Why Your AC Can’t Keep Up on Hot Days in Morristown, AZ

Living in Morristown, AZ, during the summer feels like living on the surface of the sun. For five straight months, daytime highs in Morristown rarely drop below 100°F. When temperatures stay that high for that long, the odds of your AC going out on a triple-digit day increase significantly.

If your air conditioner can’t keep up on hot days already, it won’t take much more before it gives out completely, and in Morristown, that simply isn’t an option.

In this blog, you’ll learn how to stay safe and comfortable through the worst summer heat and why Mountainside Air is the best choice for AC services in Morristown, AZ.

Signs That Your AC Won’t Make It Through the Summer

If you notice any of these AC issues around your home, fix them now before you’re left without air this summer:

• Your indoor temperature consistently stays 4-7 degrees above your thermostat setting.
• Your supply vents blow air that feels only slightly cooler than room temperature.
• Moisture collects on windows, and humidity makes your home feel muggy.
• Your system runs three times longer than it did last summer.
• Your utility bill shows a dramatic spike compared to last year’s summer bills.

Common Reasons Your AC Can’t Keep Up on Hot Days in Morristown, AZ

These are the most common reasons our technicians find when AC systems struggle to keep up in Morristown, AZ.

Undersized AC Units Can’t Handle the Heat

Undersized systems run constantly because they don’t have the capacity to remove heat fast enough to match your home’s cooling demand. Rooms near the thermostat feel cooler, but distant rooms stay warm. Air moves through the ducts, but the airflow from your vents feels weak. Your compressor stays on during the hottest parts of the day, which wears out components and drives up energy bills.

Replacing your unit with one properly sized for your home restores consistent cooling and prevents this nonstop cycle.

Poor Insulation Lets Heat In

When your attic lacks insulation, heat from the roof moves directly into your living space and warms the air you’re trying to cool. Leaks around windows, plumbing, and outlets let warm air creep in while conditioned air escapes through cracks in the structure. Your air conditioner keeps working to cool air that won’t stay inside, which extends run times and lowers efficiency.

Adding attic insulation and sealing air leaks helps your system hold cool air in and keeps your house from reheating too quickly.

Low Refrigerant Levels Reduce Cooling

Your system needs a sealed refrigerant loop to remove heat from your home and release it outside. When that loop leaks, even a small drop in pressure lowers how much heat the system can move with each cycle. Your vents blow air that feels too warm, and ice builds on the refrigerant lines as pressure drops further and airflow slows down. The compressor keeps running, but cools less air each time.

Dirty Air Filters Choke Airflow

If your AC can’t keep up on hot days in Morristown, AZ, check your air filter. Dust-packed filters block airflow at your return and slow circulation through the entire system. As resistance builds, your blower works harder to push air forward, but less of it reaches the coil, limiting how much heat your system absorbs and how much humidity it removes. When airflow drops too low, the coil freezes over and stops air from moving. The ice traps heat and forces your compressor to run under strain.

Replacing your filter every month during summer keeps air moving freely and helps your system avoid these failures.

Bad Thermostat Settings Waste Energy

Thermostats placed on hot walls or near appliances read inaccurate temperatures and destroy your HVAC system’s efficiency. Setting your thermostat too low increases cycle times and adds strain without making your home feel cooler.

Frequent manual adjustments prevent your system from reaching a stable temperature and force it to work harder throughout the day. Standard thermostats also ignore humidity, which affects comfort just as much as temperature.

Set yours to 78°F and leave it. For better control, install a smart thermostat with sensors in the rooms you actually use.