Furnace quotes are notoriously hard to compare because two contractors can bid the same house at $5,200 and $11,400 and both be quoting honest work — they are just quoting different equipment, different efficiency tiers, and different amounts of sheet metal. This guide breaks down 2026 furnace replacement pricing by fuel type and efficiency, explains which install variables legitimately move the number, and shows you exactly which line items to compare so three bids become an apples-to-apples decision instead of a guessing game.
A straightforward gas furnace replacement in an average 1,800 to 2,400 square foot home runs $4,500 to $8,500 installed. The low end is an 80 percent AFUE single-stage unit in an easy basement swap; the high end is a 96 percent AFUE two-stage or modulating unit with a variable-speed ECM blower, new venting, and a condensate pump. Premium modulating systems with zoning push past $12,000.
Electric furnaces are cheaper to install at $2,500 to $5,000 but far more expensive to run in most climates. Oil furnaces run $6,000 to $11,000 installed. Propane costs about the same as natural gas to install but 40 to 90 percent more to operate depending on regional propane pricing. Equipment alone is typically 45 to 55 percent of the total; the rest is labor, materials, permits, and disposal.
The upgrade from an 80 percent to a 96 percent unit typically costs $1,500 to $2,500 more, partly for the equipment and partly because a condensing furnace needs PVC venting through a sidewall and a condensate drain rather than reusing the existing chimney flue. In a cold climate burning 800 to 1,200 therms a season, that upgrade saves roughly $180 to $350 a year and pays back in six to nine years — comfortably within the unit's life.
In a mild climate where the furnace runs a few hundred hours a season, the payback stretches past fifteen years and an 80 percent unit is the rational choice. One complication worth knowing: if you remove an 80 percent furnace from a chimney shared with a gas water heater, the flue may become oversized for the water heater alone and need relining, which is a legitimate $600 to $1,800 line item, not an upsell.
Sizing and location come first. A tight crawlspace or attic install costs more in labor than a basement. Converting from an upflow to a horizontal configuration, moving the unit, or building new plenum and transition ductwork adds $500 to $2,000 in sheet metal work. Permits and inspection run $75 to $400 depending on the jurisdiction and are not optional — an unpermitted install can complicate a future home sale.
Other real adders include a new thermostat ($150 to $500 for a smart model installed and configured), a dedicated electrical circuit or a new disconnect ($200 to $600), chimney liner work, asbestos-wrapped old duct abatement, and a combustion air intake for a tightly sealed home. What should be included in any honest quote: removal and disposal of the old unit, a new filter cabinet, gas line connection, startup and combustion analysis, and manufacturer warranty registration.
The single biggest determinant of how a new furnace performs is whether it is sized correctly, and the industry's chronic problem is oversizing. An oversized furnace satisfies the thermostat quickly, short-cycles, leaves the house with hot and cold spots, and wears its ignition components out faster. The correct method is a Manual J load calculation based on your square footage, insulation levels, window area, orientation, and local design temperature.
Ask every bidder whether they performed a Manual J and ask to see it. A contractor who sizes by replacing whatever BTU rating is currently installed is copying a decision someone else may have made badly thirty years ago. Typical correctly sized residential furnaces land between 40,000 and 100,000 BTU. When in doubt, the properly sized unit will run longer cycles at lower output — that is what good comfort feels like.
Ask each contractor for the same information in writing: exact model number, AFUE, stage count, blower type, BTU output, warranty terms on both parts and labor, whether a Manual J was run, what ductwork or venting is included, permit handling, and total price with tax. With model numbers in hand you can compare equipment directly and see whether the $3,000 spread is better hardware or better margin.
Also check rebates before signing. Utility rebates on high-efficiency gas furnaces commonly run $200 to $800, and many states layer additional incentives on top, particularly for ECM variable-speed blowers. Federal efficiency tax credits have applied to qualifying 97 percent AFUE units in recent years — confirm current-year eligibility with your installer or tax preparer, since the rules change. A good contractor files the utility rebate paperwork for you.
Most homeowners pay $4,500 to $8,500 for a gas furnace replacement in an average-sized home. An 80 percent AFUE single-stage unit sits at the low end, and a 96 percent two-stage with a variable-speed blower at the high end. Electric furnaces install for $2,500 to $5,000, and pairing a furnace and AC replacement together typically runs $9,000 to $16,000.
A well-maintained gas furnace lasts 15 to 20 years, and electric furnaces often reach 20 to 30 because they have no combustion components. Annual maintenance, regular filter changes, and correct sizing are the three factors that matter most. Once a unit passes 15 years, weigh any repair over about $1,500 against replacement rather than automatically fixing it.
If the AC is within a few years of the furnace in age, usually yes. The two share the blower and cabinet, labor overlaps substantially, and doing both saves roughly $1,000 to $2,000 versus two separate projects. It also guarantees the coil and blower are properly matched, which affects both efficiency ratings and warranty coverage.
That requires a Manual J load calculation, not a rule of thumb. It accounts for square footage, insulation, window area and orientation, air sealing, and your local design temperature. Most correctly sized residential furnaces fall between 40,000 and 100,000 BTU. Insist on seeing the calculation — oversizing is the most common installation error and it causes short cycling and uneven temperatures.
Frequently. Utility rebates on high-efficiency gas furnaces commonly run $200 to $800, with additional state incentives in many regions, especially for variable-speed ECM blowers. Federal energy efficiency tax credits have applied to qualifying high-AFUE equipment in recent years but the rules change annually, so confirm current eligibility with your installer or tax preparer before signing.
In a cold climate with long heating seasons, generally yes. Two-stage units run at about 65 percent output most of the time, which means longer, gentler cycles, more even temperatures, quieter operation, and better humidity control. The premium is usually $700 to $1,500. In a mild climate where the furnace runs a few hundred hours a year, a single-stage unit is the better value.