How Much Does a Gas Furnace Cost? Prices, Installation, and Savings

Replacing or installing a gas furnace is a significant project with costs that vary widely by home, climate, and equipment choice. This guide breaks down gas furnace cost, what drives price differences, and how to estimate total budget, from equipment and labor to venting, ductwork, and rebates. It also offers tips to get accurate bids and reduce long-term operating costs.

What Drives Gas Furnace Cost

Gas furnace cost has two main parts: equipment (the furnace and accessories) and installation (labor and materials). Prices shift with furnace size, efficiency, brand tier, and job complexity.

Size (BTU Output): Larger furnaces cost more and may need bigger ducts or gas lines.
Efficiency (AFUE): High-efficiency condensing models cost more but burn less gas.
Features: Two-stage or modulating burners and ECM/variable-speed blowers add comfort and cost.
Installation Complexity: Venting, condensate drains, gas/electrical upgrades, and duct changes increase labor.
Home Type: Replacement in existing homes often costs more than new construction rough-ins.
Region and Labor Rates: Urban, coastal, and high-cost-of-living areas have higher labor costs.
Permits and Code: Inspections, seismic strapping, combustion air, and carbon monoxide (CO) safety can add scope.

National Averages And Price Ranges

Actual bids vary, but the ranges below reflect typical U.S. pricing for replacement projects by licensed contractors, including permit and basic accessories. Complex homes can fall outside these ranges.

Furnace Type	Typical Equipment Price	Typical Installed Cost	Notes
80% AFUE, Single-Stage	$1,300–$2,600	$3,800–$6,800	Non-condensing; simpler venting where allowed by code.
92–95% AFUE, Two-Stage	$1,900–$3,600	$4,800–$8,500	Condensing; requires PVC venting and condensate drain.
96–98% AFUE, Modulating/Variable-Speed	$2,800–$5,800	$6,500–$12,000	Top comfort; highest equipment and labor premium.
Complex Replacements	$3,500–$6,500	$9,000–$15,000+	Major duct, gas, or vent changes; tight spaces or code upgrades.

Most homeowners spend $4,500–$9,000 for a standard high-efficiency replacement without major duct modifications. Low bids may omit key items (permits, venting, commissioning) that affect safety and performance.

Sizing And AFUE Efficiency: How They Affect Price

Right-Sizing With Manual J

Furnace capacity is measured in BTU per hour (BTU/h) of output. Correct sizing uses a Manual J heat load calculation that considers climate, home size, insulation, windows, and air leakage. Oversizing leads to short cycling, noise, and uneven heat.

Home Size (Insulated, Typical)	Cold Climate Output	Mixed Climate Output	Warm Climate Output
1,200 sq. ft.	50,000–70,000 BTU/h	35,000–55,000 BTU/h	25,000–40,000 BTU/h
2,000 sq. ft.	70,000–100,000 BTU/h	50,000–75,000 BTU/h	35,000–55,000 BTU/h
3,000 sq. ft.	90,000–130,000 BTU/h	65,000–95,000 BTU/h	45,000–70,000 BTU/h

These are rough planning ranges; a contractor should verify with Manual J and duct design (Manual D). See ACCA Manual J for methodology.

AFUE And What It Means

AFUE (Annual Fuel Utilization Efficiency) measures how much fuel becomes useful heat. An 80% AFUE furnace delivers 80% of input energy as heat; a 96% unit delivers 96%.

80%: Lower equipment and vent costs; legal in many southern/mixed climates.
90–95%: Condensing; improved efficiency and comfort.
96–98%: Highest efficiency; often paired with variable-speed ECM blowers and sophisticated controls.

AFUE	Equipment Premium vs. 80%	Fuel Savings vs. 80%	Notes
92–95%	$400–$1,200	~10–19%	Requires PVC vent and condensate drain/neutralizer.
96–98%	$1,200–$3,000+	~20–22%	Top-tier controls, quieter, better humidity control with ECM.

Efficiency pays back faster in colder climates or where natural gas is expensive. In mild climates, comfort features may matter more than fuel savings alone.

Installation Variables That Change The Bid

Beyond the furnace, installation details can swing costs significantly. Here are common add-ons and typical price ranges.

Scope Item	Typical Cost Range	Why It Matters
Direct Vent PVC (Intake/Exhaust)	$400–$1,200	Condensing furnaces need new vent runs; length and wall/roof penetrations add cost.
Chimney Liner / Flue Resize	$500–$2,000	Required if other appliances remain on a masonry chimney or for code compliance.
Condensate Drain & Neutralizer	$150–$600	Protects plumbing from acidic condensate; may need pump if no gravity drain.
Gas Line Upsize/Extension	$200–$800+	Larger furnaces or long runs need bigger piping to maintain pressure.
Electrical Upgrade/Outlet	$150–$500	New disconnect, GFCI, or dedicated circuit per local code.
Duct Modifications	$300–$2,500	Transitions, plenums, or returns to match new cabinet size and improve airflow.
Filtration/IAQ Add-Ons	$250–$1,200	Media filter cabinets, UV, or air cleaners; improves air quality and furnace longevity.
Permits & Inspection	$100–$600	Required in most jurisdictions; ensures safety and code compliance.
Removal/Disposal	$100–$300	Old furnace haul-away and site cleanup.

Transparent, itemized bids help compare apples to apples and avoid change orders.

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Replacement, New Construction, And Fuel Conversion

Simple Replacement

Replacing a furnace like-for-like with compatible venting and ducts is the lowest-cost scenario. Expect $3,800–$8,000 for standard installs, with variability for size and features.

New Construction

In new homes, the furnace price may be similar, but rough-in labor is bundled with the HVAC system. Costs depend on total system design, zoning, and whether an AC coil or heat pump is paired.

Converting From Oil, Propane, Or Electric

Switching to natural gas can add substantial costs beyond the furnace. Budget for utility work and building upgrades.

Gas Service And Meter: Utility connection fees vary widely; some utilities subsidize. Trenching or street work can add $1,000–$5,000+.
Flue/Venting Changes: Oil-to-gas often needs a chimney liner or new PVC vent, $500–$2,000.
Electrical & Thermostat: May need new low-voltage wiring or smart thermostat, $150–$600.
Oil Tank Decommissioning: If applicable, $800–$3,000+, more for underground tanks.

Total conversion projects commonly run $6,500–$15,000+ depending on utility distance, permitting, and ancillary work.

Brand Tiers, Features, And Warranty

Brand alone is less important than proper design, installation, and commissioning. Still, brand tiers loosely align with features and pricing.

Tier	Typical Features	Installed Cost Range
Budget	80–92% AFUE, single-stage, PSC/ECM blower, basic controls	$3,800–$6,500
Mid-Tier	92–96% AFUE, two-stage, ECM variable-speed, improved sound and comfort	$4,800–$9,000
Premium	96–98% AFUE, modulating, fully variable blower, advanced diagnostics	$6,500–$12,000+

Most major brands offer similar tiered lines. Warranty terms typically run 10 years for parts with 20-year or lifetime heat exchanger coverage; labor coverage depends on the installer and extended warranty options.

Operating Cost And Payback

Fuel savings from higher AFUE depend on local gas prices, climate, and thermostat settings. The U.S. Energy Information Administration tracks prices; residential natural gas commonly ranges about $0.80–$1.80 per therm depending on region and season (EIA).

How To Estimate Annual Cost

One therm equals 100,000 BTU. Suppose a home needs 60 million BTU of delivered heat per winter.

At 80% AFUE, fuel input = 60M / 0.80 = 75M BTU = 750 therms.
At 96% AFUE, fuel input = 60M / 0.96 = 62.5M BTU = 625 therms.

If gas is $1.30/therm, the 96% unit saves (750 − 625) × $1.30 ≈ $162.50 per year. If the high-efficiency premium is $1,500, simple payback is about 9.2 years. Colder climates or higher gas prices shorten payback.

Gas Price ($/Therm)	Savings Per 100 Therms	Savings For 750→625 Therms
$0.90	$18	$112.50
$1.30	$26	$162.50
$1.80	$36	$225.00

Comfort matters too: Two-stage or modulating units often heat more evenly and run quieter, which some homeowners value beyond fuel savings.

Regional Price Differences

Home size, climate, codes, and labor rates produce regional cost patterns.

Northeast: Older homes, tight basements, and more chimney liners. Higher labor rates and permit costs.
Midwest: High demand for high-efficiency systems. Competitive markets with solid contractor density.
South/Southwest: More 80–92% units where code allows. Lower labor rates in some metros; simpler venting.
West Coast: Higher labor costs; stricter energy codes and permitting. Earthquake bracing may be required.

Weatherization incentives and utility rebates differ widely by state and utility, affecting net cost.

Rebates, Tax Credits, And Financing

Incentives change frequently and vary by location. Many utilities offer $100–$800+ rebates for high-efficiency furnaces and smart thermostats. Search the DSIRE database for programs by ZIP code.

Federal incentives have increasingly prioritized electric heat pumps and weatherization. Some gas furnaces may not qualify for federal tax credits depending on current law and efficiency tiers. Always verify eligibility with ENERGY STAR and the IRS Energy Efficient Home Improvement Credit pages before purchase.

Contractors may offer financing or on-bill options through utilities. Compare APR, term length, and prepayment penalties against personal loans or HELOCs.

Signs It Is Time To Replace

Modern furnaces typically last 15–20 years, sometimes longer with routine maintenance. Replacement becomes compelling when safety, reliability, or efficiency decline.

Frequent Repairs: If repairs exceed 50% of replacement cost or failures are recurring.
Heat Exchanger Issues: Cracks or corrosion are safety risks and often non-repairable.
Rising Gas Bills: Especially with older 70–80% AFUE units and poor ducts.
CO Alarms Or Soot: Shut down and call a pro immediately; address venting and combustion issues.
Parts Obsolescence: Older boards, inducer motors, or burners can be hard to source.

A pre-season tune-up with combustion analysis can reveal whether repair or replacement is more cost-effective.

How To Get An Accurate Quote

Well-scoped bids reduce surprises and improve comfort and efficiency.

Require Manual J And D: Load calculation and duct evaluation prevent oversizing and noise.
Get Three Itemized Bids: Include model numbers, AFUE, blower type, thermostat, venting, and accessories.
Ask About Commissioning: Static pressure, temperature rise, combustion analysis, and CO safety tests.
Confirm Permits And Inspections: The contractor should handle and provide proof.
Clarify Warranties: Parts, labor, and workmanship; require registration if needed.
Check References: Look for NATE- or manufacturer-certified installers and read recent reviews.

Lowest price is not always best value. A right-sized, well-installed furnace often costs less to own over time.

DIY And Safety Considerations

Gas appliances involve combustion, venting, and carbon monoxide risk. Many jurisdictions require licensed installers and permits for gas line and vent work.

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Do Not DIY Gas Piping Or Venting: Safety, code, and insurance implications are significant.
Install CO Detectors: Outside sleeping areas and on each floor per manufacturer guidelines.
Maintain Annually: Filter changes, blower cleaning, condensate checks, and combustion testing extend life.

Professional installation and annual service help ensure safety, efficiency, and warranty protection.

Quick Cost Calculator Examples

Scenario 1: Budget 80% Replacement

Home: 1,600 sq. ft., mixed climate, ducts in good shape.
Furnace: 70k BTU, 80% AFUE, single-stage.
Scope: Basic swap, new gas shutoff, reuse flue, no duct changes.
Estimated Cost: $4,100–$5,400.

Scenario 2: High-Efficiency Upgrade With New Venting

Home: 2,200 sq. ft., cold climate, existing metal flue not suitable.
Furnace: 90k BTU, 96% AFUE, two-stage ECM.
Scope: New PVC intake/exhaust, condensate pump and neutralizer, filter cabinet, permit.
Estimated Cost: $6,300–$9,200. Utility rebate may reduce net cost by $200–$600.

Scenario 3: Premium Modulating With Duct Improvements

Home: 3,000 sq. ft., Midwest, comfort complaints upstairs.
Furnace: 110k BTU, 97% AFUE, modulating variable-speed.
Scope: Return-air enlargement, new supply plenum, smart thermostat, commissioning.
Estimated Cost: $9,500–$13,500. Expect quieter operation and more even temperatures.

Frequently Asked Questions

How Long Does Furnace Installation Take?

Simple replacements are typically 6–10 hours. Add a day for new PVC venting, duct changes, or electrical work. Complex conversions can take multiple days.

How Long Does A Gas Furnace Last?

Typical life is 15–20 years. Heat exchanger condition, combustion quality, and regular maintenance drive longevity more than brand.

Is 80% AFUE Still Legal?

In many southern and mixed climates, yes. Some jurisdictions or utility programs favor 90%+ AFUE. Always check local code and incentive rules.

Do High-Efficiency Furnaces Need Special Drains?

Yes. Condensing furnaces produce acidic condensate that must drain to an approved receptor. A neutralizer may be required to protect plumbing; pumps are used where gravity isn’t possible.

Will My Existing Ducts Work?

Often, but not always. New furnaces may have different cabinet sizes and airflow needs. A duct pressure test helps identify restrictions that cause noise or reduce efficiency.

Should I Consider A Heat Pump Instead?

In moderate climates or where electricity is clean and affordable, a heat pump can lower emissions and operating costs. Dual-fuel systems pair a heat pump with a gas furnace for flexibility.

What Maintenance Is Required?

Change filters regularly, clean the blower and drain, and have a pro perform annual combustion and safety checks. This preserves efficiency and warranty coverage.

Can A Furnace Run Without Central AC?

Yes. A gas furnace can operate independently. If adding AC later, ensure the blower and coil space are compatible.

What To Look For In A Bid

A quality proposal should specify:

Model And AFUE: Exact furnace model, stage type, and blower motor.
Scope Of Work: Vent runs, condensate handling, gas/electric work, duct changes, and IAQ accessories.
Permits/Inspections: Included, with timeline and responsibilities.
Commissioning Tests: Static pressure, temperature rise, combustion analysis, CO checks.
Warranties: Parts, heat exchanger, and labor with any registration requirements.
Total Price And Payment Terms: Itemized materials and labor, with change-order policy.

Ask about load calculation results and how the proposed size was chosen. If calculations were not performed, request them.

Cost Breakdown Reference

Use this as a quick checklist while reviewing proposals.

Category	Typical Share Of Total	Notes
Furnace Equipment	35–55%	Varies with brand tier, size, and features.
Labor	25–45%	Higher for complex venting, tight spaces, or code work.
Venting/Condensate	5–15%	PVC runs, roof/wall caps, neutralizer, pump as needed.
Duct Modifications	0–20%	Can be minimal or substantial depending on airflow needs.
Permits/Inspection	1–5%	Local fees vary.
Accessories/Controls	2–10%	Thermostat, filter cabinet, IAQ devices.

Energy And Safety Resources

For standards, safety, and pricing data:

Key Takeaways

Typical Installed Cost: $4,000–$8,000 for standard replacements; $6,500–$12,000 for high-efficiency or complex jobs.
Biggest Cost Drivers: Furnace size, AFUE, features, venting, ductwork, and regional labor rates.
Savings: Moving from 80% to 96% AFUE can trim gas use by about 20%, with payback dependent on climate and gas price.
Get Better Bids: Demand Manual J, itemized scope, commissioning tests, and documented warranties.
Incentives: Utility rebates are common; federal credits for gas furnaces vary. Verify eligibility before buying.

How to Get the Best HVAC Prices

Firstly, keep in mind that installation quality is always the most important thing for residential HVAC project. So never sacrifice contractor quality for a lower price.
Secondly, remember to look up the latest rebates as we talked above.
Thirdly, ask for at least 3 bids before you make the decision. You can click here to get 3 free estimates from your local contractors, and this estimate already takes rebates and tax credit into consideration and filter unqualified contractors automatically.

Lastly, once you chose the right contractor, remember to use the tactics from this guide: Homeowners Tactics When Negotiating with HVAC Dealer to get the final best price.