Summers in Boone, NC might be cooler than in other parts of the state, but that doesn’t mean your HVAC system isn’t working hard. Between humidity, temperature swings, and mountain weather, your air conditioning system has its own unique challenges in the High Country. At Edmisten Heating & Cooling, we’ve spent years helping Boone homeowners stay comfortable all summer long. Here are the top 5 HVAC problems we see every summer—and what you can do to help prevent them. 1. Frozen Evaporator Coils Yes, even in the summer your system can freeze up. Frozen evaporator coils are often caused by restricted airflow (usually from a dirty air filter) or low refrigerant levels. When airflow drops, moisture condenses and freezes on the coil—causing your system to stop cooling effectively. What to watch for: Weak airflow from vents Ice visible on indoor unit or lines AC running but not cooling Pro tip: Change your air filter every 1–2 months and schedule regular maintenance to avoid this issue. 2. Low Refrigerant Levels Low refrigerant means your system can’t properly cool the air. This usually indicates a leak, which needs to be located and repaired. Boone’s elevation and shifting temps can increase wear on HVAC lines and joints, making leaks more likely over time. Signs include: Warm air blowing from vents Longer cooling cycles Hissing or bubbling sounds near the unit Solution: Call our team to locate the leak, recharge your system, and get things running smoothly again. 3. Clogged Condensate Drain Line Your AC removes moisture from the air, which drains through a line to the outside. But in humid climates—yes, even in the mountains—algae and debris can clog this line, causing water to back up into your home or shut off your system entirely. Common symptoms: Water around your indoor unit Musty odors Sudden AC shutdowns Regular inspections and cleaning during seasonal tune-ups can prevent blockages and water damage. 4. Thermostat Issues In Boone’s variable climate, we see thermostats struggle with incorrect readings or sudden system changes. Sometimes, it’s just an aging thermostat—or it could be a poor location (too close to windows or vents) throwing off your temperature control. What to look for: Inconsistent indoor temps System short cycling or not turning on Unresponsive or blank thermostat Consider upgrading to a programmable or smart thermostat to improve accuracy and efficiency. 5. Outdoor Unit Obstructions Boone’s lush summers are beautiful—but leaves, grass, and even small critters can obstruct your outdoor condenser unit. When airflow is restricted, your AC system has to work harder, which can lead to overheating and eventual failure. What you can do: Keep at least 2 feet of clearance around the unit Gently hose off debris Check for signs of nesting or animal activity Beat the Heat with Expert HVAC Care in Boone, NC At Edmisten Heating & Cooling, we know the unique HVAC challenges that come with living in the mountains. Our local team is here to keep your system running efficiently so you can stay cool and worry-free all summer long. Need a repair, tune-up, or just have questions about your system? 📞 Call us today or schedule your service online