Mountain View, CA

How much does a new gas furnace cost?

$2,000 – $5,200 Standard-efficiency unit replacement
$3,300 – $6,900 High-efficiency system installation

Gas furnace replacement costs $2,000 to $5,200 installed on average. Installing a natural gas furnace with new ductwork costs $4,400 to $11,800. New gas furnace prices are $800 to $2,700 on average for the unit, plus $900 to $3,000 for the install labor. Mobile home gas furnaces cost $900 to $2,500.

Get free estimates from furnace installers near you or view our cost guide below.

Reviewed and approved on June 15, 2021, by Tom Grupa and 12 expert furnace replacement companies on HomeGuide.

New gas furnace prices

A new gas furnace costs $2,000 to $5,200 on average to replace a standard unit. A high-efficiency gas furnace costs $3,300 to $6,900 installed on average. Operating a natural gas furnace costs $400 to $700 annually to run, or 30% to 85% cheaper than oil, electric, or propane furnaces.

Gas furnace cost to replace - chart
Gas furnace cost to replace - chart

Gas furnace prices
Home size (Square feet) Unit cost Total replacement cost
1,300 – 1,600 $600 – $2,200 $1,800 – $5,200
1,600 – 1,900 $650 – $2,400 $1,850 – $5,400
1,900 – 2,200 $700 – $2,500 $1,900 – $5,500
2,200 – 2,600 $800 – $2,700 $2,000 – $5,700
2,600 – 3,200 $900 – $2,800 $2,100 – $5,800

*Prices depend on the brand, size in BTUs, and efficiency.

  • Gas furnaces are the most common and last 15 to 25 years on average.
  • The best gas furnace brands are Payne, Rheem, Ruud, Trane, American Standard, and Bryant.
  • Compare furnace replacement costs of all fuel types, including gas, oil, and propane.

Average gas furnace prices

The following table shows the average price to replace a natural gas furnace.

Average gas furnace prices - chart
Average gas furnace prices - chart

Average gas furnace prices installed
National average cost $3,600
Minimum cost $1,800
Maximum cost $12,000
Average range $2,000 to $5,200

*Based on 419 project costs reported by HomeGuide members.

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Natural gas furnace cost

Natural gas furnace prices are $600 to $3,300 without installation, depending on the brand, size in BTUs, efficiency, and features.

New gas furnace prices by BTU

An average 66,000- to 80,000-BTU furnace costs $1,900 to $5,200 installed. Gas furnaces typically range from 40,000 to 140,000 BTUs. Contractors size the furnace based on the home’s square footage, insulation, climate zone, and heating needs.

Gas furnace cost by BTU
Furnace size (BTU) Average unit cost Total replacement cost
40,000 $600 – $1,700 $1,800 – $4,700
50,000 $650 – $1,800 $1,850 – $4,800
60,000 $700 – $1,900 $1,900 – $4,900
70,000 $800 – $2,000 $2,000 – $5,000
80,000 $900 – $2,200 $2,100 – $5,200
90,000 $1,000 – $2,400 $2,200 – $5,400
100,000 $1,100 – $2,500 $2,300 – $5,500
120,000 $1,200 – $2,700 $2,400 – $5,700
140,000 $1,300 – $2,800 $2,500 – $5,800

*Based on average prices for both standard and high-efficiency gas furnaces.

British Thermal Units (BTU) measures the amount of heat output. A 100,000 BTU furnace with 90% efficiency only produces 90,000 BTUs of heating.

Forced-air gas furnace price comparison by brand

A new forced-air gas furnace costs $800 to $2,700 on average, depending on the brand, size, and efficiency. Bryant or Lennox furnace prices are $800 to $7,500, while Goodman furnace prices are $600 to $3,200 on average.

The following chart shows the top gas furnace brands and prices, without installation labor:

Gas furnace brands and prices comparison
Brand Standard unit price High-efficiency unit price
AirQuest $650 – $1,700 $1,000 – $2,500
American Standard $850 – $2,600 $1,100 – $3,000
Blueridge $600 – $1,100 $900 – $2,000
Bryant $800 – $2,200 $2,000 – $3,400
Carrier $1,000 – $1,600 $1,400 – $2,800
Century $1,000 – $1,300 $1,300 – $1,500
Direct Comfort $600 – $1,500 $900 – $2,500
Goodman $600 – $2,000 $1,000 – $3,200
Lennox $1,400 – $3,000 $1,700 – $7,500
MRCOOL $800 – $1,100 $1,000 – $1,500
Rheem / Ruud $800 – $3,200 $1,300 – $3,900
Royalton $1,300 – $1,700 $1,900 – $3,200
Trane $1,200 – $1,900 $1,600 – $3,000
Winchester $1,200 – $1,500 $1,600 – $3,400
York $800 – $1,500 $1,200 – $2,000

*Installation labor adds $900 to $3,000 on average.

  • Gas furnace manufacturers' warranties are typically 5 to 12 years for the main components and 20 years for the heat exchanger. Many brands offer optional extended warranties.
  • Contractors often include a 1-year warranty on installation labor.
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Mobile home gas furnace prices

Mobile home gas furnace prices are $900 to $2,500 on average, depending on the brand and energy efficiency. Mobile home furnaces range from 80% to 95% in efficiency (AFUE). Downflow furnaces are the most common type since many mobile homes have ducts under the floors.

Mobile home gas furnace prices by brand
Brand Price range
Coleman $900 – $1,200
Miller $1,700 – $2,300
Revolv $1,000 – $2,500
Alpine $1,000 – $1,700

*Not including installation.

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High-efficiency furnace costs

A high-efficiency furnace costs $3,300 to $6,900 installed on average, depending on the brand, size, AFUE rating, and features. High-efficiency gas furnaces cost 30% to 50% more to install upfront but save $100 to $200 per year on operating costs.

High-efficiency furnace costs
Type AFUE Unit cost Total replacement cost
Standard efficiency 80% – 89% $600 – $1,900 $2,000 – $5,200
High-efficiency 90% – 99% $900 – $3,300 $3,300 – $6,900

A high-efficiency gas furnace is worth the cost for the extra benefits of:

  • Multiple fan speed options to save electricity costs
  • Variable heat settings such as two-stage or multi-speed blowers to lower natural gas bills
  • A secondary heat exchanger costs $1,000 to $2,000 to prevent heat loss through vents
  • Condensation-drain design for reducing emissions

AFUE rating

The Annual Fuel Utilization Efficiency (AFUE) rating measures the energy efficiency of furnaces. A higher AFUE percentage produces more heat on less fuel, lowering fuel costs. A furnace with an AFUE of 90 turns 90% of its fuel into usable heat.

  • High-efficiency furnaces have an AFUE in the 90's, while furnaces in the 80's are standard-efficiency.
  • Furnaces lose heat through air leaks, inefficient burners, exhaust, or a less-advanced design.
  • A high-efficiency unit may be eligible for an Energy Star federal tax credit of up to $300 and other local rebates.

Hybrid heating or dual-fuel systems that use an air-source heat pump and gas furnace are the most energy-efficient. Adding a heat pump costs $2,500 to $6,000 more on average.

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Cost factors to replace a gas furnace

The cost to replace a gas furnace depends on the unit’s efficiency and size in BTUs, ductwork modifications, labor, permits, and installation complexity.

Gas furnace installation cost
Service Average cost
Removal & disposal old furnace $150 – $400
Basic furnace install labor cost $900 – $3,000
Permits & fees $250 – $1,500
New duct installation $2,400 – $6,600
Duct replacement $1,400 – $5,600
Cleaning ducts $300 – $700
Insulation replacement $900 – $3,000
Zoning system $2,000 – $3,500
Home energy audit $200 – $500
Asbestos inspection / testing $250 – $700
Asbestos abatement $700 – $2,200
Chimney liner $900 – $3,800
Thermostat replacement $140 – $350
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Gas furnace ductwork cost

The cost to install a new gas furnace and ductwork is $4,400 to $11,800 on average. Replacing a gas furnace sometimes includes removing old ducts or cleaning existing ductwork for better airflow, especially in older homes.

  • Installing new ducts costs $2,400 to $6,600 on average.
  • The cost to replace ductwork is $1,400 to $5,600 on average or $25 to $55 per linear foot.
  • Duct cleaning costs $300 to $700 on average or $25 to $45 per vent to keep the system running efficiently and maintain good air quality.
  • Duct repair costs $200 to $700 on average, depending on the duct type, location, and size.
  • Ductwork sealing costs $400 to $2,700 to fix vent leaks.
  • Asbestos inspection and testing costs $250 to $700 and is important for homes built before or during the 1970s.
  • Asbestos abatement costs $400 to $2,700 when replacing ductwork.
  • A home energy audit costs $200 to $500 to check for leaks and efficiency optimizations.

Gas furnace labor installation cost

Gas furnace installation labor costs $900 to $2,200 alone for standard-efficiency models or $1,200 to $3,000 for high-efficiency systems. Gas furnace installations take 4 to 10 hours on average. High-efficiency units take longer due to the complexity and additional vents required.

Furnace services cost $75 to $150 per hour on average, not including parts.

Gas furnace labor installation cost
Type Average cost
Standard efficiency $900 – $2,200
High-efficiency $1,200 – $3,000

HVAC contractor installing a new gas furnace
HVAC contractor installing a new gas furnace

  • An HVAC contractor charges $70 to $100 per hour, plus $30 to $50 per hour for an assistant.
  • Electrical work costs $100 to $250 minimum on gas-furnace control connections.
  • Most contractors include gas and carbon monoxide testing in their installation labor price.
  • Installing new insulation costs $900 to $3,000 on average.
  • Installing a chimney liner costs $900 to $3,800 and prevents masonry damage from the moisture in the natural gas exhaust.
  • Thermostat replacement costs $140 to $350 on average.
  • An HVAC zoning system costs $1,700 to $4,500 to install. Zoned houses have 30% lower energy bills through controlled heating and cooling of each room.

Removing a gas furnace cost

Removing and disposing of an old gas furnace costs $150 to $400 on average, depending on the size, location, and local disposal fees. Extra fees apply when removing from areas with limited access. Most contractors include this service in their estimate.

Upflow vs. downflow gas furnace

The difference between an upflow and downflow furnace is the position of the hot-air supply vent, which depends on the home ductwork layout. Most upflow and downflow gas furnace units cost the same price. Downflow units are the best gas furnace for attics, but basements need upflow units.

Upflow vs. downflow gas furnace
Upflow Downflow
  • More efficient and better heating comfort
  • Ideal for cool and cold climates
  • Installed in crawl space, basement garage, or first floor of a slab home
  • Less efficient
  • Better for warm climates
  • Installed in an attic or upper stories
  • Often used in mobile homes
Newer multi-positional units offer the flexibility of horizontal, downflow, or upflow installation options.

Permits and inspection fees

Gas furnace permits and inspections cost $250 to $1,500 on average, depending on the location and whether it’s a replacement or new installation. All types of gas furnace replacements, installations, and gas line repairs require permits. Contractors typically pull all permits.

Additional permits may apply:

  • Electrical permits cost $50 to $350+ when upgrading electrical connections.
  • Gas line permits cost an extra $50 to $200. Lower fees are for connecting to existing gas lines, and higher fees apply for installing new gas lines.

Gas furnace conversion costs

  • The cost to convert a propane furnace to natural gas is $650 to $1,500 to install a conversion kit, remove the propane tank, and install a gas line.
  • Converting an oil furnace to gas costs $2,200 to $8,800 and requires replacing the furnace, removing the oil tank, and installing natural gas lines.
  • Converting an electric furnace to gas costs $1,800 to $5,300 and includes replacing the furnace and installing natural gas lines.

Cost to convert to gas furnace - chart
Cost to convert to gas furnace - chart

Cost to convert to natural gas furnace
Conversion type Average cost Typical work involved
Oil to gas $2,200 – $8,800
  • Replacing the furnace
  • Removing the heating-oil tank
  • Installing or connecting natural gas lines
Electric to gas $1,800 – $5,300
  • Replacing the furnace
  • Installing or connecting natural gas lines
Propane to gas $650 – $1,500
  • Uses the existing furnace
  • Installing a conversion kit
  • Removing the propane tank
  • Installing or connecting natural gas lines
Gas to propane
(buying tank)
$1,900 – $4,900
  • Uses the existing furnace
  • Installing a conversion kit
  • Installing a propane tank & lines
Gas to propane
(leasing tank)
$275 – $800
  • Uses the existing furnace
  • +$50 to $200 annual tank rental fee
  • Installing a conversion kit
  • Free or discounted tank install labor
  • Installing tank line connections

*Prices don’t include new gas line installations and piping extensions.

Additional costs may include:

  • A new gas line installation costs $500 to $2,000 on average or $12 to $25 per linear foot.
  • Furnace conversions sometimes require new ductwork. Ductwork replacements cost $1,400 to $5,600 on average.
  • Removing an oil tank costs $1,000 to $3,500 for an underground or $400 to $1,500 for an above-ground. Oil tank removal is mandatory in most states for safety reasons.
  • Switching to natural gas may require a chimney lining to prevent masonry damage. A new chimney liner costs $900 to $3,800 installed.
Alternatively, replacing an existing oil furnace costs $2,500 to $6,000, and replacing an electric furnace costs $1,900 to $5,600.

Propane gas furnace

Propane furnace costs are equal to natural gas, and both use the same furnace. Converting a gas furnace to propane costs $150 to $500 to install a conversion kit, plus $50 to $200 annually for renting a propane tank.

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Operating cost to run a gas furnace

Operating a gas furnace costs $400 to $700 per year in energy costs to run on average. Natural gas heating is 30% to 85% cheaper than oil, electric, or propane furnaces. Operating costs depend on the home’s size, climate, local fuel prices, and the furnace’s energy efficiency.

Operating cost to run a furnace - chart
Operating cost to run a furnace - chart

Gas furnace operating cost calculator
Fuel type Annual cost to run
Natural gas $400 – $700
Propane $1,000 – $2,500
Oil $1,000 – $1,750
Electric $1,600 – $2,200
High-efficiency gas furnaces with variable-speed blowers and motors cost $100 to $200 less annually to run.

Are propane furnaces more efficient than natural gas?

Propane furnaces are more efficient and use 2.0 to 2.5 times less fuel to heat a home than natural gas heating. Although propane has a higher BTU heating-efficiency rating, propane costs 2 to 3 times more to operate than natural gas.

A high-efficiency propane furnace with variable-speed blowers and multiple-heating stages uses the least energy.

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What size gas furnace do I need?

The most cost-effective gas furnace size needs 20 to 60 BTUs per square foot, depending on the climate zone. An average 1,600- to 2,600-square-foot home needs a 40,000- to 130,000-BTU gas furnace. The home’s size, climate, and level of insulation determine the furnace size needed.

Gas furnace size calculator
Home size (square feet) BTU output needed
1,200 – 1,600 30,000 – 80,000
1,600 – 1,900 40,000 – 95,000
1,900 – 2,200 45,000 – 110,000
2,200 – 2,600 55,000 – 130,000
2,600 – 2,800 65,000 – 140,000

*Based on the average 25 to 50 BTUs per square foot.

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Furnace size calculator - heating climate zones
Furnace size calculator - heating climate zones

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Frequently asked questions

How much does a 3-ton gas furnace cost?

A 3-ton (36,000 BTU) gas furnace costs $600 to $1,700 without installation, depending on the brand and efficiency. Suppliers typically use the “ton” metric for comparing AC unit cooling capacities. Furnace sizes are measured using BTUs. One ton is equal to 12,000 BTUs.

What is the best gas furnace to buy?

The best gas furnace brands to buy are Payne, Rheem, Ruud, Trane, American Standard, and Bryant, according to consumer ratings. Furnaces with “variable-speed” blower motors and “modulating” gas valves have a wider range of heat settings for precise temperature control.

What is a cheap gas furnace price?

A cheap gas furnace for a house costs $600 to $1,000 on average for standard 80% efficiency models from brands like Goodman, Direct Comfort, and Blueridge. Cheap gas furnaces have single-stage or multi-speed motors and valves, which allow only 1 to 2 heat settings.

How long does a gas furnace last?

A gas furnace lasts 15 to 25 years on average. The lifespan depends on the brand, quality, usage, location, and maintenance frequency. A properly sized gas furnace system with annual maintenance lasts the longest.

Warning signs to replace a gas furnace:

  • Persistent gas odors around the furnace
  • Yellow pilot light instead of blue
  • Loud, unusual furnace noises
  • Only cool air from vents
  • Cracks and rust on the furnace housing
  • Drastically higher monthly gas bills

Does a gas furnace use electricity?

A gas furnace needs electricity to run the fan motor, igniter, circuit boards, and relays.

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Hiring a gas furnace installer

Hiring an experienced furnace installer is essential for safety and quality. Homeowners cannot legally install gas furnaces on their own due to the fire hazards and risks of carbon monoxide poisoning from faulty installations.

When selecting a furnace contractor:

  • Verify the contractor and their crew all have licenses, insurance, and bond guarantees.
  • Choose HVAC installers with credentials from a North American Technician Excellence (NATE) organization like the American Society of Heating, Refrigeration, and Air-Conditioning Engineers (ASHRAE).
  • Look for furnace technicians with 2 to 5 years of experience minimum.
  • Compare bids from at least three contractors.
  • Request copies of itemized estimates, heating-load calculations, billed orders, permits, warranties, and contracts.
  • Beware of the lowest estimates that often mean lower-quality installations.
  • Compare their reviews on HomeGuide, the Better Business Bureau (BBB), and Google.
  • Understand the total project cost before signing contracts.
  • Avoid paying in full upfront. Make a payment schedule for work completed to avoid scams.

Questions to ask

  • Which gas furnace brands do you install?
  • How many gas furnace installations have you done?
  • Can I see a list of references from your past projects?
  • Does this furnace qualify for local tax credits or rebates?
  • Will you manage an electrician for the furnace hookups to thermostats?
  • What types of furnace repairs does your warranty cover?
  • Will you size the new gas furnace using a Manual J load calculation?
  • How much will permits and inspections cost?
  • Does your estimate include all labor, materials, cleanup, and equipment fees?
  • Does your estimate include disposing of the old furnace?
  • Do I need ductwork modifications to connect to the new furnace?
  • Will you check for issues with electrical connections, ductwork, or gas lines before the installation?
  • Does my ductwork need extra sealing?
  • Will you test my air quality after installation for carbon monoxide leaks?
  • Do you offer an ongoing service plan for this furnace?
  • How long will the installation take?
  • Does my contract guarantee the exact make, model number, and energy rating of my new gas furnace?
  • What types of financing plans do you offer?

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