HVAC Service Notes & Diagnostics

By Jonnier Exposito – HVAC Technician, Florida

If there’s one thing I’ve learned after years of working on air conditioning systems in Florida, it’s this: most people don’t really know how their AC works — until it stops working.

In this post, I’ll break down everything a homeowner needs to know about air conditioning, from how it works to how to maintain it, spot problems early, and save money.

🔧 How Does an Air Conditioner Actually Work?

Let’s keep it simple: your AC doesn’t create cold air — it removes heat and humidity from inside your home.

Here’s the basic process:

The evaporator coil inside your air handler pulls heat and moisture out of the air. That heat is carried by refrigerant lines to the outside condenser unit. The condenser releases the heat into the outdoor air while a fan blows over the coil. The cooled air is then recirculated back through your home via ductwork.

When everything works right, your home stays cool and dry — even in 98° Florida heat.

🛑 Common AC Problems I See Every Week

Here are the top 5 issues I deal with as an HVAC technician:

1. Low Refrigerant

If your system is low on refrigerant, it’s either leaking or never charged properly. This causes poor cooling and frozen coils.

2. Dirty Air Filters

This is the simplest and most common problem — a clogged filter restricts airflow and puts stress on the system.

3. Clogged Drain Lines

When the drain line clogs, water backs up into your unit, causing leaks or shutting it off.

4. Bad Capacitor or Contactor

If your unit doesn’t turn on or hums without starting, it could be one of these small but critical components.

5. Faulty Thermostat

A miscalibrated or dying thermostat can throw off the entire system.

If you notice warm air, weak airflow, high energy bills, or strange noises, your AC is trying to tell you something.

🧰 How to Maintain Your AC (And Avoid Expensive Repairs)

Preventive maintenance saves money. Here’s what I recommend every homeowner should do:

✅ Change your filter every 30–60 days ✅ Flush your drain line with vinegar once a month ✅ Keep the outdoor unit free of leaves, grass, and debris ✅ Schedule a professional tune-up twice a year

As a technician, I always look for signs of wear before they become breakdowns. A $79 maintenance call can save you a $1,200 compressor failure.

💡 Tips to Lower Your Cooling Bill Without Sacrificing Comfort

Set your thermostat at 76–78°F when home, 80°F when away. Use ceiling fans to circulate air and reduce cooling load. Close blinds and curtains during peak sun hours. Seal leaky windows and doors to keep the cold air in. Don’t block vents with furniture or rugs.

🏠 When Is It Time to Replace Your AC?

If your system:

Is over 12–15 years old Needs constant repairs Can’t cool your home evenly Runs constantly with high power bills…

It might be time to replace, not repair.

I always recommend getting a quote before your system dies completely — that way, you’re not rushing the decision in the middle of a heatwave.

📞 Final Thoughts from Jonnier Exposito

Whether you need a simple filter change or a full system replacement, don’t wait until it’s too late. I’ve seen small problems turn into major issues simply because people didn’t know what to look for.

If you’re in Florida and need help, advice, or just want to learn more about your system — reach out. I’m here to help you stay cool, stay informed, and stay ahead of costly repairs.

This is Jonnier Exposito, your trusted HVAC technician. I fix air, but I also care.