Quick Answer
If your AC is running but not cooling, check your air filter first—a clogged filter is the #1 cause and costs just $5-15 to fix. Other common causes include frozen coils, low refrigerant, or a failed capacitor. Most repairs cost $200-$800. In Charlotte's summer heat, don't wait—AC problems worsen quickly.
It's 95°F in Charlotte, and your AC is running—but it's not cooling. The thermostat says 85°F inside, and you're starting to sweat. Before you panic and call for emergency service, know this: many AC cooling problems have simple fixes you can do yourself in minutes.
In this guide, we'll walk through the 10 most common reasons your AC isn't cooling, starting with the easiest DIY fixes. We'll tell you exactly what to check, what each repair typically costs, and when you actually need to call a professional. After 16+ years fixing Charlotte ACs, we've seen it all—and most problems are more manageable than you'd think.
Quick Fixes You Can Do Right Now (DIY)
Before calling anyone, try these fixes. They take 5-10 minutes and solve roughly half of all "AC not cooling" calls we receive. Seriously—check these first.
1. Check Your Air Filter (Most Common Cause)
A dirty air filter is the #1 reason ACs stop cooling effectively. When the filter clogs, it restricts airflow across the evaporator coil. The coil gets too cold, ice forms, and your AC blows warm air instead of cold.
How to Check Your Filter
Cost to fix: $5-$30 for a new filter. Time: 2 minutes. This simple fix could save you a $150+ service call.
2. Verify Your Thermostat Settings
We see this more often than you'd think. Here's what to check:
Thermostat Checklist
- Mode is set to COOL (not Heat or Fan Only)
- Temperature is set BELOW current room temperature
- Fan is set to AUTO (not ON)—"ON" runs the fan constantly even when not cooling
- Batteries are fresh (if applicable)
- Thermostat isn't in direct sunlight or near a heat source
The "Fan ON" Mistake
3. Check Your Circuit Breakers
Your AC has two parts: the indoor air handler and the outdoor condenser unit. Each has its own circuit breaker. If the outdoor breaker trips, your indoor fan keeps running—but there's no cooling happening outside.
How to Reset Your AC Breaker
- 1
Find Your Electrical Panel
Usually in the garage, basement, or utility closet.
- 2
Locate the AC Breakers
Look for two breakers labeled "AC," "Air Handler," or "Condenser." They're typically 20-60 amp double breakers.
- 3
Check for Tripped Breakers
A tripped breaker sits in the middle position—not fully ON or OFF.
- 4
Reset Properly
Flip the breaker fully OFF, wait 30 seconds, then flip it ON. If it trips again immediately, stop—you have an electrical problem that needs professional diagnosis.
💡 Never repeatedly reset a tripping breaker. This can cause electrical fires.
4. Clear Your Outdoor Unit
Your outdoor condenser releases heat from your home. If it's blocked by debris, covered in dirt, or surrounded by overgrown landscaping, it can't release heat effectively. We see this constantly in Charlotte yards.
Outdoor Unit Checklist
- Clear 2 feet of space around all sides of the unit
- Remove leaves, grass clippings, and debris from the unit
- Gently rinse condenser fins with a garden hose (not a pressure washer)
- Ensure the unit is level—settling can cause problems
- Check that the disconnect switch near the unit is ON
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Problems That Need Professional Repair
If the DIY fixes above didn't solve your problem, you likely have one of these issues. These require specialized tools, refrigerant handling certification, or electrical expertise.
5. Low Refrigerant (Refrigerant Leak)
Unlike your car's AC, your home system doesn't "use up" refrigerant. If it's low, you have a leak. Signs of low refrigerant include:
- AC blowing cool but not cold air
- Ice forming on refrigerant lines or the indoor coil
- Hissing or bubbling sounds near the indoor unit
- Higher-than-normal humidity in your home
- Electric bills increasing despite normal use
Why You Can't Fix This Yourself
Typical repair cost: $200-$800 depending on leak location and refrigerant type. Systems using R-410A (most units made after 2010) are less expensive to recharge than older R-22 systems.
6. Frozen Evaporator Coil
If your AC has been struggling to cool, ice may have formed on the indoor evaporator coil. This usually happens because of restricted airflow (dirty filter, blocked vents) or low refrigerant. The ice acts as insulation, preventing the coil from absorbing heat.
How to Thaw a Frozen Coil
- 1
Turn OFF the AC
Switch the thermostat to OFF or HEAT (not cool).
- 2
Keep the Fan Running
Set the fan to ON. This circulates warm air over the frozen coil to speed thawing.
- 3
Wait for Complete Thaw
This takes 2-24 hours depending on ice thickness. Don't try to chip away ice—you can damage the coil.
- 4
Check and Replace Your Filter
A dirty filter is the most common cause of frozen coils.
- 5
Test the System
Once thawed, run the AC. If it freezes again within 24 hours, you likely have a refrigerant leak—call a professional.
7. Failed Capacitor
Capacitors are small electrical components that store energy and give your compressor and fan motors the boost they need to start. In Charlotte's hot, humid climate, capacitors fail frequently. This is the most common repair we perform.
Signs of a bad capacitor:
- AC tries to start but shuts off immediately
- Humming sound from outdoor unit but it won't start
- Outdoor fan spins slowly or not at all
- AC works intermittently
- Clicking sounds followed by no startup
Kodiak Technician
Typical repair cost: $200-$300 including parts and labor. This is a 20-30 minute repair that gets your AC running immediately.
8. Failed Contactor
The contactor is an electrical switch that controls power to the compressor and outdoor fan. When it fails (often from burnt or pitted contacts), the outdoor unit won't run even though it's getting power.
Typical repair cost: $250-$400. Like capacitors, this is a quick repair that restores cooling immediately.
9. Compressor Failure
The compressor is the heart of your AC system—it pumps refrigerant and makes cooling possible. When it fails, your AC stops cooling entirely. Signs include:
- Outdoor unit runs but doesn't cool
- Loud grinding, squealing, or clanking sounds
- Outdoor unit repeatedly trips the breaker
- AC runs constantly but home never reaches set temperature
Compressor Repairs Are Expensive
10. Ductwork Problems
Leaky or disconnected ducts cause your AC to run but not cool effectively. Cool air escapes into your attic or crawlspace instead of reaching your rooms. We see this frequently in Charlotte homes with flex duct in unconditioned attics—the connections can come loose over time, especially with temperature fluctuations.
Signs of duct problems:
- Some rooms much warmer than others
- Weak airflow from certain vents
- Dusty air coming from vents
- Energy bills increasing without explanation
- Rooms that never reach the set temperature
Typical repair cost: $200-$800 depending on accessibility and extent of damage. Duct sealing typically pays for itself in lower energy bills within 1-2 years.
AC Repair Costs in Charlotte (2026)
Here's what you can expect to pay for common AC repairs in the Charlotte market. These prices include both parts and labor from a licensed HVAC contractor.
Common AC Repair Costs
| Repair | Typical Cost | Time |
|---|---|---|
| Air Filter Replacement | $5-$30 | DIY |
| Capacitor Replacement | $200-$300 | 30 min |
| Contactor Replacement | $250-$400 | 30 min |
| Refrigerant Recharge + Leak Repair | $200-$800 | 1-3 hours |
| Thermostat Replacement | $200-$800 | 30 min |
| Blower Motor Replacement | $400-$900 | 1-2 hours |
| Evaporator Coil Cleaning | $200-$400 | 1-2 hours |
| Condenser Fan Motor | $300-$600 | 1-2 hours |
| Compressor Replacement | $1,500-$3,500 | 3-5 hours |
Prices include parts and labor. Diagnostic fee ($89 at Kodiak) typically waived with repair.
Real Customer Review★★★★★"Our AC quit on the hottest day of summer. Kodiak came out same day, fixed a bad capacitor for $200, and it's been perfect since. Way less than I feared."
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$89 diagnostic fee waived with repairs. Same-day service available.
How to Prevent AC Cooling Problems
Most AC breakdowns are preventable. Here's what we recommend to keep your system running reliably through Charlotte's brutal summers:
AC Maintenance Checklist
- 1
Change Your Filter Every 30-60 Days
During peak AC season (May-September), check your filter monthly. Charlotte's pollen and humidity clog filters fast.
💡 Set a phone reminder for the 1st of each month.
- 2
Keep Your Outdoor Unit Clear
Maintain 2 feet of clearance around the condenser. Trim plants back, clear debris after storms.
- 3
Don't Close Too Many Vents
Closing vents to "unused" rooms creates pressure imbalances that strain your system and reduce efficiency.
- 4
Schedule Professional Maintenance
Have your system inspected and tuned up twice yearly—spring for AC, fall for heating. This catches small problems before they become big ones.
- 5
Listen for Changes
New sounds, smells, or changes in performance often signal developing problems. Address them early.
Save 15% on Repairs
Should You Repair or Replace Your AC?
This is the question everyone dreads. Here's our honest guidance:
Repair vs. Replace Decision Guide
| Feature | Repair | Replace |
|---|---|---|
| System Age | Under 10 years | Over 12-15 years |
| Repair Cost | Under $500 | Over 50% of new system cost |
| Refrigerant Type | R-410A | R-22 (phased out) |
| Repair History | First major repair | Multiple repairs recently |
| Energy Bills | Stable | Increasing significantly |
| Comfort | System keeps up | Can't cool adequately |
Kodiak HVAC Advice
When to Call for Emergency AC Service
Most AC problems can wait until normal business hours. However, call for immediate service if:
- You smell burning or see smoke from any AC component
- Indoor temperatures exceed 90°F with vulnerable family members (elderly, infants, those with medical conditions)
- Water is leaking near electrical components
- You hear sparking sounds or see electrical arcing
- The outdoor unit is making grinding metal-on-metal sounds
If You Smell Burning
Frequently Asked Questions
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Written by
Kodiak HVAC Team
HVAC professional at Kodiak Heating & Cooling.