Estimated Read Time: 9 minutes
AC running but not cooling can turn a South Florida day into a sauna. Here is the good news. Most causes are fixable with quick checks or a targeted repair. Below, we break down the seven most common reasons, what you can try safely, and when to call Aztil Air Conditioning for fast, 24/7 help. If you want to save on service today, keep an eye out for our free service call offer.
First, run this 2‑minute checklist
Before you dive deeper, confirm the basics:
- Thermostat set to Cool, not Heat or Fan Only. Target 72–78°F.
- Replace or clean the air filter if it is gray, dusty, or older than 60 days.
- Verify the outdoor unit is running and not blocked by plants or debris. Keep 2–3 feet clear.
- Check the breaker. Reset only once if tripped.
- Look for water around the indoor unit. A clogged drain can shut cooling down.
If these pass and your home still will not cool, move through the reasons below.
Reason 1: Dirty or blocked condenser coil
Your outdoor unit dumps heat from your home into the outside air. When the condenser coil is matted with lint, grass clippings, or salt-air grime, heat cannot escape. The system runs and runs but hardly cools.
What you can do safely
- Turn off power at the disconnect.
- Gently hose the coil from the inside out. Avoid high pressure that bends fins.
- Trim shrubs to maintain 2–3 feet of clearance and 5 feet overhead.
Why pros help
- Bent fins, burnt wires, and weak capacitors often hide behind a dirty coil. A licensed tech can clean properly, straighten fins, test electrical parts, and confirm refrigerant pressures match the nameplate.
- South Florida’s coastal air accelerates corrosion. We often recommend a coil cleaning schedule every spring.
Reason 2: Low refrigerant or a leak
Low refrigerant reduces heat transfer. The air may feel cool at the vent but never cool enough, and the system might ice over.
Warning signs
- Longer run times, higher bills, hissing at the air handler, or visible frost on lines.
What you can do
- Do not top off on your own. Handling refrigerant requires EPA Section 608 certification. Overcharging or mixing types can damage the compressor.
How Aztil fixes it
- Leak locate with electronic sniffers and UV dye.
- Repair the connection, coil, or line set when possible.
- Weigh in the exact factory charge for performance and warranty protection.
Reason 3: Frozen evaporator coil
If the indoor coil ices up, airflow and cooling plunge.
Causes
- Clogged filter, closed supply registers, weak blower, or low refrigerant.
Steps to try
- Turn the system off and set the fan to On to thaw the coil.
- Replace the filter. Open at least 80 percent of supply registers.
- If ice returns after two hours of cooling, call for service. Recurring ice points to airflow or refrigerant issues.
Why urgency matters
- Running with ice can slug the compressor with liquid refrigerant and lead to a costly failure.
Reason 4: Weak airflow or duct leaks
Even a perfect AC will not cool if the air cannot reach the rooms.
Common South Florida culprits
- Flexible duct runs sagging in hot attics, separated collars at the plenum, or salt-rusted returns in coastal neighborhoods.
What you can check
- Put your hand at several supplies. Weak flow in far rooms hints at duct leaks.
- Look for kinks or crushed flex duct near the air handler.
How we restore airflow
- Measure static pressure, seal leaks with mastic or Aeroseal, balance dampers, and clean debris with Rotobrush when needed.
- Adjust and balance registers as part of our tune-ups so each room gets its share of cooled air.
Reason 5: Failing capacitor, fan motor, or compressor
Your AC may hum but not move heat if key electrical parts are weak.
Telltales
- Outdoor fan slow or not spinning, frequent breaker trips, or a unit that starts then stops quickly.
Why you should not DIY electrical fixes
- Capacitors hold a charge even when off. Fans and compressors require precise amperage and capacitor sizes. Using the wrong part can void warranties.
Our diagnostic approach
- Electronic amperage testing on all motors and the compressor, connectivity checks for burnt or loose wires, and secure relays and contactors. These steps are included in our professional tune-ups.
Reason 6: Thermostat or sensor problems
A misread temperature can keep your system running without effective cooling.
Quick checks
- Ensure the thermostat is not in direct sun or near a lamp.
- Calibrate the thermostat and replace batteries.
When to call
- If rooms are off by more than 3 degrees or short cycling occurs, we test sensors, staging, and control boards to keep runtime and comfort on target.
Reason 7: Undersized, aging, or improperly installed system
If your AC is too small for your home’s load, it will run constantly without catching up. Aging systems also lose efficiency.
Clues
- The home never reaches setpoint in late afternoon. Doors and windows face west with little shade. Home additions were made without updating the system.
What we do
- Perform professional load calculations to verify the right tonnage and airflow. This prevents short cycling and poor cooling when the sea breeze stalls and humidity spikes.
- If replacement is wise, we provide free, no‑obligation estimates and financing options.
When to call a pro in South Florida
Call if you see ice, smell burning, hear grinding, or the breaker trips more than once. Also call if your line set is sweating heavily indoors, there is standing water near the air handler, or cooling falls off after storms.
Why Aztil is a safe bet
- 24/7 emergency response with no extra fees on nights, weekends, or holidays.
- Over 100 trucks dispatched across West Palm Beach, Boca Raton, Pompano Beach, Fort Lauderdale, and Port St. Lucie for fast arrival.
- Google Guaranteed, fully licensed and certified, and compliant with Florida regulations and EPA rules.
How Aztil pinpoints and fixes the cause
We treat every no-cool call like a system audit, not a guess.
- Interview and inspection
- Confirm symptoms, thermostat settings, filter age, drain history, and any power events after afternoon storms.
- Performance testing
- Air temperature split, refrigerant pressures, superheat and subcool, and amp draw on all motors and the compressor.
- Airflow and duct check
- Static pressure, coil cleanliness, blower wheel inspection, register balancing, and duct leakage evaluation. When appropriate, we seal with Aeroseal and document CFM gains.
- Electrical integrity
- Electrical connectivity checks for burnt or loose wires, tight caps, relays and contactors, and breaker condition.
- Drain and IAQ
- Evaporator drain line cleaning, sludge and debris removal, drain pan vacuuming, and algae tableting to prevent future shutdowns. We also recommend UV lights or advanced filtration if mold was present.
Our maintenance tune-up includes thermostat calibration, lubrication of fan motors, filter replacement, condenser coil cleaning, debris removal, refrigerant level checks, complete compressor diagnosis, disconnect box checks, fuse cartridge checks, and more. These steps catch small issues before they become no-cool emergencies.
Prevention tips for lasting cooling
- Change filters every 30–60 days during summer humidity.
- Keep 2–3 feet of clearance around the outdoor unit and rinse coils each spring.
- Pour a cup of white vinegar in the condensate line monthly to reduce algae.
- Schedule preventive maintenance in spring and fall with our Elite Cool Membership for priority service and member-only discounts.
Hard facts that protect you
- Handling refrigerant legally requires EPA Section 608 certification. Our techs hold the required credentials.
- Aztil has served South Florida for over 40 years and operates a fleet of 100+ trucks for the fastest response in Florida.
Special Offers for Faster, Cooler Comfort
- FREE Service Call with Any Repair ($115 Value | New Customers Only). Expires 2026-06-03.
- Elite Cool Membership: 15% preferred discount on repairs for members. Expires 2026-06-03.
- Loyalty Credits: Earn $50 for every year you stay a member, redeemable toward repairs. Expires 2026-06-03.
Call (561) 257-3070 or schedule at https://www.aztilac.com/ to redeem. Mention the Free Service Call offer when you book.
What Homeowners Are Saying
"The AC maintenance service was excellent... Technician Rick Cochran did an excellent job replacing the AC breaker and ensuring that everything was in correct working condition. I really appreciated his kindness and professional demeanor."
–Google Reviewer, West Palm Beach
"I cannot speak highly enough of our super kind technician, Randy... walked us through photos of the issues and offered to take care of it ASAP as he already had the parts in his truck... Exceptional Service from True Professionals - Highly Recommend!"
–Google Reviewer, Boca Raton
"Been with Aztil for ten years, always satisfied with emergency service... arranged new unit install for today… SAME DAY incredible. We can sleep comfortable tonight."
–Google Reviewer, Fort Lauderdale
"Dana cleaned the coils and blower on our older AC today. He did a great job and explained all the steps to me... Very happy with our service from Aztil."
–Google Reviewer, Pompano Beach
Frequently Asked Questions
Why is my AC running but not cooling after a storm?
Power flickers can trip breakers or lock out compressors. Check the breaker once, then call. We will test pressures and capacitors and reset controls safely.
Can low refrigerant be topped off without finding the leak?
That is risky and may be illegal. EPA rules require certified techs to handle refrigerant and address leaks. We locate and fix the source, then charge by weight.
How long should my AC run to cool the house?
On hot, humid afternoons, 15–20 minute cycles are normal. If it runs nonstop and never reaches setpoint, you likely have airflow, refrigerant, or sizing issues.
Will duct leaks really stop rooms from cooling?
Yes. Leaks can lose 20–30 percent of conditioned air. Sealing and balancing restore comfort and cut bills.
What does the Elite Cool Membership include?
Two tune-ups per year, priority scheduling, no overtime charges, and member-only repair discounts. It prevents surprise breakdowns and keeps cooling efficient.
Bottom Line
If your AC is running but not cooling, start with filters, thermostat, and outdoor airflow. If cooling still lags, it is time for pro diagnostics. Aztil Air Conditioning serves West Palm Beach, Boca Raton, Pompano Beach, Fort Lauderdale, and Port St. Lucie with 24/7 help and no after-hours fees. Call (561) 257-3070 or book at https://www.aztilac.com/. New customers can claim a FREE Service Call with Any Repair.
Ready for Fast AC Relief?
Call Aztil Air Conditioning at (561) 257-3070 or schedule at https://www.aztilac.com/ now. Mention the Free Service Call with Any Repair offer. We dispatch from West Palm Beach to Fort Lauderdale daily and back every job with our 100% satisfaction guarantee.
About Aztil Air Conditioning
For over 40 years, Aztil Air Conditioning has served South Florida with 24/7 emergency service, never any after-hours fees, and a fleet of 100+ trucks for rapid response. Our licensed, certified technicians are Google Guaranteed and follow Florida codes and EPA Section 608 rules. We back every repair with a 100% satisfaction guarantee and offer Elite Cool Memberships for priority care and savings.