power surge or due to high voltage usage, the system will shut off as a safety precaution.
Check your breaker panel and reset any tripped switches. An underlying electrical issue may require professional repair if the AC keeps tripping the breaker.
3. Blown Fuse
If your AC is getting power but still not running, a blown fuse might be the cause. Fuses protect against electrical overload and can degrade over time.
Blown fuses must be replaced carefully; repeated failures can indicate a serious problem. Always contact a licensed HVAC technician to inspect and replace fuses safely.
Intermediate Issues That Stop Your AC From Turning On
4. Dirty or Clogged Air Filter
Clogged filters restrict airflow, leading to overheating or freezing, which triggers system shutdown. You may also notice weak airflow or a spike in energy bills.
Replace your air filter every 30 to 60 days. If you have pets, allergies, or smoke indoors, more frequent changes may be needed.
5. Frozen Evaporator Coil
When airflow is blocked or refrigerant is low, the evaporator coil can freeze. Ice buildup prevents your AC from working and can damage the system.
Turn off the system and allow the coil to thaw completely. This may take up to 24 hours. Avoid using the unit until a technician confirms it is safe.
6. Clogged Drain Line or Overflowing Drain Pan
AC systems remove humidity from the air. If the condensate drain line is clogged or the drain pan is full, a safety switch may activate to prevent water damage.
You can try clearing the line using a wet/dry vac. For deeper clogs or recurring issues, contact our team for a professional indoor air quality and drainage assessment.
Stay Cool and Stress-Free This Summer with Abel’s AC Checklist
Before the summer heat hits full force, make sure your cooling system is ready with Abel Heating and Cooling’s Air Conditioning Checklist for Summer. From replacing filters and clearing outdoor units to inspecting drain lines and adjusting your thermostat, these simple steps can help you boost efficiency, lower energy bills, and avoid unexpected breakdowns.
Need a professional tune-up? Our experienced technicians are here to help you prep your system for peak performance.
Schedule your maintenance appointment today and enjoy a worry-free summer.
External or Component-Specific Problems
7. Outdoor Disconnect Switch Turned Off
Your AC system has a shutoff switch in a metal box near the outdoor unit. This is often flipped during maintenance and forgotten.
Make sure the pullout head is inserted correctly and the switch is in the “on” position.
8. Electrical Wiring Damage
Due to weather and wear, wiring can corrode, fray, or come loose over time. Exposed or damaged wires can stop power flow and pose serious risks.
If you suspect faulty wiring, do not attempt to fix it yourself. Call a professional for safe inspection and repair.
9. Capacitor Failure
The capacitor helps start and run your AC motor. It is susceptible to heat and electrical surges.
If you hear clicking or buzzing when the unit tries to start or the fan does not spin, the capacitor may be bad. Replacing capacitors is dangerous and should always be done by a qualified HVAC expert.
10. Compressor or Motor Issues
The compressor is the heart of your AC system. If it fails, you may hear humming, see increased energy usage, or experience frequent shutdowns.
Motor or compressor failure is often a sign that your system is aging. Abel Heating and Cooling can provide a second opinion and walk you through repair or replacement options without pressure.
Other Reasons Why Your AC Won’t Turn On
11. Low or Leaking Refrigerant
If refrigerant levels are too low or there is a leak, your AC may not start or may shut down during operation.
Never try to add refrigerant yourself. Our certified technicians can test for leaks, recharge the system, and restore cooling in line with manufacturer specs.
12. Dirty Condenser Coils
The outdoor condenser can accumulate dirt, leaves, and debris. This reduces the system’s ability to release heat and can lead to shutdown.
Clear visible debris and schedule seasonal tune-ups to keep your system clean and efficient.
13. Improper Unit Size
If your unit is too small, it will overwork and overheat. If it is too large, it may short-cycle and fail to operate properly.
Abel’s experts can evaluate your home or business and recommend a correctly sized system to optimize performance and energy use.
14. Aging System
If your AC is over 12 to 15 years old and needs frequent repairs, it may simply be at the end of its lifespan.
We offer fair, honest consultations and affordable financing to help you upgrade without stress or surprises.
Frequently Asked Questions
Why is my AC not turning on?
Common causes include incorrect thermostat settings, a tripped breaker, a blown fuse, dirty air filters, frozen coils, or electrical issues. If basic troubleshooting does not work, it is best to call a licensed HVAC professional.
How do I force restart my AC?
Turn off the thermostat
Turn off power to the outdoor unit at the breaker or shutoff box
Wait 5 to 10 minutes
Turn power back on
Set the thermostat to cooling mode
If this does not resolve the issue, contact a technician. Repeated resets can do more harm than good.
Why is my AC unit not kicking on?
If your AC does not make any noise or attempt to start, it could be due to a thermostat failure, a tripped disconnect switch, capacitor problems, or internal damage. A professional can diagnose the issue safely and quickly.
How do I know if my AC fuse is blown?
If your system has power but still will not run, and you hear clicking but no startup, the fuse may be blown. Use a multimeter to check continuity, or have a technician inspect it. Never replace fuses repeatedly without addressing the root cause.
Why Choose Abel Heating and Cooling?
Abel Heating and Cooling is a family-owned business based in Minnetrista, Minnesota, serving the Twin Cities area for over 75 years. We offer:
Transparent pricing
Certified indoor air quality consultants
Custom HVAC design and energy efficiency consultations
Fair second opinions and satisfaction guaranteed service
We treat our customers like family because many of them are. With expert technicians, a commitment to doing things right the first time, and strong community roots, we are the team you can trust when your AC will not turn on.
Don’t Wait—Schedule AC Repair or Service with Abel Today
If your AC will not turn on and you are tired of guessing what is wrong, we are here to help. The experienced team at Abel Heating and Cooling will diagnose the issue, explain your options, and get your system running smoothly again with no hidden surprises.
Serving the Twin Cities Metro
Call us at 952-243-4367
Let us bring comfort back to your home with service you can trust since 1944.
