How Much Does It Cost to Replace a Gravity Furnace? [2026 Data]

In 2026, the national average cost to replace a gravity furnace is $6,300. Most homeowners pay between $4,500 and $11,000, depending on the furnace type, ductwork modifications, and whether asbestos removal is needed in older homes.

Gravity Furnace Replacement Cost Factors: What Affects the Price?

Replacing a gravity furnace typically costs $3,000 to $15,000, with the removal of the old unit alone requiring many hours of labor on top of the price of the new equipment. If there are any signs of asbestos in the furnace or ductwork, both your costs and the scope of work will increase significantly.

Labor

Furnace labor runs $75 to $100 per hour for a straightforward replacement, and the job typically takes 6 to 12 hours from start to finish. If asbestos is present, costs climb further because asbestos requires professional removal, and some contractors will not take on large ductwork jobs alongside the furnace swap. Costs vary depending on the total hours worked, as shown in the breakdown below.

Prep

At least half of your total labor cost goes toward removing the old gravity furnace, so thorough prep work is essential before the new unit can go in. Inspecting all the ductwork costs $230 on average and is a key part of that preparation, helping confirm what can be reused and what needs to go.

- Ensuring there is a safe and clear pathway to remove the old furnace.

- Arranging for pickup or finding a metal scrap facility, if you're DIY the removal.

- Ensuring your new furnace is up to code. A pro can do this for you.

- Shutting off all utilities.

- Disconnecting the old furnace.

Once you've completed the prep work, you need to ensure you have all the tools to perform the removal. Removing an old furnace usually requires a screwdriver, crowbar, dolly, and some friends to help with the heavy lifting. You may also need a metal saw.

Types of Replacement Furnaces

Once the gravity furnace is removed, it's time to swap it for a different heater. Each type of furnace has its advantages and disadvantages, which one you choose will come down to your budget, available hookups, and preference. Here are the replacement furnace types and their average costs:

Natural Gas

A natural gas furnace is the most common replacement choice in modern homes, with costs ranging from $3,800 to $10,000, and its efficiency means shorter run times and lower electricity bills compared to other fuel types. The fuel itself is inexpensive, so the higher upfront investment often pays off over the life of the unit.

Electric

An electric furnace, priced from $2,000 to $7,000, is a practical option for homes where natural gas is unavailable or where winters are mild enough that a less robust heating system will do. It costs less to purchase and install than a gas unit and requires very little maintenance, but it heats slowly and typically results in a higher monthly electric bill.

Oil

An oil furnace, which runs $6,750 to $10,000, sits between natural gas and electric in terms of efficiency and is generally considered safer than a gas unit. It requires more maintenance, fuel costs can be high, and it produces carbon monoxide, making it a less environmentally friendly choice than the alternatives.

Propane

A propane furnace costs $3,700 to $14,200 to install, making it one of the pricier options, and it is less efficient than natural gas. That said, some homes can run an entire winter on a single large tank, keeping the seasonal heating bill to around $800.

Unique Cost Factors When Replacing or Converting a Gravity Furnace

Gravity furnaces are an outdated technology. Like other older appliances, there are certain quirks that need to get ironed out, even when removing such equipment, to bring it up to a modern standard. Depending on when it was installed, you might want to consider the presence of asbestos. This naturally occurring mineral can be quite dangerous when handled incorrectly.

Ductwork Modification

Ductwork modification is often the most extensive and costly part of a gravity furnace replacement, particularly when asbestos is present and a full system removal is required. If the ducts are asbestos-free and only need to be brought up to code, the work is far less involved, though installing new ductwork still runs $2,000 to $5,000.

Asbestos Removal

Asbestos is a known carcinogen no longer used in new construction, but it remains a real concern in older homes with gravity furnaces, which is why hiring a pro to inspect for asbestos before any work begins is strongly recommended. While asbestos may be confined to the furnace itself, it is more commonly found throughout the entire duct system, which would require a complete removal rather than a targeted fix.

DIY Replacing a Gravity Furnace vs. Hiring a Pro

If it were a modern furnace, you could remove and replace it yourself. It would require some strength and time, but it's a doable job. The issue with a gravity furnace is that because they're old tech, they often weigh a literal ton and may contain materials that can be hazardous to your health, and to the health of your household.

For these reasons, we strongly recommend hiring a professional to remove and replace the unit and, if necessary, the ductwork. If the unit (and the ductwork) is free of dangerous chemicals, you may be permitted to work alongside the professional. If there is asbestos, or if you are unsure if it's present, you need to hire a local asbestos removal professional for safety reasons.

Ways to Save Money While Replacing a Gravity Furnace

There are really only a few ways you can save money when replacing a gravity furnace. The choice is usually out of your control, as it will be dictated by the condition of the existing furnace (and ductwork), and the available heating methods in place for your home.

If you do have the option of the type of furnace you install, some money-saving tips include:

• Installing the furnace type that will save you the most money over time, as furnaces seldom need replacing.

• Discussing fuel options with multiple providers.

• Repurposing and reusing the existing ductwork, if there is no asbestos.

• Purchasing a used furnace, especially if you go electric.

• Installing in late spring or summer when contractors are in lower demand.

• Selling your old furnace (for scrap metal).

How Angi Gets Its Cost Data

Home is the most important place on earth, which is why Angi has helped more than 150 million homeowners transform their houses into homes they adore. To help homeowners with their next project, Angi provides readers with the most accurate cost data and upholds strict editorial standards. We extensively research project costs to develop the pricing data you see, so you can make the best decisions for you and your home. We rely on reputable sources, including the U.S. Bureau of Labor Statistics, academic journals, market studies, and interviews with industry experts—all to ensure our prices reflect real-world projects. 

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