If your furnace is nearing the end of its lifespan and your air conditioner is beginning to show signs of wear and tear from years of operation, like most homeowners, you're likely asking if it makes sense to replace your heating and cooling system at the same time.
More often than not, if your furnace is being replaced and your air conditioner was installed over 15 years ago (or vice versa), the answer is yes—but this isn't always the case.
Replacing your furnace and air conditioner together can save you thousands in separate installation costs, drastically improve energy efficiency - dropping your utility costs to all time lows, reduce or eliminate future HVAC repair costs, and ensure your HVAC system operates as a properly matched system. However, there are absolutely situations where replacing only one system may be the better financial decision.
In this guide, we'll explain the advantages, disadvantages, and cost considerations of replacing your furnace and air conditioner together so you can make a decision that keeps your home comfortable regardless of the season.
Why Metro Detroit Homeowners Consider Replacing Both Systems Together
Most HVAC systems, your furnace and air conditioner in particular, are designed to work together as matched equipment.
Your furnace and air conditioner share important components, including:
Blower motor
Air distribution system - Ductwork
Thermostat controls
Furnace control board
When one system significantly outlasts the other, efficiency and performance can suffer, and in the older neighborhoods of Grosse Pointe, Royal Oak, Clawson, and the surrounding areas, sometimes the worst happens and one failing system damages the other
It's for this reason that when one system is already nearing replacement age, we often recommend for homeowners to upgrade both systems at once.
Average Lifespan of a Furnace vs Air Conditioner
Gas Furnace
Typical lifespan: 17–20 years
Central Air Conditioner
Typical lifespan: 12–18 years in high humidity high temperature environments such as the southern United States
Typical lifespan: 17–22 years here in Southeastern Michigan
While regular preventative maintenance can help to extend the lifespan of your heating and cooling equipment, just like anything mechanical, your HVAC system is prone to run into failures with enough time and use. If both systems are more than 14-15 years old, replacing them together is often the best long term investment for keeping your furnace and AC repair costs low, minimizing your energy costs, and your home as comfortable as possible.
Replace One System vs Replace Both
Factor | Replace One | Replace Both |
Upfront Cost: | Lower | Higher |
Efficiency: | Moderate | Highest |
Warranty Coverage: | Partial | Complete |
Future Repair Risk: | Higher | Lower |
Equipment Matching: | Not Always | Yes |
Benefit #1: Higher Energy Efficiency
One of the biggest advantages of replacing both systems together is the increased efficiency that comes from a modern day furnace and air conditioner combination.
Modern HVAC systems are engineered to work together as matched equipment, allowing for exceptionally high efficiency features, and features that work to keep your household more comfortable than ever before.
A new high-efficiency air conditioner connected to an older furnace rarely achieves its full performance potential.
Matched systems often provide:
Better airflow to hard to reach rooms
Improved humidity control and dehumidification options
Lower energy consumption - lower utility costs
More even & consistent temperatures - improved home comfort
Benefit #2: Lower Long-Term Cost
Although replacing both systems requires a larger upfront investment, the investment usually pays itself off within the first 10 years of owning your new system, especially if upgrading from a lower efficiency HVAC equipment.
Benefits include:
Fewer service calls & required repairs
Reduced or eliminated repair expenses
Complete warranty coverage
Lower utility bills
The cost of two separate visits for a furnace installation and an AC installation will almost always be thousands more expensive than installing both systems in a single visit. It's for this specific reason that if one system is 14-15 years old at the time of the other system's replacement, replacing both is generally the recommended option.
Benefit #3: Better Comfort Throughout Your Home
Anyone who lives in Southeastern Michigan can speak on the wild climate shifts we deal with throughout the year. While bitterly cold winter seems to last the majority of the year, the summer in Metro Detroit seems to get warmer every year!
Most Metro Detroit Homeowners are all to familiar with:
Uneven temperatures
Hot upstairs rooms
Humidity problems
Poor airflow through vents
A complete HVAC system replacement allows your contractor to properly size and configure the entire system for your home's needs, tailoring airflow, humidity, and heating and cooling capacity to your specific household and home layout. This almost always results in a night and day difference for the overall comfort in your home.
When Replacing Both Systems Makes the Most Sense
Replace Both If:
✔ Furnace & Air Conditioner are 14+ years old
✔ Major repairs are needed
✔ Energy bills continue increasing
✔ You plan to stay in the home long-term
✔ You want maximum efficiency and comfort
When Replacing Only One System Makes More Sense
Sometimes replacing a single component is the best decision you can make.
Replace Only the AC If:
Furnace is less than 10 years old
Furnace is operating efficiently
Furnace has no major repair history
Furnace has receive regular maintenance
Replace Only the Furnace If:
Air conditioner is relatively new
AC performance remains excellent
Cooling system is still under warranty
You have an AC that uses R410 refrigerant
A qualified HVAC contractor can help to determine whether your existing equipment remains compatible with a new system, but most systems can be designed to work with one another!
How Much Can You Save By Replacing Both Together?
While actual savings vary from system to system, you're guaranteed to save money on:
Reduced labor costs
One single installation visit
Combined equipment rebates
Lower financing costs
Improved energy efficiency
Most manufacturers and utility providers offer incentives when homeowners install complete matched HVAC systems.
Need Help Deciding?
A professional system evaluation can help determine whether replacing one system or both systems is the best investment for your specific home. Reach out today for a free estimate!
What About Heat Pumps?
Thanks to the constantly improving equipment of the HVAC industry, along with incentives and benefits that can't be offered by a standard air conditioner, a heat pump installation may be worth considering during a complete HVAC system installation, or even a stand alone air conditioner replacement!
Modern cold-climate heat pumps can:
Provide heating and cooling
Improve efficiency beyond a standard air conditioner
Reduce overall energy consumption
Qualify for additional incentives
Unsure if a heat pump would be a good fit for your home? Reach out the the experts today!
Signs Your HVAC System Is Ready for Replacement
Don't wait for the dreaded midseason breakdown! It might be time to consider a replacement if you notice:
Frequent breakdowns
Rising utility bills
Uneven temperatures
Excessive humidity
Strange noises
Expensive repair recommendations
If several of these symptoms sound familiar, or your finding yourself having to seek AC repair or furnace service on a yearly basis, it's likely time to start looking towards an upgrade!
Why Michigan Homeowners Trust WeatherWise
WeatherWise Heating & Air Conditioning helps homeowners throughout Oakland County, Macomb County, and Wayne County Michigan make informed decisions when it comes to replacing their heating and cooling systems.
Whether you're replacing a furnace, upgrading an air conditioner, or considering a complete HVAC system upgrade, we understand better than most that it's a big decision deciding what will heat and cool your family for the next 20 years! Our team is proud to offer tailored options fit perfectly for your household, and can help you choose the right solution for your family's needs and budget!
Replacing your furnace and air conditioner at the same time isn't always necessary, but it is often the most cost-effective long-term solution when both systems are approaching the end of their lifespan.
A matched HVAC system can improve efficiency, reduce future repair expenses, and make your home more comfortable than you ever thought possible.
If you're unsure whether replacing one system or both makes sense, reach out to the pros today!
