Woman adjusts AC temperature settings

HVAC systems are crucial to keeping your home comfortable year-round, but with every scorching season that passes, you never know what parts may break next. Or worse, when it’ll be time to pull the plug and face the dreaded expense of a complete air conditioning replacement.

If your current system is acting out of sorts and you’re not sure what type of service it warrants, there are signs to help indicate which direction you should take. We spoke to two HVAC experts for their insights on the obvious and not-so-obvious signs of air conditioning repairs versus replacement, so you always know what to look for.

Key takeaways

Some AC problems can be easily and affordably remedied. For example, if your unit blows warm air, it likely means it's time for a refrigerant recharge, which costs $100 to $500.

If your AC unit is over 10 years old, out of warranty or needs frequent repairs, it may be time to replace it.

When in doubt, follow "the $5,000 rule." Multiply your HVAC's age by the repair cost. If the result is more than $5,000, replacement is the best option.

Signs you need to repair or replace your air conditioner

If you notice any of these signs in your AC unit, here’s how to tell whether it warrants repair or replacement.

AC unit is constantly running

Not every constantly running AC unit warrants replacement, unless it’s old and has a history of frequent repairs. Sometimes, minor issues like leaks or damaged coils can cause persistent running.

Refrigerant is leaking from your AC unit

Refrigerant leaks are another issue that can result in either a repair or replacement, depending on how severe the leak is. Refrigerant leaks can cause higher energy bills, higher humidity levels within the home and water damage, which leads to other repair costs.

If you suspect your AC unit is leaking, schedule a consultation with a technician to evaluate the repair cost before deciding whether to upgrade it.

Warm air is coming from your AC unit

If warm air is coming from your AC unit, odds are you need more refrigerant or your coils are dirty and clogged. You can turn your system off and clean the clogged or dirty coils yourself, or you can hire an HVAC technician to do it for you.

A refrigerant recharge, where the hired technician refills refrigerant used to cool the air that comes through your home’s HVAC system, costs $100 to $500, depending on the type of refrigerant.

You hear unusual noises when your AC is running

Running AC units are typically quiet, so if you notice clicking, buzzing, banging or other strange noises, your system needs an inspection. Sometimes, sounds from an AC unit mean a moderate issue, like loose parts or faulty compressors, but it can also mean a more severe problem, like motor issues or high pressure your system is under.

Your energy bills have increased

It’s normal for your energy bills to increase slightly when the seasons change. However, if your bills have skyrocketed, that’s a significant indicator that your AC unit might have an efficiency problem.

Start by changing your air filter, double-checking your thermostat settings and ensuring there are no gaps around the house before scheduling a consultation with a technician. Sadly, if these maintenance preventatives don’t decrease your energy bills, it’s time for a complete replacement.

When should you repair vs. replace your air conditioner?

Observe your system’s history to decide if a new unit will serve you well. Here are a few factors to consider when determining whether or not to repair or replace your air conditioner.

Age of your AC unit

Our experts agree that if your system is still relatively new (less than 10 years old), repairs will be a much better investment for the time being.

“I think it’s crucial to assess the age of your AC unit first,” said Justin Bohannon, expert technician and owner of Tech-on-Deck Heating, Air & Electric. “If [the air conditioner] is over 10 to 15 years old, replacement is often more cost-effective. I’ve seen many systems where the cost of repairs exceeded 50% of the cost of a new unit, and in those cases, replacement was the better choice.”

Cost of repairs

AC repairs are the wallet-friendly route unless your unit — new or old — needs a repair estimated to cost over a thousand dollars. One general rule HVAC pros follow that helps determine whether a repair or replacement is warranted is the “$5,000 rule.”

“This rule suggests multiplying the equipment’s age by the repair cost. If the result is more than $5,000, then replacement is usually the better option,” said HVAC technician and owner of Air Conditioner Lab Josh Mitchell.

For example, let’s say your HVAC unit is seven years old, and you need to replace the compressor for $2,800. 7 x $2,800 = $19,600, so in this case, replacing your HVAC unit would be the better option financially. If you have a unit that’s 12 years old and you have a fan motor that needs to be replaced for $350, 12 x 350 = 4200, so opting for the repair would make more sense.

Expired warranty

The standard HVAC warranty typically comes with new purchases and lasts five to 10 years. In these active years, any repairs that meet warranty requirements are covered by your manufacturer, but once the warranty expires (if you don’t extend it), you are responsible for the costs associated with your unit. Depending on what’s wrong with your unit when your warranty expires, it might be worth updating to a new unit if the cost difference is manageable.

History of repairs

While occasional air conditioner repairs are expected, a system requiring constant maintenance is not normal. In extreme cases, all the repairs will add up over time and might cost you the same as a new unit. Plus, having a system that consistently gives you issues means you can’t rely on it.

The peace of mind alone may warrant a new system. And while no set number for repairs indicates it’s time to throw in the towel and upgrade systems, Bohannon said looking at the overall expenses from your repairs is the better way to evaluate your current standing. “I’ve seen many systems where the cost of repairs exceeded 50% of the cost of a new unit, and in those cases, replacement was the better choice,” he said.

Lower or decreased efficiency

Air conditioning efficiency is a big deal. Not only do more efficient systems do a better job keeping your house comfortable year-round, but they also have a direct impact on the cost of your energy bills.

“If your system has decreased efficiency, your energy bills are likely higher, making replacement more appealing,” said Mitchell. While it’s possible to repair parts to a unit struggling with efficiency, consider your unit’s age and other factors that may indicate it’s a better investment to go for a total replacement.

Other than high energy bills, other signs that indicate your HVAC system has become less efficient could be uneven temperatures or constant running time.

Cost to repair vs. replace your air conditioner

Air conditioner repair and replacement costs will vary based on several factors. Below is a breakdown of the average cost ranges for common repair costs or full replacements.

Common AC repair costs

AC repair costs homeowners an average of $350, with low-end repairs costing between $125 and $150 and higher-end repairs costing around $1,500. These prices can increase after you factor in labor costs. Below is a chart detailing the common AC repairs and their average price range.

Average cost range
Circuit board

$130 - $650

Compressor replacement

$1,200 - $2,800

Evaporator coil replacement

$600 - $2,000

Fan motor

$150 - $500

Leak repair

$125 - $1,600

Refrigerant recharge

$150 - $500

Cost to replace an air conditioning system

Below is a chart detailing the average cost range of new unit purchases.

Average cost range
Central AC

$2,500 - $7,500

Ductless mini-splits

$2,000 - $14,500

Portable AC

$134 - $800

Window AC

$150 - $900

Source: The Home Depot and Lowe’s (Costs do not include installation labor.)

Central AC is the most popular type since it keeps the house comfortable and doesn’t disrupt room aesthetics like the other types do. However, window and portable AC units have significant price differences from central and ductless mini splits since they’re smaller systems and don’t require extensive installation.

How to increase the lifespan of your air conditioner

The best way to increase the lifespan of your air conditioner is to stick to a preventative maintenance routine. “I always advise regular maintenance, like changing filters every one to three months and scheduling annual professional check-ups. Simple steps like keeping your outdoor unit clean and ensuring proper insulation can significantly extend the life of your HVAC system,” Bohannon said.

Other than changing out the filters and scheduling professional check-ups, here are things you can do to preserve the longevity of your air conditioner:

  • Clean air ducts
  • Remove debris from your outdoor unit
  • Place your outdoor unit in a shaded area (if possible)
  • Upgrade to a smart thermostat

When should you call a professional to fix your AC?

Our experts recommend calling an HVAC professional at the first sign of trouble to determine your problem before it becomes more costly. Scheduling routine check-ups twice a year should help in the early identification of possible problems. Still, if you start noticing electrical issues, leaks or higher energy bills between visits, it’s time to call the pros. You should also contact a technician if you’ve tried to resolve the issue on your own and the problem remains.

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