A Florida homeowner’s guide to diagnosing the most common summer nightmare. It’s 95°F outside, your AC has been running for hours, and your thermostat still reads 82°. You’re not imagining it — and you’re not alone. This is one of the most common calls we get here in South Florida, and the good news is there are a handful of known culprits that a trained technician can identify and fix quickly. Here’s what’s likely going wrong — and what you should do right now.

The Most Common Causes

Low Refrigerant A refrigerant leak means your system can’t absorb heat. This is the #1 culprit in Florida. Dirty Air Filter A clogged filter chokes airflow and forces your system to work without result. Frozen Evaporator Coil Restricted airflow or low refrigerant can ice up the coil, blocking all cooling. Failing Capacitor The outdoor unit may be running but the compressor isn’t — a common Florida heat failure. Wrong-Sized Unit Wrong-sized equipment runs constantly but never reaches your set temperature. Dirty Condenser Coils Florida’s outdoor air is full of debris. Clogged coils can’t release heat outside.

What to Check Before You Call

Before picking up the phone, run through this quick checklist. It takes five minutes and could save you a service call — or help us diagnose the problem faster when we arrive. First, check your air filter. If it’s grey and dense with dust, replace it immediately and give the system 30 minutes to recover. Next, look at your outdoor unit — is the fan spinning? If the unit is humming but the fan isn’t moving, your capacitor has likely failed. Finally, check the area around your indoor air handler. If you see ice or frost on the copper lines, shut the system off and call us — running a frozen coil causes compressor damage.

• Check your air filter status
• Inspect outdoor condenser fan spinning
• Monitor indoor lines for ice & frost buildup

Florida Tip: In peak summer, your AC should be able to keep your home about 20°F cooler than the outdoor temperature. If it’s 97°F outside, don’t expect 68°F inside — but 77°F is very achievable with a healthy system.

When to Stop Troubleshooting and Call a Pro

If your filter is clean, the outdoor fan is spinning, and there’s no visible ice — but your home still isn’t cooling — you almost certainly have a refrigerant issue or a compressor problem. Both require a licensed HVAC technician with the right equipment. Attempting to add refrigerant yourself is illegal without an EPA 608 certification, and adding the wrong amount can permanently damage your system.

Don’t wait. In Florida’s humidity, a home that can’t cool below 80°F becomes a health risk in hours, especially for children, elderly residents, and pets. TrueCool AC offers same-day emergency service across South Florida — give us a call and we’ll get your home comfortable again fast.

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