How Much Does It Cost to Replace a Gravity Furnace?

On February 25, 2026 By newsroom Topic: Home Services

Replacing a gravity furnace can be complex and costly due to the size, weight, and potential asbestos presence. Here's a breakdown of key cost factors:

1. Cost Breakdown

| Component | Average Cost | |------------------------------|----------------------------| | Labor (6–12 hours) | $450–$1,200 | | Ductwork modification | $2,000–$5,000 | | Asbestos removal | $1,200–$3,000+ | | New furnace (unit + install) | $2,000–$14,200 (type-specific)|

Total Cost

Expect to pay $5,000–$20,000+, depending on the furnace type, ductwork, and asbestos issues.

2. Furnace Replacement Options

| Furnace Type | Cost (Unit + Install) | Advantages | Disadvantages | |-----------------------|--------------------------|------------------------------------------|------------------------------------------| | Natural Gas | $3,800–$10,000 | Efficient, lower operating costs | Higher upfront costs | | Electric | $2,000–$7,000 | Low maintenance, cheaper installation | High electricity bills in cold climates | | Oil | $6,750–$10,000 | Safer than gas, efficient heating | Expensive fuel, higher maintenance | | Propane | $3,700–$14,200 | Long-lasting fuel, flexible placement | High initial costs, less efficient |

3. Factors Impacting Cost

Labor

Hourly Rate: $75–$100/hour.
Time Needed: 6–12 hours for basic jobs; more with asbestos or ductwork issues.

Ductwork Modifications

If ducts contain asbestos, complete removal/replacement may be required.
Cost: $2,000–$5,000 for new duct installation.

Asbestos Removal

Cost: $1,200–$3,000+ (varies based on the extent of contamination).
Hire licensed asbestos abatement professionals for safety.

4. DIY vs. Hiring a Professional

DIY Pros: Cost savings on labor.
DIY Cons:
Gravity furnaces are extremely heavy (often over a ton).
Potential asbestos hazards require professional handling.
Improper installation can lead to inefficiency or safety risks.

Recommendation: Always hire a professional, especially if asbestos is present or the furnace is old and unwieldy.

5. Money-Saving Tips

Reuse Ductwork: Only if it’s asbestos-free and in good condition.
Shop Off-Season: Install in spring or summer for potential discounts.
Buy Used Units: Especially for electric furnaces in moderate climates.
Sell the Old Furnace for Scrap: Offset removal costs.
Choose Energy-Efficient Systems: Reduce long-term utility bills.

6. Key Considerations

Safety First: Test for asbestos before starting the project.
Efficiency: Opt for modern systems to lower long-term heating costs.
Professional Help: Ensure proper removal, installation, and compliance with local codes.

Replacing a gravity furnace is an investment in efficiency and safety, with significant upfront costs but potential savings over time.