It’s finally summer and the first true scorcher of the year is on your doorstep. To keep your home comfortable (and habitable), you do what anyone would: reach for the thermostat to seek the reliable, cool relief of your air conditioning unit. However, you’re shocked to discover that your vents are blowing warm air or even not blowing at all!

A busted AC unit is no joke and can make for a miserable home. Thankfully, replacing your air conditioner is a manageable task if you know what steps to take. To offer you some guidance through the process, HomeLight sought advice from an HVAC expert and used their insight to create a simple checklist for restoring your cool air.

1. Note common “red flags” that indicate an issue

Short of hot air blowing out of your vents, there are a number of “red flags” that can give you an early warning that you’ve got a problem with your AC. Mark Dawson, COO of One Hour Heating and Air Conditioning, let us know some warning signs to look out for:

• Rattling: If you hear something knocking around inside of your AC unit, it’s likely that something has slipped through the grate covering your outdoor condenser. Small objects can make their way into your system and lead to other issues later on.
• Clanking or scraping: Sharp metal-on-metal sounds often mean that your AC unit has loose parts such as a fan blade that fell out of alignment or a loose pipe scraping up against another moving piece of the system.
• Squeaking or thumping on startup or shutdown: A good AC unit is relatively quiet, and any noise it does make should be consistent. Squeaks and thumps on startup or shutdown can indicate worn-out parts.
• Hissing: Loud hissing is often a sign that your system has air escaping from where it shouldn’t. Hissing from inside your walls could indicate leaky ducts while hissing from your filter might mean that the filter isn’t forming an adequate seal.
• Bubbling: If you hear bubbling coming from your AC unit, check for leaks in the refrigerant line. A leak in the refrigerant line that allows air inside can lead to major issues with your unit. Call an HVAC professional right away if you notice any bubbling sounds.

While not all of these issues mean that you need a new AC unit, they all indicate it’s time for unit maintenance. Warning signs that you need to replace your air conditioner unit entirely include:

• Your AC unit is getting old: The U.S. Department of Energy reports that AC units have an average lifespan of around 15 to 20 years. AC units in coastal areas only have an average lifespan of about 12 years due to the salty ocean air.

• Your energy bill is going up: An aging AC unit won’t work as efficiently as a new one, meaning that your energy bill will likely increase as your unit enters its twilight years.

• You’ve got humidity issues: A faulty AC unit can lead to poor humidity control in your home, resulting in dry indoor air in the winter and humid indoor air in the summers. Condensation on the inside of your windows, moisture around your vents, and mildew growth are all signs that your AC is nearing the end of its life.

2. Start saving — big time

HomeAdvisor, a company that connects customers with professionals and aggregates data from the resulting quotes, reports that the average cost to install a central air conditioning system is about $3,811 to $7,480.

This price fluctuates depending on a few different factors, including the specific AC unit you choose, the difficulty of the installation, labor costs in your market, and additional necessary work like ductwork repair. To get the best deal, you’ll need to learn more about your home’s needs and the options available to you.

3. Hire a professional to inspect the system

HVAC systems are complicated and, if you aren’t an HVAC professional yourself, it’s wise to seek out a professional who can inspect your system and home and let you know what you need to do to successfully replace your unit.

The average hourly rate for HVAC labor is $90 to $100. You can find HVAC technicians near you on websites like Angi that connect people with professional service providers. Always ask professionals for their experience and licenses before hiring them. You can also read recent client feedback on Yelp and other review sites.

4. Check for the condition of related systems

In some instances, the AC isn’t the main issue; another malfunctioning system in your home might be the root of the problem. If this is the case, restoring your AC could simply mean replacing your fuse box or thermostat.

Here are a few things to check up on before pulling the trigger on paying for a full AC replacement:

• Thermostat
• Furnace
• Transformer
• Fuse box
• Insulation
• Windows
• Door seals
• Ventilation ducts

5. Research replacement options

• Cooper & Hunter Ductless Mini Split AC/Heating System for $1,599 from Amazon
• Mr. Cool Gen-3 Ductless Mini Split Air Conditioner for $1,400 from Home Depot

Packaged unit

In a packaged central air conditioner, the evaporator, condenser, and compressor are located in one cabinet, which is typically located on a roof or on a concrete slab next to the home’s foundation.

These systems are cheaper to install but offer less zone control — typically leading to increased energy bills.

Two best-sellers include:

• Goodman 5 Ton Multi Position Air Conditioner Package Unit for $3,440 from AC Wholesalers
• ICP / EcoTemp Model 4 Ton Package AC Unit for $2,700 from Budget Air Supply

Rightsizing, or matching the size of your AC to your home, is also important. As Dawson points out:

“If your AC unit is too small, it will run constantly without ever properly cooling your home, gobbling up an excess of electricity while it’s at it. If you buy an oversized model, on the other hand, it will cycle on and off too frequently, leading to excessive wear and tear as well as inflated bills to cover cooling power that you don’t even need.”

6. Keep energy efficiency in mind for your replacement system

One benefit of replacing your air conditioner? You’ll likely upgrade to a more energy-efficient model, which is gentler on the earth and your utility bills.

Modern air conditioners seriously outperform older models. The best air conditioners on the market today use half as much energy to produce the same amount of cooling as models from the 1970s. Even when compared to air conditioners from just a decade ago, newer models can save you 20% to 40% of your cooling energy costs.

Dawson emphasizes that these savings are substantial considering the average household spends 40% of its energy budget on heating and cooling.

7. Get your system installed and enjoy your fresh, cool air

Once you’ve done all your due diligence, it’s time to pull the trigger. Find an experienced HVAC technician to install your new system. After the job is complete, switch your AC on, set the thermostat, and enjoy finally escaping from the summer heat.