Furnace replacement cost: prices by home size and fuel type

Furnace prices by home size

Angi says contractors size furnaces at roughly 30 to 60 BTUs per square foot and gives these 2026 installed ranges (Angi):

• 1,000 sq. ft.: $1,200 to $2,000
• 1,500 sq. ft.: $1,800 to $3,000
• 2,000 sq. ft.: $2,400 to $4,000
• 2,500 sq. ft.: $3,000 to $5,000
• 3,000 sq. ft.: $3,600 to $6,000

Prices by fuel type

• Natural gas: $3,800 to $10,000 (Angi).
• Electric: $2,000 to $7,000 (Angi).
• Oil: $6,750 to $10,000 (Angi).
• Propane: $3,700 to $14,200 (Angi).

Efficiency: pay more now, less every winter

Furnace efficiency is rated by AFUE; Angi calls 96% or more high-efficiency (Angi). ENERGY STAR says certified gas furnaces for northern states, including Illinois, are up to 18% more efficient than baseline models and can save about $160 a year in energy costs (ENERGY STAR).

Costs that can surprise you

Angi’s 2026 ranges for common extras (Angi):

• Permits: $400 to $1,500
• Removing the old unit: $60 to $330
• New ductwork, if needed: $2,000 to $5,000

Repair or replace?

ENERGY STAR says it may be time to replace if your furnace is more than 15 years old, needs frequent repairs or your energy bills are going up (ENERGY STAR). Angi says furnaces often last about 20 years and suggests replacing one older than 18 years that’s having problems (Angi). For smaller problems, start with our furnace repair guide.

Safety first

• Carbon monoxide. CPSC says to put CO alarms outside each sleeping area and on every level of the home (CPSC).
• Smell gas? Leave the house right away and call your gas company from outside. Nicor Gas customers can find emergency steps here.

How to pay less

• Get several quotes. Angi recommends comparing multiple contractors (Angi).
• Check rebates. Search the ENERGY STAR Rebate Finder for utility rebates. The federal home improvement credit only covered work through Dec. 31, 2025 (IRS).
• Keep it tuned up. ENERGY STAR suggests a heating check-up each fall (ENERGY STAR). Angi puts maintenance at about $60 to $550 a year (Angi).
• Struggling with the heat bill? See our Illinois heating bill help guide, including LIHEAP.

Would a home warranty help with the next furnace bill?

A home warranty is a service contract that helps pay to repair or replace some home systems and appliances. Know these numbers before you buy:

• Price. The DC Attorney General says a basic home warranty costs $500 a year or more (DC Attorney General). NerdWallet’s average was about $876 a year (NerdWallet).
• Service fee. You usually pay a fee for each repair visit, typically $75 or more (DC Attorney General). NerdWallet found an average of about $108 (NerdWallet).
• Is the item covered? Some plans exclude kitchen appliances, water heaters, furnaces and other major appliances, or charge extra to cover them (DC Attorney General).
• Caps and exclusions. Claims can be capped. Contracts can exclude wear and tear, manufacturer defects and problems from skipped maintenance. The company may repair rather than replace, and may pick the contractor (DC Attorney General).

Some plans cover furnaces in a base plan and others don’t, so check the cap for a full replacement. Don’t count on a brand-new plan to pay for something that’s already broken; read when coverage starts and what it excludes. See our home warranty cost guide.