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Why Does My AC Keep Running? 6 Common Problems & Solutions

Close-up of an AC fan

Summers can be quite hot in Indiana, averaging highs in the 80s from June until August, but that doesn’t mean your air conditioner should run constantly.

Even on the hottest days, it’s supposed to turn on and off as needed to keep your home at the perfect temperature. This constant operation can damage your AC and even cause premature failure.

If your air conditioner isn’t cycling on and off as it should, this guide will explain some of the most common issues that can cause the system to run constantly and the solutions you need to fix them.

Filter Issues

A dirty or clogged air filter can restrict airflow, causing your air conditioner to run longer to keep your home cool. During the hottest parts of the summer, it’s a good idea to check the air filter at least once a month.

Turn off the air conditioner, then remove and inspect the filter. If it looks dirty, replace it with a new one, or if it’s a reusable filter, clean it and reinstall it.

Most standard 1-inch filters last about three months, while HEPA filters last six to 12 months. Replacing your air filter should be part of your spring AC checklist.

Airflow Problems

Anything that interferes with air movement through the AC unit can cause abnormally long run times. This can include:

  • Blocked or closed vents
  • Leaky air ducts
  • A faulty blower motor

Ensure all air vents are open if they have dampers, and check for any furniture, curtains, or debris blocking the ducts.

If the problem persists, check your air ducts for leaks. You may need ductwork repair. Otherwise, the cause is likely the blower motor, and you’ll need AC repair.

Thermostat Issues

Accidentally setting the thermostat too low can force your air conditioner to keep running, even if your house is icy cold.

Double-check the temperature settings, and make sure the fan is set to “auto” instead of “on” so your system can cool your home effectively. This will also help lower your summer electric bills.

If your thermostat is unresponsive, you may need a repair or replacement.

Dirty or Frozen Evaporator Coils

The evaporator coils in your AC are directly responsible for cooling the air in your home. As hot air is passed over the coils, refrigerant vaporizes, cooling the air. Dirty or frozen coils can’t absorb heat from the air effectively, forcing your system to run all the time.

If the coils are dirty, have them cleaned by an HVAC technician to avoid damage. If they’re frozen, turn your thermostat setting from “cool” to “off,” set the fan to “on,” and allow the coils to thaw naturally before turning the cool air back on.

Low or Leaking Refrigerant

If your AC doesn’t have enough refrigerant, it will have trouble cooling your home and will run more than normal, but it may not blow cool air. Check for signs of a refrigerant leak, such as:

  • Bubbles in your evaporator coils
  • Hissing noises
  • Leaks from your unit

Have any leaks repaired by a qualified HVAC technician, then have the refrigerant topped off so your system can operate as efficiently as possible.

Undersized Unit

An undersized system will take longer than normal to cool your home. Although the system may work well for a few years and cool your home effectively, as it ages, its performance may drop enough to affect your comfort.

If you suspect your air conditioner is undersized, contact a professional HVAC contractor. They can discuss:

Expert AC Services in Indiana

Are you having problems with your air conditioner? Whether it’s running all the time, not at all, or just not cooling your home properly, Northern Comfort Systems can help. We’ve served Indiana homeowners and business owners for over 20 years, offering AC repairs, replacements, and maintenance.

We provide excellent service on every visit, and our commitment to quality has earned us eight Angi Super Service Awards, a 2020 Best of Home Advisor award, and great reviews from our customers.

You can count on our team for upfront pricing with solutions tailored to your needs, and all our services are backed by a 100% satisfaction guarantee.

Get fast help with all your AC problems. Contact Northern Comfort Systems today to request air conditioning repair in Indianapolis, Terre Haute, Anderson, or Muncie.

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