Replacing Your Furnace and AC at the Same Time Can Have Big Cost Benefits

Leah Lopez Cardenas
Updated September 8, 2022
Mother and little daughter snuggling on the couch
Photo: BullRun / Adobe Stock

If you can replace your furnace and AC at the same time, it can be a genius cost-saving measure

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A good HVAC system should keep you cozy and warm in the winter and cool in the summer. However, if your air conditioner has quit, but the furnace still works (or vice versa), it's tempting to just replace the appliance that’s broken. But replacing both your heating and cooling systems—even if one is still working—can save energy and money over the long term. 

Read on to learn about the clear advantages and potential setbacks for your home and wallet if you replace a furnace and AC together.

Reasons to Replace a Furnace and Air Conditioner at the Same Time

Two new systems can equal one comfortable home. Here are some of the advantages of installing a new furnace and air conditioning system at the same time:

HVAC Energy Efficiency

The heating and air conditioning systems manufactured today are highly efficient and use much less energy than systems built just 10 to 15 years ago. You can easily compare the efficiency of different air conditioning systems as you research by checking the Seasonal Energy Efficiency Ratio (SEER) rating. The higher the SEER, the less energy they use and the lower the cost to operate.

Newer systems have a SEER number of at least 13, the minimum government standard for cooling systems. However, that minimum standard will change in 2023 to no less than 14 SEER for residential systems in the northern part of the United States and 15 SEER in the southern part of the United States. So if you’re going to get a new AC soon, you’ll need a unit with one of these higher SEER ratings to ensure you don’t have another replacement on your hands soon.

The rating for furnaces is the annual fuel utilization efficiency (AFUE), a measure of seasonal performance. In general, an AFUE of 90% or higher is recommended for a new, efficient furnace system. Boilers and heat pump systems will have a slightly different recommended number.

On average, a modern furnace will last 15 to 20 years, and a central air conditioning system will last 12 to 15 years, depending on the quality and efficiency of the equipment.

Furnace and AC Performance

Mixing and matching a new system with an old, inefficient system could potentially decrease the lifespan of the new system you just invested in. By replacing just one part of your overall HVAC system, you effectively lower the performance of both appliances. When you couple a new, highly efficient system with an older one, you won't utilize the new technology to its full potential.

Also, make sure you fully understand your warranty. In some cases, manufacturers are not obligated to honor warranties of new systems that are combined with older systems if they break down during the warranty period. Replacing both systems at the same time will ensure you have the protection of your warranty if you should need it.

Matched HVAC Systems Complement Each Other

A furnace system and central air conditioning system share the same air handler, also called a blower. A matched system with an efficient handler will allow both systems to operate properly, giving you the home comfort you need.

Heating and Air Conditioning Cost Savings Over Time

You'll save money with a matched system because all components work together for maximum efficiency over time. If repairs are necessary, both systems will be under warranty (and overall, new systems will require fewer repairs). The installation process will also tend to be less complicated and involved. For example, by replacing the air conditioner and waiting to replace the heating system, you will likely have to pay the cost for the heating installation later when it’s time to replace it, whereas installing them together will likely cost less total.

Reasons Not to Replace a Heater and Air Conditioner at the Same Time

Despite the many advantages of replacing a furnace and AC at the same time, it’s not the right choice for every homeowner. Here are some of the disadvantages of installing a totally new HVAC system, even if one appliance isn’t necessarily malfunctioning:

Your System Is Fairly New and Works Fine

If your furnace and air conditioner are only a few years old and nothing seems to be wrong with them, there isn’t really any reason to replace a fully-functioning appliance. However, if your appliance isn’t working as well as expected, here’s a good rule to follow: If a furnace or AC repair will cost more than half the price of buying a new one and the unit is more than six years old, it’s probably best to replace rather than repair.


If you can’t swing it in your budget to afford a heater or AC replacement along with the appliance that’s broken, don’t force yourself into a sticky financial situation.

Average Cost of a New Furnace and AC Unit Put in at the Same Time

A new furnace costs around $5,500 on average, with a typical range between $2,600 and $6,400. The cost to install a new AC unit is between $3,800 to $7,500 on average. However, the cost of a new HVAC system together costs $7,500 on average, usually somewhere in the range of $5,000 to $12,500. 

You could save money by having a contractor install both appliances all at once. Sometimes you can even snag a deal by buying a heater and air conditioner at the same time as a pair versus buying them separately at different times.

Factors That Affect the Cost to Replace the AC and Furnace at the Same Time

Several factors impact the cost of replacing your HVAC system, including the type of HVAC system you get, the size of the unit you need, the brand of appliances you buy, and who you hire to do the job.

Type of HVAC System

There are four types of HVAC systems, including split systems, duct-free systems, hybrid systems, and packaged heating and air systems. The typical cost ranges for each are:

  • Split systems: $3,800–$7,500

  • Duct-free systems: $2,000–$14,500

  • Hybrid systems: $2,500–$10,000

  • Packaged heating and air systems: $10,000–$14,000


Luxury living room with high ceiling
Photo: bmak / Adobe Stock

The square footage of your house will determine what size furnace and air conditioner you need to heat or cool your space efficiently. A local HVAC company can help you determine what size you need exactly by doing a load calculation.


An HVAC system costs about $4,750 on average, but the brand you buy can change this number. For example, brands like Amana or Coleman tend to come in the lower end of the spectrum at $3,000, while brands Trane and York are often $6,000 or more.

Contractor You Hire

The cost of labor to install a new HVAC system is around $1,500 alone, but this number can fluctuate a bit from company to company. Request a quote from a few different local heating and cooling contractors to get an idea of what you’ll spend and compare your options.

Frequently Asked Questions

If both your furnace and AC unit are more than a decade old, it may be a good idea to replace both of them. However, your furnace can last up to three decades, and your air conditioner can typically last up to 15 years, so consulting with a pro before deciding to replace both of them is best. If it’s before that time limit for each, you can fix many problems with repairs or just replace one.

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