Why is My AC Unit Blowing Warm Air Inside of My Lexington, SC Home?

Summer is in full swing here in Lexington, SC, and that means your air conditioning system is working harder than ever. With the combination of high heat, humidity, and constant usage, HVAC issues are more common this time of year—and we’ve been busy helping homeowners across the area stay cool and comfortable. Here are the top 5 HVAC repairs we’re seeing this summer, and what you can do to avoid them. 1. Refrigerant Leaks Low refrigerant levels are one of the most common summer problems we see. Over time, small leaks can develop in the system, leading to reduced cooling, longer run times, and increased energy bills. Signs to watch for: Warm air blowing from vents AC running nonstop Hissing or bubbling sounds near the outdoor unit Our fix: We locate and seal the leak, recharge your system with the correct amount of refrigerant, and make sure everything is running at peak efficiency. 2. Clogged Condensate Drain Lines Lexington’s humidity causes your AC to remove a lot of moisture from the air. That water drains through a condensate line, which can become clogged with algae or debris, leading to water damage or system shutdowns. Symptoms include: Water pooling around your indoor unit Musty odors Sudden AC shutoff We can clear the blockage and get your system draining properly to prevent future issues. 3. Dirty Air Filters It may seem simple, but dirty or clogged filters are behind many of the service calls we handle in the summer. Poor airflow puts extra strain on your system, reduces cooling performance, and can even cause your evaporator coil to freeze. What to look for: Weak airflow Uneven cooling in rooms Higher energy bills Tip: Check and replace your air filter every 1–2 months—especially during the summer. 4. Electrical Component Failures Summer heat can stress key components like capacitors and contactors, causing them to overheat or fail. When this happens, your AC may not start or may shut off unexpectedly. Common signs: Clicking or buzzing noises AC won’t turn on Short cycling (frequent starting and stopping) We carry replacement parts on our trucks and can usually fix these issues quickly. 5. Frozen Evaporator Coils Yes, it sounds odd in the middle of summer—but frozen coils are more common than you think. Poor airflow or low refrigerant can cause the coil to freeze, stopping your system from cooling your home. Watch for: Ice buildup on the indoor unit Reduced airflow AC runs but doesn’t cool the home We’ll diagnose the cause, safely defrost your unit, and make any necessary repairs. Don’t Sweat It—Call Your Local HVAC Experts in Lexington At Brian’s Heating & Cooling, we’re proud to serve homeowners across Lexington and the Midlands with honest, fast, and dependable HVAC service. Whether you’re dealing with a small issue or a full system breakdown, we’re here to help. 📞 Call us today or schedule your service online to stay cool and comfortable all summer long!

When summer hits Lexington, SC, the heat and humidity can be relentless—and the last thing you want is your air conditioner blowing warm air. At Brian’s Heating & Cooling, we hear this complaint all too often during peak summer months. If your AC isn’t keeping your home cool and comfortable, there could be several common issues at play. Let’s break down the most frequent reasons your AC might be blowing warm air—and what you can do about it. 1. Your Thermostat Is Set Incorrectly It may sound obvious, but we always start here. If your thermostat is accidentally set to “heat” instead of “cool”, your AC will blow warm air. Double-check the settings, and make sure the fan is set to “auto” instead of “on” (which can circulate warm air when the system isn’t actively cooling). 2. Refrigerant Levels Are Low or Leaking Refrigerant is the substance your AC uses to absorb heat and cool your home. If your system is low on refrigerant—or if there’s a leak—your AC won’t be able to cool properly. This is not a DIY fix. Call a licensed HVAC technician in Lexington to inspect and recharge the system if needed. Pro Tip: Refrigerant issues often come with other symptoms like hissing noises, ice buildup on the coils, or reduced airflow. 3. Dirty or Clogged Air Filters A dirty air filter restricts airflow, causing your system to work harder and potentially overheat. When this happens, the system may blow warm or room-temperature air. We recommend replacing your air filter every 1–3 months, especially during the summer when your AC runs constantly in Lexington’s high humidity. 4. Electrical Issues or Blown Fuses Sometimes, the indoor unit is working, but the outdoor condenser isn’t. This can happen due to a tripped breaker or a blown fuse. If the outdoor unit isn’t running, the system can't complete the cooling cycle—leaving you with warm air. A quick inspection of your circuit breaker panel may reveal the problem. If a fuse has blown or a breaker continues to trip, it's time to call an HVAC professional. 5. Frozen Evaporator Coils Ironically, frozen coils can cause warm air. When the evaporator coil freezes, it can’t absorb heat properly, which interrupts the cooling process. This can be caused by low refrigerant, dirty filters, or blocked airflow. If you notice ice forming on your AC unit, shut it off and contact our Lexington HVAC team right away. 6. A Faulty Compressor The compressor is the heart of your AC system, pumping refrigerant between the indoor and outdoor units. If the compressor fails, your system can’t cool at all. This is a serious issue that usually requires professional repair or replacement. 7. Poor Maintenance or Lack of Seasonal Tune-Ups Regular HVAC maintenance is essential in Lexington, SC, where AC systems are under constant stress during hot summers. Neglected systems are more prone to breakdowns, warm airflow, and costly repairs. At Brian’s Heating & Cooling, we offer affordable maintenance plans to keep your system running at peak performance year-round. Check out our maintenance service page to learn more! What Should You Do if Your AC Is Blowing Warm Air? Check the thermostat settings. Inspect your air filter. Ensure the outdoor unit is running. Call a trusted local HVAC company in Lexington, SC. Trust Brian’s Heating & Cooling for Fast, Reliable AC Repairs in Lexington, SC When your AC is blowing warm air in the middle of a South Carolina summer, don’t wait. At Brian’s Heating & Cooling, we’ve been serving the Lexington community for years with fast, honest, and affordable HVAC service. Whether it’s a refrigerant leak, a dirty coil, or a faulty thermostat, our certified technicians will diagnose and fix the problem quickly—so you can get back to enjoying a cool, comfortable home. 📞 Call us today at 803-796-1788