Top Charleston HVAC Services for Your Heating and Cooling Needs

There’s nothing more frustrating than walking into your home on a hot Charleston day, expecting a blast of cool air, and getting nothing but a warm breeze. When your air conditioner isn’t cooling properly, it can quickly make your living space uncomfortable and expensive. At Prestige Heating & Air, we get calls every summer from homeowners wondering why their AC isn’t keeping up. While every situation is unique, there are a few common reasons that tend to pop up again and again.

In this blog, we’ll share the top five reasons your air conditioning system might not be cooling as it should and what you can do about it.

1. Dirty or Clogged Air Filters

This is by far the most common issue, and thankfully, one of the easiest to fix. Your AC system relies on proper airflow to cool your home efficiently. When the air filter gets clogged with dust, pollen, and debris, it chokes the airflow, making your system work harder and deliver less cool air. Check the filter if your home feels warm even with the AC running. Most homes need a new filter every 1–3 months, especially in Charleston’s humid climate, where systems run longer.

Pro Tip: Replace your air filter and set a reminder to check it monthly during peak seasons.

2. Low Refrigerant Levels

Your air conditioner uses refrigerant to absorb heat from inside your home and release it outside. If the system is low on refrigerant, it can’t do its job effectively, which means warm air from your vents and longer run times. Low refrigerant typically means there’s a leak somewhere in the system. You may also notice ice forming on the refrigerant lines or the evaporator coil and strange hissing noises.

What to Do: Call a professional. Handling refrigerant requires special certifications and tools. A licensed HVAC tech can find the leak, repair it, and recharge your system safely.

3. Thermostat Issues

Sometimes the problem isn’t with the AC unit—it’s the thermostat. If your thermostat isn’t calibrated correctly or is located in a spot that doesn’t reflect your home’s actual temperature, it could be shutting the system off too early or not turning it on when it should. Smart thermostats can also have software or connectivity problems that interfere with normal operation.

How to Check: Make sure your thermostat is set to “cool,” not just “on” or “fan.” Try lowering the set temperature by a few degrees and see if that triggers cooling. If not, it may be time for a thermostat repair or upgrade.

4. Blocked or Leaky Ductwork

Your air conditioner could be running perfectly, but the cool air won’t reach your rooms if your ductwork is leaking or blocked. This is a hidden issue for many homes, especially older ones with aging duct systems. Leaks in the ductwork can cause cooled air to escape into attics, crawl spaces, or walls before it ever reaches your vents. Dirty ducts or collapsed sections can also restrict airflow, leaving rooms unevenly cooled.

Solution: Schedule a duct inspection. Sealing or repairing ducts can improve your AC performance dramatically and help you save on energy bills.

5. Aging or Undersized AC Unit

If your HVAC system is over 10–15 years old, it may be losing efficiency or not adequately sized for your home. An undersized system will constantly run without thoroughly cooling your space, especially during Charleston’s hot and humid summers. Similarly, an oversized unit can short-cycle (turning on and off too quickly), which wastes energy and doesn’t effectively dehumidify the air.

What to Watch For: Frequent cycling, rising energy bills, and poor comfort levels are all signs your system might be at the end of its life or improperly matched to your home.

Next Steps: A professional load calculation and consultation can help you determine whether it’s time for an upgrade and which size system best fits your home.

Trust Prestige Heating and Air for All Your Charleston HVAC Needs

When your air conditioner isn’t cooling properly, it’s not just a comfort issue—it’s also a sign that something deeper may be wrong. Whether it’s a quick fix like replacing the filter or a more significant issue like low refrigerant or leaky ducts, catching the problem early can save you from costly breakdowns later.

At Prestige Heating & Air, our local Charleston, South Carolina, HVAC company offers fast diagnostics, honest recommendations, and dependable HVAC repairs to help you stay cool all summer. If your AC isn’t working, reach out—our HVAC services are here to help.