Now that we’re knee-deep in summer, it seems like the only reprieve from the heat and humidity is inside our cool, climate-controlled homes. Your air conditioner may be the only thing that stands between you and sweating in your living room, but did you know that air conditioners are not designed to run constantly?

    In fact, if your air conditioner never shuts off, it may be a sign of one of these five problems.


    1. Your air filter is clogged.

    When it comes to your air conditioner’s efficiency, circulation is critical. Without it, all the dust and debris in a dirty air filter keep your air conditioner from receiving the airflow it needs to cool effectively and then turn off.

    Change your filter according to the manufacturer’s directions, usually once every 30 to 90 days, for maximum airflow. 

    Bonus: A clean air filter will keep dust and allergens from infiltrating your house. A clogged filter prevents proper air circulation through the HVAC system. The evaporator coil can only absorb enough heat from the air with adequate airflow. Consequently, the air conditioner cannot reach the set temperature and disengage.

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    To keep your system running efficiently, inspect and replace dirty filters once a month during peak cooling season. Use the MERV rating system to select optimal filtration that balances dust removal with airflow. 


    2. You are running low on refrigerant.

    Your air conditioner requires refrigerant to cool the evaporator coils. As your unit ages, leaks are likely to develop, causing refrigerant levels to drop. In some cases, these leaks are slow enough that recharging your refrigerant level is all it takes to improve your air conditioner’s cooling capacity.

    The refrigerant circulates through the condenser and evaporator coils to absorb and release heat. With low refrigerant, the cycle cannot efficiently lower the temperature. The evaporator coil will be slightly warm rather than cold, preventing your thermostat from reaching the set temperature and shutting off the air conditioner.

    While refrigerant leaks are common as AC systems age, they can also indicate serious problems like a faulty evaporator, condenser, or compressor. Have an HVAC technician evaluate refrigerant levels and identify any underlying issues, such as leaking evaporator coils.

    3. Your home lacks insulation.

    Your home constantly gains heat from outside sources such as the sun, nearby machinery, and car engines. Proper insulation creates resistance to heat flow and helps your home stay temperate. With inadequate insulation, it takes more work for your air conditioner to overcome heat infiltration and achieve the desired indoor temperature.

    If your air conditioner is constantly running, inspect insulation levels around your home, especially in the attic. Then, replace old or missing insulation for maximum energy efficiency. Ensure insulation achieves the recommended R-value for your climate zone. You can even tint windows or install heat-reflective film to block solar heat gain.

    4. You have air leaks in your ductwork.

    Leaky ducts force your air conditioner to work overtime to cool your home. Sealing ducts is a cost-effective way to boost AC efficiency. Inspect accessible ducts for detachments, gaps, kinks, or punctures. Also, check connections at vents and registers and use mastic sealant or metal tape to patch leaks.

    Consider hiring an HVAC technician to perform a duct pressure test for inaccessible ducts. They will seal all vents except one, then use specialized equipment to check for leaks as air flows into the ducts. This process allows them to isolate and repair hidden leaks you cannot access alone.

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    5. Dirty Coils, Condenser or Ducts

    No one expects their car to run without an oil change, but we sometimes feel like our air conditioners should run without a regular tune-up.

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    Regular HVAC maintenance is the best way to ensure your unit runs as efficiently as possible. Dirty coils, a dirty condenser, or clogged ducts can contribute to an air conditioner that constantly runs without completely cooling your home.

    Fortunately, the solution is as simple as having a specialist perform an HVAC tune-up before summer. They can clean the areas of your air conditioner most susceptible to dirt and recommend any necessary repairs to help you avoid mid-summer meltdowns. Addressing any of these issues can extend the life of your air conditioner and keep you cool all summer.


    So, Is an Air Conditioner Running Constantly Always a Problem?

    An air conditioner that never shuts off is usually a sign of an underlying issue that needs attention. Identifying and quickly addressing problems will restore cooling efficiency and prevent system failure.

    However, it is normal for your air conditioner to run most of the day during stretches of intense heat. I recommend setting your thermostat at a moderate temperature instead of a maximally cold setting to avoid overworking the unit. Ensure your home’s insulation, windows, and ducts are optimized to reduce unnecessary heat gain. Also, replace filters regularly and have an HVAC technician perform seasonal maintenance to keep your air conditioner operating at peak performance when needed.

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    FAQs About Air Conditioners Running Constantly

    Why does my air conditioner freeze up?

    A frozen evaporator coil indicates low refrigerant levels or reduced airflow. Lack of refrigerant or airflow prevents the coil from absorbing enough heat, leading to ice formation. Have an HVAC technician check the refrigerant charge and system airflow.


    How can I tell if my AC issues are serious?

    Warning signs of serious AC problems include strange smells, smoke, dirty air discharge, frequent fuse-blowing, or loud noises from the unit. If you notice these issues, shut off your air conditioner immediately and contact an HVAC professional.


    Should I repair or replace my air conditioner?

    Consider replacement if your AC unit is over ten years old and experiences frequent breakdowns. Newer AC units are significantly more energy efficient, saving you money on energy bills each month. Reference our guide on the cost of a new unit.


    What maintenance can I do myself?

    DIY maintenance includes monthly inspecting and changing air filters, cleaning debris from outdoor AC units, and trimming plants and branches blocking outdoor units. HVAC technicians should handle any tasks involving refrigerant, electrical work, or ducts.


    How often should my AC be serviced?

    HVAC experts recommend professional tune-ups before peak cooling season, generally in the spring. Technicians inspect refrigerant levels, electrical components, condenser and evaporator coils, drain lines, and overall performance. I recommend a fall tune-up to prep the system for winter.


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    Elisabeth Beauchamp

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    Elisabeth Beauchamp is a content producer for Today’s Homeowner’s Lawn and Windows categories. She graduated from the University of North Carolina at Chapel Hill with degrees in Journalism and Linguistics. When Elisabeth isn’t writing about flowers, foliage, and fertilizer, she’s researching landscaping trends and current events in the agricultural space. Elisabeth aims to educate and equip readers with the tools they need to create a home they love.

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    Amy DeYoung

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    Amy DeYoung has a passion for educating and motivating homeowners to improve their lives through home improvement projects and preventative measures. She is a content writer and editor specializing in pest control, moving, window, and lawn/gardening content for Today’s Homeowner. Amy utilizes her own experience within the pest control and real estate industry to educate readers. She studied business, communications, and writing at Arizona State University.

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