In brief
An AC running all day during a heat wave isn't automatically broken. Most residential systems are designed to cool about 18–22°F below outdoor temps. Learn the real warning signs, quick fixes you can do yourself, and when it's time to call a pro.
July put every system in the Triangle to the test. Here's a look at the 703 jobs our crews completed last month, three calls worth retelling, and what those calls say about what to check at your own house.
Read article
Toilet installation in the Raleigh-Durham area typically runs between $400 and $1,200. Here's exactly what drives that range and how to get a licensed plumber out to your home for $49 or less.
Read article
A look at the real plumbing jobs Nick Pleasants and Chris Dick handled across Apex, Cary, Raleigh, and the rest of the Triangle this June, with the cause and the fix for each.
Read article
Licensed & Insured
Fully licensed and insured for your protection
24/7 Emergency
Available when you need us most
16+ Years
Decades of trusted service
When a heat wave rolls through Apex, Raleigh, or Cary and temperatures climb past 100°F, the calls start coming in fast. Homeowners are worried their air conditioner is broken because it never seems to shut off. In most cases, the system is doing exactly what it should — just working a lot harder than usual.
Understanding why your AC struggles in extreme heat, and knowing the difference between normal strain and a real problem, can save you an unnecessary service call — or help you catch a serious issue before it becomes a full breakdown.
Most residential air conditioning systems are engineered to maintain indoor temperatures roughly 18 to 22 degrees below the temperature of the air entering the system. On a mild 85°F day, that math is easy — your system cycles on and off comfortably and keeps your home in the low-to-mid 60s without much effort.
But when outdoor temps push into the upper 90s or past 100°F, the physics get harder. On a 102°F afternoon, your system may run almost continuously and still only hold the mid-to-upper 70s indoors. That's not a malfunction. That's the ceiling of what the equipment was designed to do.
Factors that affect how well your home holds temperature during extreme heat include:
As temperatures drop in the evening, your home will typically begin to catch up. If it does, that's a strong sign your system is healthy — just stretched thin by the conditions.
A system running nonstop during a heat wave is normal. But certain symptoms during extreme heat indicate a real problem that won't resolve on its own.
Call for AC Repair if you notice any of these:
When to call a pro: If you're seeing warm air, ice on the unit, or temperatures climbing despite hours of runtime, don't wait it out. Heat-related stress can push an already-struggling system into a full compressor failure, which is far more expensive to address than the underlying cause.
Before calling anyone, there are several things you can do yourself that genuinely make a difference during a heat wave.
A clogged air filter is one of the most common reasons an AC system underperforms in summer. Restricted airflow forces the system to work harder, reduces cooling capacity, and can eventually cause the evaporator coil to freeze. Check your filter — if it's gray and dense with dust, replace it immediately.
Dirty outdoor coils are one of the biggest efficiency killers during extreme heat. Pollen, grass clippings, and debris accumulate on the condenser coil and prevent the system from releasing heat properly. This puts extra strain on the compressor and can cause the system to trip on high-pressure lockout. Gently rinse the outdoor unit with a garden hose if it looks caked with debris, and make sure there's at least two feet of clearance around it.
Pro tip: Setting your thermostat to 76–78°F during a heat wave instead of 70°F dramatically reduces the load on your system and can be the difference between keeping up and falling behind.
Systems that receive regular HVAC Maintenance consistently outperform neglected ones during extreme heat events. A properly maintained system has clean coils, correct refrigerant charge, calibrated controls, and a blower operating at full capacity — all of which matter most when conditions are at their worst.
An AC Tune-up before summer hits gives your system the best possible chance of handling a heat wave without incident. Technicians check refrigerant levels, clean the coils, inspect electrical connections, and verify that the system is operating within manufacturer specs. Small issues found during a tune-up — a slightly low refrigerant charge, a capacitor showing early signs of failure — are inexpensive to fix before they become emergency calls on a 103°F afternoon.
Prevention tip: Schedule your annual maintenance in the spring, before the first heat wave of the season. Once temperatures spike, availability tightens and wait times increase across the Triangle.
North Carolina summers are particularly demanding on HVAC equipment because of the combination of high temperatures and high humidity. Unlike drier climates where heat alone is the challenge, the Triangle's humid conditions mean your system is simultaneously removing moisture from the air and trying to lower the temperature — two jobs at once.
Homes in areas with significant tree cover (common in neighborhoods around Chapel Hill, Carrboro, and parts of Raleigh) may stay cooler naturally but can also have outdoor units that accumulate debris faster. Newer construction in fast-growing areas like Fuquay-Varina, Morrisville, and Holly Springs often has better insulation and tighter envelopes, which helps — but systems in those homes are also often sized for the home's design load, with little margin for extreme outlier days.
If your system is more than 10 to 12 years old and struggling to keep up during heat waves, it may be worth having a technician evaluate whether AC Replacement makes more sense than continued repairs. Modern systems are significantly more efficient and better equipped to handle extreme heat events.
Yes, in most cases. Residential systems are designed to maintain indoor temperatures roughly 18–22°F below outdoor conditions. On a 100°F day, your system may run nearly continuously and still only hold the upper 70s indoors. As long as air is coming out cool and temperatures aren't climbing, the system is likely working as intended.
Ice on your indoor or outdoor unit is a sign of a problem, not a sign the system is working too hard. It typically indicates restricted airflow (often a clogged filter) or low refrigerant. Turn the system off and call for service — running a frozen unit can damage the compressor.
Setting the thermostat between 76–78°F during extreme heat reduces system strain and helps it keep up. Trying to maintain 68–70°F when it's 100°F outside may push the system beyond its capacity and cause it to run without ever reaching the setpoint.
Low refrigerant typically shows up as warm air from the vents, ice on the equipment, or a system that runs constantly without cooling effectively. A licensed technician needs to check refrigerant levels — this isn't something homeowners can measure or add themselves. Refrigerant Services require EPA-certified handling.
If your system is more than 10–12 years old, has needed multiple repairs in recent seasons, or can't maintain comfortable temperatures even in moderate heat, it may be time to evaluate replacement. A technician can assess whether the cost of repairs is approaching the value of a new system.
