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April 26, 2024

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    If your air conditioner is older, you could be losing money each month by paying more to run an outdated system that’s lacking in efficiency. Plus, as your HVAC system ages, it’s more likely to break down and leave you with expensive repairs. That makes hanging onto your system more expensive than replacing it.

    In this guide, we’re going to call on our years of experience to explain when you should replace your AC and how to know when a full replacement will save you more than avoiding paying for a new system.

    We recommend reaching out to some local HVAC installation companies to get quotes for the replacement to do a cost-versus-value analysis to decide if AC replacement is your best option.

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    • If you have an older AC unit, it might be more cost-effective to replace it instead of paying to repair it.
    • There are often obvious signs your AC needs to be replaced, like higher energy bills and strange noises from the unit.
    • A certified HVAC technician can help you decide whether it’s time to replace your air conditioner.

    7 Signs It’s Time To Replace Your Air Conditioner

    It’s not always obvious when your AC system needs to be replaced, so in most cases, you’ll have to rely on a professional system diagnosis to determine the issue, severity, and solution. However, there are seven important things to look out for which can indicate that your system is nearing the end of its useful lifespan. These include the following:

    We’ll discuss these signs in greater depth in the following sections.

    You See Noticeable Increase in Your Energy Bill

    Your air conditioner uses electricity to cool your home, and the efficiency rating — usually expressed as a SEER rating (seasonal energy efficiency ratio) or SEER2 rating — dictates how much electricity is consumed to cool your living area. As your system ages, it will naturally decline in terms of efficiency.

    Over time, that translates to higher and higher energy costs to provide the same amount of cooling. If you notice that your cooling costs are higher than they were in previous years, it might mean that replacing your AC is in order.

    Your AC Is Blowing Warm Air

    One of the most common — and most frustrating — issues you can have with an AC involves your indoor AC unit blowing warm or hot air rather than cool, refreshing air. There are a few things that can cause this problem.

    First, your refrigerant levels could be low. Refrigerant — usually Freon (R-22 refrigerant) or Puron (R410a), depending on the age of your cool air system — is a substance that transfers heat from the air in your home to the outside through evaporation and condensation. If your system has a refrigerant leak, it could be a sign that the equipment is old and should be replaced.

    Second, you could have an issue with your evaporator coils, your heat pump, or your condenser fan motor. These pieces are essential for the refrigerant to be able to do its job. They can be costly to replace and may warrant a total AC replacement if your current system is old enough or lacks efficiency.

    Related: Does Your AC Start Cold Then Get Warm?

    Your AC System Is Making Strange Noises

    Outdoor condensers and indoor AC units make some noise during operation, but if you start to hear grinding or whirring noises coming from either piece of the system, you might want to consider replacing your AC.

    Worn belts, loose parts, or malfunctioning blower motors, condenser fan motors, or compressors are common reasons why your AC is making unusual sounds. In any of these cases, your first order of business should be to call in an AC repair technician to get your system checked. If the solution is an expensive one, a full replacement might make more sense, depending on the age and condition of your current AC.

    You’re Experiencing Minimal Airflow

    In some cases, problems with the blower motor in your indoor HVAC unit can lead to a lack of air coming out of your vents at all. If you notice reduced airflow, you can first try replacing your air filters, which will also improve your indoor air quality. If that doesn’t work, we suggest contacting a reliable HVAC contractor to come to take a look.

    Once again, the issue could be small, like a broken belt on your blower motor. If that’s the case, then a quick repair should fix your problem. If your tech finds that your blower motor needs to be replaced entirely, you could be looking at up to $2,000 for the repair. If your system as a whole is also old and losing efficiency, then it might be more affordable in the long run to replace your entire AC system instead.

    Your Unit Is Leaking

    In some cases, you might find that your indoor AC unit leaks water onto the floor or into the drain pan. This could be caused by a clogged condensate line, which requires a quick and easy fix.

    Unfortunately, the problem could also be a result of a refrigerant leak and the resulting lower pressure inside your system. If the refrigerant is the problem, it could be a sign of an aging system, and a replacement might be a smarter option than a repair. You’ll need a professional to help assess the leak and determine the best course of action for you.

    You Know Your System Is Old

    The average air conditioner system lasts for around 15 years. Some of the best AC models can keep functioning for up to around 20 years, and some budget options may only last around ten years, especially if you don’t carry out annual HVAC maintenance.

    If you know your AC is reaching the end of its expected life, you should consider replacing it preemptively. This could save you some money since you won’t need to pay for a rush service, and it also means you won’t have to deal with the sweltering summer temperatures with an AC that goes down unexpectedly.

    The Frequency of Maintenance Is Increasing

    Finally, if you notice that your air conditioner needs more frequent repairs than it has in the past, it’s a good indication that your equipment could be reaching the end of its life expectancy. New air conditioners can often run for a decade or more with just the bare minimum service, like an annual AC tune-up to keep efficiency high and operation normal.

    If you find that you’re calling an HVAC technician in once a year or more to resolve problems with your system, then it’s probably time to replace it.

    Read also: How Often Do You Need To Add Freon To A Central Air Conditioning Unit?

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    You’ll spend more up front buying a new unit, but over time, the new system will likely pay for itself thanks to higher energy savings and reduced HVAC repair costs.

    When Should You Replace Your Air Conditioner by Unit Type?

    The information above can apply to any type of air conditioner, but the lifespan and average AC replacement costs can vary based on the kind of system you have in your home. The table below includes some general information about a few of the more common AC varieties, including the typical system lifespan.

    TypeLifespanAverage CostUnique Benefit
    Central Air Conditioner15-20 years$5,500 (if you already have ductwork and an air handler installed)Quiet operation and whole-home cooling
    Ductless Mini SplitAround 20 years$5,000No ductwork needed and long lifespan
    Window AC Unit8-10 years$300Very affordable and removable
    Geothermal AC System25-30 years (around 50 years for outdoor equipment$24,000Consumes less energy and has a long lifespan
    Portable AC5-10 years$400Very affordable and suitable for many window styles

    Repairing Vs. Replacing Your Air Conditioner

    With the replacement costs of most of the permanently installed systems above reaching over $5,000, most homeowners will wonder whether they should replace or repair their ACs.

    The answer depends on a few factors. First, we recommend calling an HVAC technician to come out and assess your problem. They can determine if a repair is possible or financially viable or if a total replacement will end up saving you more in the long run.

    Generally speaking, you can usually get away with an HVAC repair rather than a replacement if you have one of the following problems:

    • A leak from your indoor unit that is fixed by clearing your condensate line
    • Reduced airflow from your system that is fixed by replacing your air filters
    • Your AC is blowing warm air, but the problem is found to be dirty evaporator coils

    In some cases, you can carry out regular maintenance yourself. You may just need to replace a part, and the price of AC capacitors and other parts is significantly lower than full AC replacement. As the video below explains, keeping your outdoor condenser unit clear of any overgrowth and removing dust, dirt, and other debris from your condensate line are great ways to keep your AC up and running for longer. Routine maintenance like this can extend the life of your AC system and reduce your long-term repair costs:

    What’s Our Recommendation on When To Replace an AC Unit?

    In our experience, being proactive and replacing your AC at the end of its average lifespan — usually around 15 years — is a great way to avoid outages and maintain maximum efficiency. We also suggest replacing your AC if you notice your energy bills creeping up during the warmer months or if you notice you’re calling for HVAC maintenance more regularly.

    Even if you think you know what the issue is with your system, we recommend contacting a professional in your area to get an assessment and an estimate for repair or replacement. AC systems are complicated, and what might look like a simple issue could be a much more complicated one that demands a full replacement. The opposite is also true, so a local HVAC technician is your best bet for getting the most cost-effective solution to your AC issues.

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    FAQs About Replacing an AC Unit

    What should I do with my old AC unit?

    Unfortunately, you can’t just leave air conditioners out for waste collection services, as the Environmental Protection Agency (EPA) mandates that the refrigerant be reclaimed first. This helps cut down on ozone layer destruction and potentially harmful emissions.

    If you’re replacing a larger system, like a central air conditioner, a ductless mini split, or a geothermal AC system, your AC installer should either remove the old system for you or explain where the equipment can be disposed of properly. If you’re looking to get rid of an old wall or window AC or a portable AC, we recommend you contact your local jurisdiction’s waste collection department about potential curbside pickup or AC recycling options.

    How long does it take to install a new AC unit?

    If you’re installing a new window or portable AC, you can DIY the installation in just a few minutes with no tools in most cases. If you’re getting a new ductless mini-split or central air conditioning (CAC) system installed, your installation company will likely take between four and eight hours to complete the work. More complicated cooling systems like geothermal air conditioners can take several days to install.

    Will a new AC unit increase the value of my home?

    In most cases, yes. Savvy homebuyers who understand the potential savings they may enjoy from a new, efficient AC system might be willing to pay more for your home. Plus, a new AC system means they’ll have peace of mind that the equipment is unlikely to give them issues for years after they purchase the home, again reinforcing the value added by replacing your air conditioner.

    Can I still use my old thermostat with a new AC unit?

    Editorial Contributors
    avatar for Dan Simms

    Dan Simms


    Dan Simms worked in real estate management for five years before using his experience to help property owners maintain their own homes. He got his master’s degree in English Literature and Creative Writing, and he now enjoys sharing his knowledge about homeownership and DIY projects with others on Today’s Homeowner. When he’s not writing, he’s usually outdoors with his wife and his dog, enjoying mountain biking, skiing, and hiking.

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    photo of Andrew Dunn

    Andrew Dunn

    Senior Editor

    Andrew Dunn is a veteran journalist with more than 15 years of experience reporting and editing for local and national publications, including The Charlotte Observer and Business North Carolina magazine. His work has been recognized numerous times by the N.C. Press Association and the Society of American Business Editors and Writers. He is also a former general contractor with experience with cabinetry, finish carpentry and general home improvement and repair. Andrew earned a degree in journalism from the University of North Carolina at Chapel Hill, as well as a certificate in business journalism. He lives in Charlotte, N.C.

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