Should You Replace Your AC and Furnace Together?
Yes, it’s often better to replace your AC and furnace together. When both systems are aging, replacing them simultaneously can save you money on installation costs, ensure optimal system compatibility, improve energy efficiency, and prevent future disruptions. However, if one system is significantly newer than the other or your budget is limited, replacing only the failing unit might make more sense.
Benefits of Replacing AC and Furnace Together
Replacing your AC and furnace at the same time comes with several advantages. Let’s look at why many homeowners choose this option.
Cost Savings on Installation
When you replace both systems together, you only pay for labor once. HVAC technicians charge for their time, and installing both units in one visit is more efficient. You can save between $500 to $1,000 on labor costs alone.
The technicians will already be there with their tools and equipment. They won’t need to make two separate trips to your home. This means you pay for setup and cleanup just once.
Matched System Performance
New AC units and furnaces are designed to work together as a matched system. When both parts are new, they communicate better and share components like the blower motor.
A matched system runs more smoothly and efficiently. The parts work in harmony instead of fighting against each other. This means better comfort for you and less strain on the equipment.
Consistent Warranty Coverage
When you install both systems at once, your warranty coverage starts at the same time. This makes it easier to keep track of when your protection ends.
Many manufacturers offer better warranty terms for complete system replacements. You might get extended coverage or additional benefits that wouldn’t be available when replacing just one unit.
When to Replace Both Systems at Once
There are certain situations when replacing both your AC and furnace makes the most sense. Here are the key scenarios to consider.
Similar Age of Equipment
If both your AC and furnace are getting old, replacing them together is smart. Most furnaces last 15-20 years, while AC units typically last 10-15 years.
When both systems are approaching the end of their useful life, replacing them together prevents the hassle of another replacement project soon. If your furnace is 15 years old and your AC is 12, it makes sense to do both at once.
Frequent Repairs Needed
When both systems need frequent repairs, it’s a sign they’re wearing out. If you’re calling for service multiple times a year, replacement might be more cost-effective.
Repair costs add up quickly. If you’ve spent more than $500 on repairs for either system in the past two years, replacing both units could save money in the long run.
Major Component Failure
If a major component fails in one system, it might be time to replace both. For example, if your AC’s compressor fails or your furnace’s heat exchanger cracks, these expensive repairs might not be worth it on older systems.
These major repairs often cost 50% or more of a new system’s price. When facing such a repair on an aging system, it’s usually better to put that money toward new, more efficient equipment.
When Replacing One System Makes More Sense
Sometimes, replacing just one system is the better choice. Here are situations when you might want to replace only your AC or furnace.
Significant Age Difference
If one system is much newer than the other, replacing only the older unit makes sense. For example, if your furnace is 18 years old but your AC is only 3 years old, just replace the furnace.
A good rule of thumb is: if one system is less than 7 years old and working well, keep it and just replace the failing unit. The newer system still has many years of service left.
Budget Constraints
Replacing both systems costs more upfront. If your budget is tight, replacing only the failing unit might be your only option right now.
A new complete HVAC system can cost $8,000 to $15,000. If that’s not affordable, replacing just the AC ($4,000-$8,000) or just the furnace ($3,000-$7,000) spreads out the expense over time.
Different Seasonal Timing
Sometimes, one system fails during its peak season. If your AC breaks in summer, you might need to replace it immediately without waiting to also replace the furnace.
Emergency replacements sometimes don’t allow for the planning needed to replace both systems. In these cases, focus on fixing the immediate problem first.
Cost Comparison: Together vs. Separately
Understanding the financial impact of replacing systems together versus separately helps you make a better decision.
Upfront Costs vs. Long-term Savings
Replacing both systems at once costs more upfront but saves money over time. Here’s a simple comparison:
| Replacement Option | Typical Cost | Labor Savings |
|---|---|---|
| AC and Furnace Together | $8,000-$15,000 | $500-$1,000 |
| AC Only | $4,000-$8,000 | $0 |
| Furnace Only | $3,000-$7,000 | $0 |
When you add up separate installations, you’ll spend more in total than if you had done both at once. The difference can be $500-$1,000 or more.
Installation Efficiency
Installing both systems at once is more efficient for the HVAC company. They can complete the work faster and with fewer complications.
The technicians only need to set up their workspace once. They can also plan the entire installation as one project, which reduces the chance of mistakes or compatibility issues.
Avoiding Future Disruption
Replacing both systems means you won’t need another HVAC installation for many years. This saves you from the disruption of having workers in your home again soon.
Each HVAC installation typically takes 1-3 days and requires you to be home. Doing it all at once means less total disruption to your life and schedule.
System Compatibility Considerations
Modern HVAC systems are designed to work together. This compatibility affects performance, efficiency, and even warranty coverage.
Shared Components
Your AC and furnace share several important components. The most important is the blower motor, which moves air for both heating and cooling.
When you replace just one unit, the new system must work with the existing blower. This can lead to mismatched performance. A new high-efficiency AC might not reach its full potential when paired with an older furnace blower.
Technology Matching
Newer HVAC systems use advanced technology that works best when matched. Variable-speed motors, smart thermostats, and zoning systems all perform better when the AC and furnace are designed to work together.
For example, a new variable-speed furnace paired with an older single-stage AC won’t deliver the full comfort benefits of variable operation. The system can only work as well as its oldest component allows.
Manufacturer Recommendations
HVAC manufacturers design their systems to work together. Many even offer special pricing or extended warranties for complete system replacements.
Some manufacturers may limit warranty coverage if you mix new and old equipment. Always check the warranty terms before deciding to replace just one component of your HVAC system.
Energy Efficiency Benefits
One of the biggest advantages of replacing both systems together is improved energy efficiency. This translates to lower utility bills and better comfort.
SEER and AFUE Ratings
New AC units are measured by their SEER rating (Seasonal Energy Efficiency Ratio). Higher SEER means better efficiency. Today’s models range from 14 to 26 SEER, compared to old units that might be 10 SEER or less.
Furnaces are rated by AFUE (Annual Fuel Utilization Efficiency). Modern furnaces offer 80% to 98% AFUE, while older models might be 70% or lower. Replacing both systems gives you the highest possible efficiency ratings.
Reduced Utility Bills
When you replace both systems with high-efficiency models, your energy bills can drop significantly. Many homeowners report saving 20-40% on their heating and cooling costs.
These savings add up over time. If you spend $2,000 yearly on heating and cooling, a 30% reduction saves you $600 each year. Over the 15-year life of the system, that’s $9,000 in savings.
Environmental Impact
More efficient systems use less energy, which reduces your carbon footprint. They also use newer refrigerants that are better for the environment than older types.
By replacing both systems at once, you maximize these environmental benefits. You’ll be doing your part to reduce energy consumption and greenhouse gas emissions.
Frequently Asked Questions
How do I know if my AC and furnace need replacement?
Look for these signs: your equipment is over 15 years old, your energy bills are rising, repairs are becoming frequent, or your home isn’t comfortable despite the system running. Strange noises, uneven heating or cooling, and poor air quality are also warning signs.
Can I replace just the outdoor AC unit and keep my old furnace?
Yes, you can, but it’s not always ideal. The new AC might not work as efficiently with an old furnace. The blower motor in your furnace circulates air for both heating and cooling. If the motors aren’t matched, you won’t get the full efficiency benefits of your new AC.
Will replacing both systems increase my home’s value?
Yes! New HVAC systems are attractive to home buyers. According to the National Association of Realtors, you can recover about 85% of your HVAC investment when selling your home. Buyers prefer homes with newer, more efficient systems that won’t need replacement soon.
How long does it take to install both an AC and furnace?
A complete system replacement typically takes 1-3 days, depending on the complexity of your home and any ductwork modifications needed. Replacing just one unit might take 4-8 hours, but you’d need to schedule another installation later for the second unit.
Can I finance a complete system replacement?
Most HVAC companies offer financing options. Many provide special financing for complete system replacements, sometimes with better terms than for single-unit replacements. Some utilities and government programs also offer rebates or incentives for upgrading to more efficient systems.
What size systems do I need for my home?
The right size depends on your home’s square footage, insulation, window quality, climate, and other factors. A professional should perform a “Manual J” load calculation to determine the correct size. Never just replace with the same size without this assessment, as your old units might have been incorrectly sized.
Is it worth paying extra for high-efficiency models?
For most homeowners, yes. Higher efficiency models cost more upfront but save money over time through lower energy bills. If you plan to stay in your home for at least 5 years, the energy savings typically offset the higher initial cost.
How often should HVAC filters be changed?
Basic filters should be changed every 1-3 months. Higher-quality filters might last 3-6 months. Check your filter monthly and replace it when it looks dirty. Regular filter changes help your new system run efficiently and last longer.
Should I replace my ductwork when replacing AC and furnace?
Not always, but it’s worth inspecting. If your ductwork is over 15 years old, has leaks, or is poorly designed, replacing it along with your HVAC system makes sense. Proper ductwork can improve efficiency by 20% or more.
What maintenance will my new systems need?
New systems should be professionally maintained once a year for the AC and once for the furnace. This typically costs $80-$150 per visit. Regular maintenance keeps your warranty valid and helps prevent breakdowns.
Ready to make the best decision for your home’s comfort and your wallet? Contact Strickland HVAC today for a consultation. They can assess your current systems, discuss your options, and help you decide whether replacing your AC and furnace together is right for your situation. Don’t wait until one system fails completely – plan ahead and stay comfortable year-round!