Furnace replacement costs $3,000 to $7,500 for a typical US home in 2026, with most gas furnace installs landing around $4,500 to $6,000. A basic 80% AFUE unit in an easy install can come in near $3,000, while a high-efficiency modulating furnace with new venting can pass $10,000. Where your job lands depends mostly on the furnace’s BTU size, its AFUE efficiency, the fuel type, and how much the install touches your venting, ductwork, and electrical.
A furnace is one of the larger single HVAC purchases a homeowner makes, and it is easy to overpay or undersize. Knowing what actually drives the number lets you read a quote critically, compare bids on equal footing, and decide whether this is a repair year or a replacement year before a contractor ever walks the basement.
Furnace Replacement Cost at a Glance
The fastest way to ballpark a job is by efficiency tier, then sanity-check it against your home’s size and fuel type.
| Efficiency / type | Typical installed price | Notes |
|---|---|---|
| 80% AFUE, standard gas | $3,000 – $5,500 | Single-stage, metal flue vent; lowest up-front cost |
| 90 – 96% AFUE, condensing gas | $4,500 – $7,500 | PVC intake/exhaust + condensate drain; lower fuel bills |
| Modulating high-efficiency (97 – 98%) | $6,000 – $10,000+ | Variable-speed blower, quietest, best comfort & efficiency |
| Electric furnace | $2,500 – $6,000 | No combustion venting; running cost depends on electric rates |
| Oil furnace | $5,500 – $10,000 | Oil tank, filtration, and chimney work add to the total |
These are installed figures including labor, framed as typical 2026 US ranges — not quotes. The single biggest lever inside each row is the furnace size in BTU, which should come from a proper load calculation rather than a guess. Our Furnace BTU Calculator gives you that number, and the Furnace Sizing Guide walks through why oversizing is the most common and most expensive mistake.
Installed furnace cost by efficiency
What Drives Furnace Cost Up or Down
Two homes the same size can quote thousands of dollars apart. These are the factors that move the number:
- Furnace size (BTU). A bigger furnace costs more equipment dollars, but the right size comes from a load calculation, not square footage alone. Oversizing wastes money up front and short-cycles the unit for years afterward.
- AFUE efficiency. AFUE (Annual Fuel Utilization Efficiency) is the percentage of fuel turned into usable heat. An 80% unit wastes 20 cents of every fuel dollar up the flue; a 96% condensing unit wastes only 4. Higher AFUE costs more to buy but lowers every heating bill.
- Staging and blower type. A single-stage furnace is either full-on or off. Two-stage and modulating units run at lower outputs most of the time for steadier comfort, and a variable-speed (ECM) blower adds quiet operation and better airflow — each step up adds cost.
- Fuel type. Gas is the most common and usually the cheapest to run; electric furnaces are cheaper to install but can cost more to operate; oil furnaces carry the highest install and maintenance overhead.
- Venting changes. Moving from an 80% to a condensing furnace means new PVC intake and exhaust piping plus a condensate drain, because the cooler exhaust can’t safely use the old metal chimney flue. That conversion can add several hundred to over a thousand dollars.
- Ductwork and electrical. Resizing plenums, adding a return, or running a new circuit and disconnect all add labor. Badly sized ducts can choke even a perfect furnace.
- Removal, disposal, permits, and region. Hauling away the old unit, pulling a permit (typically $50 to $500), and local labor rates all factor in. Labor on the coasts runs well above the national average for identical work.
What moves your furnace cost
Why Efficiency Changes the Whole Quote
The jump from a standard to a high-efficiency furnace is the decision that moves the price most, because it changes more than just the box.
An 80% AFUE furnace vents hot exhaust through a metal flue and is the cheapest to install. A 90–96% condensing furnace extracts so much heat that its exhaust is cool enough to run through PVC pipe, but it produces acidic condensate that needs a drain — which is why the conversion adds venting work. A modulating, variable-speed unit at 97–98% AFUE costs the most up front but runs in long, quiet, low-output cycles that even out temperatures and trim fuel use the most.
The right tier is a payback question. In a cold climate with a long heating season, the fuel savings from a 96% unit can repay the premium over a 80% unit within several years. In a mild climate where the furnace runs only a few weeks a year, the cheaper 80% unit often makes more financial sense. Run both scenarios through the Furnace Replacement Cost Calculator before you commit.
Repair vs Replace
You do not always need a new furnace. A single failed igniter, flame sensor, or blower motor is often a few-hundred-dollar repair on a unit with years of life left. The question is whether the furnace is fundamentally sound or near the end of its service life.
Repair is usually the better call when:
- The furnace is under about 15 years old and otherwise reliable
- The fix is a single, well-understood part and costs well under a new unit
- The unit is correctly sized and your bills have been normal
- It is still under manufacturer or labor warranty
Replacement is the better call when:
- The furnace is 15+ years old and approaching its 15–20 year life expectancy
- The heat exchanger is cracked — a safety issue and almost never worth repairing
- You are facing repeated repairs in consecutive seasons (the “$5,000 furnace, $800 a year” trap)
- Heating bills keep rising despite normal use, pointing to lost efficiency
- A major part (heat exchanger, control board, blower) fails on an aging, out-of-warranty unit
A common rule of thumb: if a single repair costs more than about a third to half of a new furnace, and the unit is past 12–15 years, replacement is usually the smarter spend over the long run.
Repair, or replace your furnace?
Signs Your Furnace Is Near the End
Furnaces rarely die in a single moment. Watch for these signs that yours is winding down:
- Age over 15 years, especially with an original single-stage unit
- Yellow or flickering burner flame instead of a steady blue, or visible soot
- Banging, rattling, or screeching on startup and shutdown
- Uneven heat — some rooms never warm up while the furnace runs constantly
- Climbing gas or electric bills with no change in weather or usage
- Frequent cycling on and off, a hallmark of an oversized or failing unit
One sign on its own may just mean a tune-up is due. Several at once, on an aging furnace, point toward planning a replacement before it fails in the middle of winter.
How to Estimate Your Job
You can build a credible estimate yourself before you call anyone. Walk it step by step:
- Get your BTU size. Run a load calculation with the Furnace BTU Calculator rather than guessing from square footage. Size sets both equipment cost and comfort.
- Pick an efficiency tier. Choose 80% for the lowest up-front cost, 90–96% condensing for lower bills, or modulating for the best comfort. Use the table above for a starting range.
- Add the venting reality. If you are moving up to a condensing unit from an 80% furnace, budget for new PVC venting and a condensate drain.
- Add ductwork and electrical. Budget for any plenum changes, a new return, or a new circuit if the install needs one.
- Add removal, permit, and a contingency. Include haul-away of the old unit, a $50–$500 permit, and 10 to 15 percent for surprises.
For example, a 90% condensing gas furnace sized at 80,000 BTU, with a standard vent conversion and easy access, lands roughly in the $5,000 to $6,500 range in most of the country — squarely in the typical band.
To skip the arithmetic, run your numbers through the Furnace Replacement Cost Calculator. If you are replacing ductwork at the same time, our guide to ductwork replacement cost puts that line item in context, and the Furnace Sizing Guide makes sure you are buying the right size in the first place.
Use the Free Calculator
Furnace Replacement Cost Calculator — get your exact answer in seconds.
Enter your home size or BTU load, pick an efficiency tier and fuel type, and the calculator returns an installed cost estimate for your job. Pair it with the Furnace BTU Calculator to lock in the right size first.
FAQ
How much does it cost to replace a furnace?
Furnace replacement typically runs $3,000 to $7,500 installed in 2026, with most gas furnace jobs landing around $4,500 to $6,000. A basic 80% AFUE unit in an easy install can come in near $3,000, while a high-efficiency modulating furnace with new PVC venting can reach $10,000 or more. The biggest drivers are the furnace’s BTU size, its AFUE efficiency, fuel type, and how much venting, ductwork, and electrical work the install requires.
How much is a high-efficiency furnace?
A 90–96% AFUE condensing gas furnace usually costs $4,500 to $7,500 installed, and a modulating, variable-speed unit at 97–98% AFUE runs $6,000 to $10,000+. The premium over a standard 80% furnace buys lower fuel bills and steadier comfort. Whether it pays off depends on your climate and heating season — the savings repay the premium faster in cold regions than in mild ones.
When should I replace vs repair my furnace?
Repair makes sense when the furnace is under about 15 years old, the fix is a single inexpensive part, and the unit is otherwise reliable. Replace when it is 15+ years old, the heat exchanger is cracked, you are facing repeated repairs, or bills keep climbing. A common rule: if one repair costs more than a third to half of a new furnace on an aging unit, replacement is usually the smarter long-term spend.
Is it cheaper to replace furnace and AC together?
Yes, replacing the furnace and air conditioner at the same time is usually cheaper per unit than doing them separately. You pay for one service visit, one round of permits and labor mobilization, and the technicians size the two units to work together as a matched system. If both pieces are aging — typically 12 to 15 years or older — bundling the replacement avoids paying twice for overlapping labor and improves overall efficiency.
What size furnace do I need?
Furnace size is measured in BTU output and should come from a load calculation, not square footage alone. As a rough anchor, a 2,000 sq ft home in a cold climate often needs around 90,000–100,000 BTU of output, but insulation, windows, climate zone, and AFUE all shift that. Use the Furnace BTU Calculator and the Furnace Sizing Guide to get the right number — oversizing is the most common and costliest mistake.