The decision to replace a gas furnace and air conditioner involves evaluating upfront costs, efficiency gains, installation variables, and long-term savings. This guide explains the average cost of a new gas furnace and air conditioner, key factors that influence pricing, financing options, and tips to get the best value for homeowners across the United States.
| Component | Typical Cost Range (Installed) | National Average |
|---|---|---|
| Gas Furnace (Unit + Install) | $2,500 – $7,500 | $4,500 |
| Central Air Conditioner (Unit + Install) | $3,000 – $8,000 | $5,000 |
| Combined Furnace + AC Replacement | $6,000 – $15,000 | $9,500 |
| High-Efficiency or Two-Stage Systems | $10,000 – $20,000+ | — |
How Average Costs Are Calculated
Average costs for a new gas furnace and air conditioner reflect the combined price of equipment, labor, permitting, ductwork modifications, disposal of old units, and any additional components such as thermostats or electrical upgrades.
Equipment quality and efficiency ratings (AFUE for furnaces and SEER for air conditioners) are primary drivers of unit price, while regional labor rates significantly affect installed costs.
Breakdown Of Typical Cost Components
Equipment Costs
Furnace prices vary by brand, capacity, and AFUE rating; basic single-stage units cost less while two-stage or modulating furnaces with higher AFUE ratings cost more. Central air conditioner units vary by SEER rating and compressor type (single-stage, two-stage, inverter-driven).
Installation Labor
Labor is charged based on complexity and local market rates. Simple like-for-like swaps in homes with existing compatible ductwork cost less than systems requiring extensive duct modification or new refrigerant line sets.
Permits, Inspections, And Disposal
Most municipalities require permits and inspections. Disposal of the old furnace and AC, refrigerant recovery fees, and permit costs typically add several hundred dollars to the invoice.
Ductwork, Electrical, And Structural Work
Leaky or undersized ductwork can reduce system efficiency and often requires sealing or replacement. Electrical upgrades for higher-efficiency equipment or new AC units with larger electrical draws may increase costs.
Average Costs By System Type And Efficiency
National averages shift with system type and efficiency. Homeowners selecting higher-efficiency models pay more upfront but save on energy bills over time.
| System Type | Installed Cost Range | Notes |
|---|---|---|
| Basic Furnace (80% AFUE) + Basic AC (13 SEER) | $6,000 – $9,000 | Lower upfront cost, lower efficiency |
| Mid-Range Furnace (90-95% AFUE) + Mid AC (14-16 SEER) | $8,000 – $12,000 | Good balance of cost and efficiency |
| High-Efficiency Furnace (95%+ AFUE) + High AC (17+ SEER) | $10,000 – $20,000+ | Best long-term savings; often two-stage/modulating |
Regional Variations In Cost
Installation rates, climate, and local regulations influence regional differences in the average cost of a new gas furnace and air conditioner. Labor tends to be more expensive in metropolitan areas and on the coasts compared with rural regions.
Climate affects system sizing: colder northern states may require higher-capacity furnaces, while hot southern states prioritize robust air conditioning capacity—both affecting equipment cost.
Sizing, Load Calculations, And Why They Matter
Accurate system sizing via Manual J load calculations ensures the furnace and air conditioner are properly matched to the home. Oversized systems short-cycle, increasing wear and reducing efficiency; undersized systems struggle to maintain comfort.
Professional load calculations typically add modest cost but substantially improve system performance and longevity.
Energy Efficiency Ratings And Long-Term Savings
Furnace AFUE (Annual Fuel Utilization Efficiency) indicates the percentage of fuel converted to heat. An 80% AFUE furnace wastes 20% of fuel, while a 95% AFUE furnace wastes only 5%.
AC efficiency is measured by SEER (Seasonal Energy Efficiency Ratio). Higher SEER ratings mean lower energy consumption during cooling season. Choosing higher-efficiency systems raises upfront cost but can reduce utility bills significantly.
Incentives, Rebates, And Tax Credits
Federal, state, and local incentives can lower the effective cost of a new gas furnace and air conditioner. Programs vary by location and often target high-efficiency systems or those combined with renewable technologies.
Utilities may offer rebates for ENERGY STAR-rated equipment. Homeowners should check with local utilities, the Database of State Incentives for Renewables & Efficiency (DSIRE), and federal tax credit updates.
Common Upgrade Options And Their Costs
Smart Thermostats
Smart thermostats improve comfort and can yield energy savings through learning algorithms and remote control. Typical installed cost ranges from $150 to $400, depending on features and professional setup.
Air Purification And Ventilation
Upgrades such as HEPA filtration, UV lamps, or energy recovery ventilators add to indoor air quality and can cost from a few hundred dollars to several thousand dollars installed.
Zoning Systems
Zoning with multiple thermostats improves comfort and efficiency in larger homes but adds complexity. Zoning systems, dampers, and controls typically add $1,500 to $4,500 or more.
Financing And Payment Options
Many HVAC contractors offer financing plans, including low-interest loans or deferred-payment promotions. Home equity loans and energy-efficient mortgages may cover replacement costs as well.
Compare APRs, loan durations, and total repayment when evaluating financing options to ensure the monthly payment aligns with projected energy savings.
How To Get Accurate Quotes And Avoid Surprises
Request multiple written quotes and ensure each includes a detailed breakdown of equipment, labor, warranty terms, and any contingencies. Avoid quotes lacking scope details or those that significantly undercut competitors without explanation.
Insist on a written estimate tied to a Manual J load calculation and equipment specifications. Confirm whether permits, disposal, and startup checks are included.
Warranty Considerations
Warranty coverage varies by manufacturer and contractor. Factory warranties may cover parts for a set period, while extended warranties and labor guarantees may be available for purchase.
Register new equipment with the manufacturer and retain proof of professional installation to protect warranty rights.
Signs It’s Time To Replace Both Furnace And AC
- Equipment Age: Furnaces older than 15-20 years and AC units older than 10-15 years often approach end-of-life.
- Rising Repair Frequency: Repeated repairs and rising repair costs suggest replacement is more cost-effective.
- Poor Efficiency And Comfort: Uneven heating/cooling, high energy bills, and frequent cycling indicate replacement benefits.
Practical Cost-Saving Tips
- Consider replacing both units together to reduce combined labor and ensure matched equipment performance.
- Look for seasonal promotions in spring and fall when HVAC demand is lower.
- Bundle upgrades like thermostats or duct sealing with replacement to negotiate better pricing.
- Take advantage of rebates and tax incentives for high-efficiency models.
Sample Cost Scenarios
Scenario 1: A modest 1,800 sq ft home in a temperate region replacing an 80% furnace and 13 SEER AC with mid-range 95% AFUE furnace and 16 SEER AC might expect to pay around $8,500–$11,000 installed.
Scenario 2: A larger 3,000 sq ft home upgrading to high-efficiency equipment with zoning, ductwork improvements, and a smart thermostat could see costs of $15,000–$22,000.
Questions To Ask Potential Contractors
- Will you perform a Manual J load calculation and provide the report?
- What are the exact brands, models, and efficiency ratings of the proposed units?
- Is the price all-inclusive (permits, disposal, startup, refrigerant recovery)?
- What warranties are included for parts and labor?
- Are installers NATE-certified or similarly qualified?
How Replacement Impacts Home Value And Comfort
Replacing a failing HVAC system improves comfort, lowers operating costs, and can increase home value and marketability. Buyers often view newer, efficient systems as a selling point.
Energy efficiency and indoor air quality upgrades add measurable appeal for energy-conscious buyers and can factor into appraisal values depending on the market.
Resources For Further Research
Homeowners should consult manufacturer websites, ENERGY STAR, local utility rebate pages, DSIRE, and third-party reviewer platforms for contractor evaluations. Checking multiple sources ensures a well-informed purchase decision.
For complex projects, consider seeking a second opinion from a certified HVAC engineer or an independent energy auditor.