A/C on Overload? What to Do When Your System Can’t Keep Up With the Heat

can your a/c take the heat?

If you live in East Tennessee, you already know that summer in the Tri-Cities isn’t just warm weather. It’s hot, humid, and relentless at times! When outdoor temperatures soar into the upper 80s and 90s with humidity levels above 70%, even the best air conditioners can start to struggle. If your home feels warmer than it should—even with the AC running nonstop—you’re not alone.

At Phil’s Heating and Air, we’ve helped hundreds of homeowners in Gray, Johnson City, Kingsport,   Bristol, and the Tri-Cities Region navigate this exact issue. Here's why your system might be lagging behind and what you can do to fix it.

Why Your AC Can’t Keep Up in Extreme Heat

Your air conditioner is designed to cool your home by approximately 15–20 degrees lower than the outside temperature. So when it’s 95° - 100°F+ outside, your A/C may only be able to keep your home around 75–80°F—and that’s under ideal conditions. If you’re seeing higher indoor temps like this, there could be other issues at play. Never fear though. We can help!

Common Causes of Underperforming A/C

1. Dirty Air Filters

Clogged filters restrict airflow, forcing your system to work harder. This not only reduces cooling efficiency but can also increase energy use by up to 15%, according to the U.S. Department of Energy.

Tip: Check and replace your filter every 30–60 days during peak use months (May - August). Phil's Heating and Air will change your air filters and keep your HVAC system running optimally without you ever having to lift a finger with our Preventative Maintenance Services.

2. Leaky Ductwork

Leaking ducts can lose 20–30% of cooled air before it ever reaches your living spaces. In older or unsealed homes, this can significantly impact comfort levels.

Phil’s Pro Fix: We offer duct inspections and sealing services to ensure every bit of cool air makes it to your vents. Contact us to learn more.

3. Low Refrigerant Levels

If your system is low on refrigerant due to a leak or improper charge, it won’t be able to absorb heat effectively. Signs include warm air blowing from vents, ice buildup on coils, and A/C freeze-ups.

Pro Tip: Refrigerant isn’t used up like fuel—if it's low, there’s likely a leak that needs professional repair. Call us at (423) 741-5459 to ensure you don't have a refrigerant leak, and explore our HVAC Repair Services.

4. Oversized or Undersized Units

Bigger isn’t always better. An oversized AC will short-cycle, never properly dehumidifying your home, while an undersized unit can run endlessly without reaching your desired temperatures. Choosing the right sized system is not always easy. Don't trust the plumbers or a handyman with this one! Contact us to find the optimal unit for your home or business.

Phil’s Solution: We offer load calculations to ensure your system matches the size of your home and its cooling demands.

5. Neglected Maintenance

Without regular maintenance, parts wear down, airflow is restricted, and energy efficiency plummets. A well-maintained system can last 40% longer and perform up to 25% more efficiently, according to ENERGY STAR. Even better, the TVA and U.S. Government are now offering UNPRECEDENTED HVAC REBATES for small repairs up to full system installations. Rebates will only last for a limited time, so now is the time maintain, repair, or install new HVAC Systems!

Phil’s Heating and Air provides seasonal tune-ups, priority service, and exclusive discounts to keep your AC in peak shape year-round all under our standard Preventative HVAC Maintenance Services. We are also offering a $2,800 REBATE for new energy-efficient Amana HVAC System Installations. 

Quick Steps You Can Take Right Now

✅ Set Your Thermostat Wisely: Keep it at 76 - 78°F when home. Raising the temperature a few degrees can significantly ease the load on your system.

✅ Use Fans Strategically: Ceiling and box fans help circulate cool air and allow you to feel cooler without lowering the thermostat. Running fans during the hottest portions of the day can help move cool air throughout your home while keeping your family cool in the process.

✅ Keep Blinds Closed: Up to 30% of unwanted heat comes through your windows. Keep curtains or shades drawn during peak sunlight hours to avoid the "greenhouse effect".

✅ Avoid Heat-Producing Appliances: Use the oven and dryer during the early morning or late evening hours when outdoor temperatures are lower. This will keep excessive heat at bay when the sun is at it's strongest.

When to Call Phil’s Heating and Air...

If your AC is running but just can’t keep up—or worse, it’s blowing warm air, making strange noises, or turning on and off frequently—it’s time to give us a call. Our expert technicians are familiar with the unique cooling needs of mountain properties in East Tennessee, and we’re here to help with:

• Complete AC diagnostics and repair
• Refrigerant checks and recharge
• Duct inspection and sealing
• Smart thermostat installation
• System upgrades and replacements
• Preventive seasonal maintenance

Explore our Services to learn more

Stay Cool, Tri-Cities

Don’t wait until your AC gives out completely. A struggling system wastes energy, shortens its own lifespan, and makes your home feel miserable. Contact Phil’s Heating and Air today—we’ll help get your system back on track so you can enjoy real relief this summer. Everyone deserves for their home to be a haven from from the elements. Let's explore the options so you can gain back control of YOUR indoor climate!

📍 Serving Gray,  Johnson City,  Kingsport,  Bristol, and surrounding areas. Check out our Service Area to see if we serve your town!

📞 Call or text us today, or schedule online at our Contact Page.