How Much Does Gas Furnace Replacement Cost?

Common Range: $3,685 to $7,230 Installed

National Average: $5,660 Installed

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Get Free Gas Furnace Cost Quotes
Updated: January 2, 2023, by: Steve Hansen

New Furnace Installation Cost

The cost to have an LP or natural gas furnace installed or replaced is around $3,980 for a standard efficiency furnace in a 1500 sf home. A high performance, high efficiency gas furnace installed by an HVAC Pro in the same home costs an average of $7,230 when only the gas furnace is replaced. If you need AC at the same time, expect the cost to go up.

When you have a local HVAC licensed company handle your installation it will generally include the following. The new gas furnace and all installation supplies to complete the job. All labor costs for 2 or more HVAC technicians to complete the install. Removal and disposal of the old furnace when applicable. Modification of the existing transition, or a new transition duct to fit the new furnace and connect it to your duct work. Complete cleanup of the work area and the path the workers used to go back and forth to their vehicles. All required permits and inspections of the job when it’s completed.

Average Replacement Cost

Standard Efficiency Furnace (80% AFUE)
$3,980 Installed
Mid-Efficiency Furnace (90% AFUE)
$5,660 Installed
High Efficiency Furnace (93%+ AFUE)
$7,230 Installed

high efficiency furnace installed in utility room

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Overview of Gas Furnace Replacement

In many forced hot air HVAC systems, a gas furnace provides both heating through the furnace itself and also the air handler for the air conditioning system in your home. Replacement cost will vary greatly depending on many factors specific to your home, the rest of your heating and air system, and the type of new gas furnace you choose to install.

This Cost estimate page will help you learn more about options you have where furnace replacement is concerned. We’ll explain the cost variables within your home itself that will affect furnace pricing, as well as why it might be more beneficial to replace the entire system at the same time. You’ll learn about new furnace features and technology that can increase the initial cost at time of installation, but reduce operating costs over the life of the furnace. We’ll also share our thoughts on DIY furnace replacement as well as cost comparisons from around the web and from homeowners like yourself, who have recently replaced their own gas furnace or system.

Gas Furnace Cost Factors

As for the furnace cost itself there are several features and factors that will determine the wholesale price of your unit. Only you can decide which of these features is important for your needs, but some features will also have an effect on the installed furnace price, due to additional requirements or modifications to the rest of your HVAC system at time of install.

  • Furnace Size or Heating Capacity (BTU’s) – Furnaces are available from 40,000 to 160,000 btu’s. Larger capacity furnaces cost more and heat a larger number of square feet. The size you need will be determined by the size in square feet, and heat loss associated with your home.
  • Number of Heating Stages – Single, 2 or even 3 stage gas furnaces are available. This is an efficiency and comfort feature. Single stage furnaces burn at a single, constant flame size (ex: 60,000 btu). Multi-stage furnaces have a gas valve that feeds more or less gas to the burner, resulting in 2 or 3 stages of heating (ex: 40k, or 60k, or 80k btu, depending on demand). Single stage furnaces are the most affordable and lowest efficiency, and multi-stage burners cost more, and result in higher efficiency and lower operating costs.
  • Type of Blower Motor – There are several types of blowers available for gas furnaces.  The most common are fixed speed blowers (uses 1 blower volume), multi-speed blowers (Like a hair drier, with 2-3 defined speeds), and modulating speed blowers (any speed between 400-2000 cfm). Fixed speed units cost less but use more energy to run, and modulating blowers cost the most, but have the highest efficiency and comfort.
  • Fuel Efficiency (AFUE) – Available between 80% – 98% AFUE (Fuel Utilization Rating), lower efficiency units are less costly to install but you spend more money to operate. High efficiency furnaces are more expensive at the time of purchase, but cost considerably less over the life of the unit.
  • Brand Name and Quality Rating – Different brands of furnaces cost more than others. This can be due to manufacturing differences, factory location and cost of labor, brand ratings, and dealer partnerships. Lower cost furnaces are available to buy on the web as a consumer and install yourself or hire a pro. Higher priced furnaces are only available through the brands dealer network, and must be installed by an authorized dealer.
  • Built-in Technology or Communications – Some furnaces are simple “On or Off” units. When the thermostat calls for heat, they turn on and run until the demand is met, and shut off. Newer, communicating gas furnaces interface with smart controllers to automatically adjust to different needs in your home and communicate with smart phones, thermostats, etc.
  • Difficulty or Ease of Installation – The location of your furnace in the home is going to play a slight role in the furnace cost. If your furnace is located in a 24″ high crawl space foundation for example, it may cost more than a home where the gas furnace is located in a first floor utility room. This is largely due to the added time and difficulties involved with limited space and ease of access for the installers.
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Gas Furnace and Installation Supplies Cost

As we mentioned, there are many factors that will determine your total cost for a new replacement gas furnace. The prices listed below represent the dealer or wholesale cost of the furnace only, before any labor, installation, or accessory costs are added.

Furnace Only Costs

  • $650 – $1,250 – 40k-120k btu 80% AFUE, single stage burner, fixed speed blowers. Very little smart technology. Low end of brand ratings.
  • $1,375 – $2,850 – 40k-160k btu 90-95% AFUE, single/multi stage burners, single or multi-speed blowers. Smart technology. High end of brand ratings.
  • $3,150 – $3,900 – 40k-160k btu 95-98% AFUE, multi stage burners, variable-speed blowers. Many smart features and communicating features. High end of brand ratings.

Furnace Installation Supplies

Regardless of whether this is brand new or a replacement gas furnace or you’re just researching furnace prices, there may be supplies needed during the installation. Most reputable contractors will replace all of this, included in their quote.

  • $25 – $60 | Sheet metal for transition / plenum to return and supply air duct.
  • $60 – $760 | New Thermostat.
  • $95 – $290 | Concentric kit, PVC pipe, or B-Vent for furnace flue and fresh combustion air.
  • $45 – $1.55 | Condensate pump or drain line supplies for 90% or higher AFUE furnaces.
  • $25 – $150 | Gas line supplies for connecting existing gas line to new furnace.
  • $35 – $125 | Electrical wire, and/or new circuit breaker for connecting to power.
  • $35 – $100 | Miscellaneous screws, fasteners, mastic, tape etc.

Permits, Inspection, and Furnace Installation Costs

A new gas furnace installation usually requires a permit and inspection. In some cases, a Manual-J load report will need to be completed before a permit is issued. A contractor is required in most states to have the unit inspected in order to complete the job and assure the safety and thoroughness of the project. In some states, DIY’ers can do the install themselves at their own home but an inspection is still required.

Permit and/or Inspection

  • $50 – $200 ea. | Local permits (if required). You will likely require electrical, mechanical and plumbing inspections.

Furnace Installation Labor Cost Factors

Variables within your home and with the contractor can have an effect on the overall installation cost of a gas furnace.

  • Furnace Location – The harder it is to get to your furnace and heating system, the more it’s going to cost to replace. For example, if you have a utility closet on the first floor of your home, the contractor has very easy access to the unit. However, if it’s located in the back corner of your attic and the only way in or out is through a small attic-door, it’s going to be more time consuming and costly.
  • Age and Condition of Old System and Ductwork – Newer systems are much more efficient than 15 years ago. If a contractor (or you) need to upgrade duct, gas lines, electrical, or any other number of things associated with a new furnace, they may required to bring the rest up to current code. This can get costly, quickly.
  • Supply and Demand of Contractor – If the weather hits 20 degrees and contractors are very busy with installs in your area, they can and will increase their pricing based on demand. Alternatively, if you replace your furnace when business is slow, they’ll do it for much cheaper just to keep their crews working.

Installation Time

  • 1 Day | A simple and uncomplicated upfit furnace installation in an easy to access location of your home is generally completed within 1 day. It may take a second day for inspections.
  • 2 Days | If your system requires new flue vents, new electrical, new plumbing of a gas line, or new duct to be run in order to meet the new efficiency, expect longer installation time.
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Are You an HVAC or Gas Furnace Installer?

If so, head over to our Costimates Pro’s page, and help us make this page better and more accurate for both our visitors and your future customers.

DIY or Hire a Pro?

While you might be tempted to install your own furnace, if you aren’t on the upper end of the handyman scale, this is not an advisable practice. Even if you are a skilled handyman, it’s smart to hire a helper who works with HVAC, in order to make sure its done properly and will pass a safety inspection. Furnace replacement is one of the 10 most expensive repairs for your home, it only makes sense to let a Pro do the job.

Note: Many furnace manufacturers require an approved permit and inspection, as well as start-up from an licensed contractor to honor the warranty of the product. You could buy the best furnace on the market, and get very poor performance from it if it’s not installed correctly.

I worked with an HVAC company in the past. With the help from 2 installers on a day off, we installed a new gas furnace at my home and had it inspected the following week as a homeowner installed appliance. I would not have attempted this on my own otherwise. It’s a big project and safety is the most important factor. My situation was unique in that I had skilled labor and connections in the industry to get it done right. I would not do it again without that help, therefore, I always suggest a pro when it comes to a new furnace or HVAC system.

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Reviewed and Edited by Steve Hansen of Costimates

steve hansen of costimates-sm Steve Hansen is the Lead Editor of Costimates. (Learn more) An avid home improvement professional with more than 35 years experience in both DIY projects and working as a construction foreman in residential new home building, upfits, repairs and remodeling.

"Like most homeowners, I became frustrated with the lack of quality information available on specific home improvement repairs and renovations. In 2015, Costimates was formed to help homeowners learn as much as possible about various projects and their costs so they could make better financial decisions."