Furnace replacement cost in 2026: the honest ranges and where quotes pad
A straight swap runs $3,500–8,000 installed for most homes. Here is what moves the number and the questions that keep a quote honest.
Ranges below are for replacing a gas furnace in an existing US home, including removal, install, and permit. High-cost metros land toward the top. If ductwork, gas line, or electrical need real changes, those are legitimate adders — but they should be itemized, not buried.
| Item | Typical range | Note |
|---|---|---|
| 80% AFUE single-stage | $3,500–5,500 | The workhorse replacement |
| 96%+ AFUE two-stage | $5,000–8,000 | New PVC venting included |
| Variable-speed / modulating | $6,500–10,000+ | Comfort tier, longest payback |
| Ductwork corrections | add $1,000–5,000 | Only with a measured reason |
| Chimney liner (80% into old flue) | add $750–2,000 | Code-driven, ask why |
Efficiency math without the sales gloss
Going from an old 80% furnace to a 96% unit saves roughly 16 cents of gas per dollar you used to burn. On a $900/season gas bill that is ~$145/year — real money, but a $2,000 price jump takes 13+ years to pay back on fuel alone. Cold climates and big houses shorten that; mild climates may never reach it. Run your own bill through that arithmetic before paying for the efficiency tier.
Sizing is the question that separates good installers
A good contractor measures the house or runs a Manual J load calculation. A lazy one copies the old furnace's size — which was probably oversized when it was installed. Oversized furnaces short cycle, heat unevenly, and die younger. If nobody asked about your square footage, insulation, or windows, that is the tell.
Getting quotes that can be compared
Three quotes, each itemizing equipment model number, labor, permit, venting, and any duct/gas/electrical work. Model numbers matter: "high-efficiency furnace" on a quote can hide a builder-grade unit at a premium price. And replacement quotes in January cost more than the same job in July — if the old furnace is limping rather than dead, schedule the swap off-season.
When replacement genuinely wins
Cracked heat exchanger (verified on camera), any repair over ~$1,500 on a unit past 15 years, or the age-times-repair rule from our repair-cost guide crossing $5,000. Otherwise, most single-part failures on a sub-12-year furnace are repairs, not replacements — whatever the sticker on the visit says.
Where the money goes in an install
Unlike a repair, most of a replacement quote is not the box. The same furnace model can land thousands apart between two houses because of what surrounds it: a furnace in an open basement swaps in a day, while one in an attic, crawlspace, or closet adds real labor hours; a 96% unit needs its PVC venting run to an outside wall and its condensate handled, which is cheap on some floor plans and not on others; and the code-driven adders in the table — chimney liner, duct corrections — exist because inspectors require them, not because the installer padded. That is also why the honest quote itemizes: equipment, labor, permit, venting, and adders each on their own line lets you see which part of your number is the house and which part is the market.
Codes that lead here
No fault code means "replace the furnace" by itself — none of the code families this site documents flag the heat exchanger, and that diagnosis comes from a technician's inspection, not from the board. The codes that most often start the replacement conversation are the expensive ones arriving on an old unit: a variable-speed blower quote or an OEM control board on a 15-year-old furnace fails the age-times-repair rule from our repair cost guide. Repeated limit or rollout trips belong in the conversation too — those hub pages stress that the switch is rarely the fault, and the when-to-stop guide covers the conditions that mean shut the furnace down rather than reset it again.
Know the fault code before you call
If the furnace is flashing its diagnostic LED, count the pattern and look the code up by brand here. Walking into the quote knowing what the furnace says is wrong is the cheapest leverage a homeowner has.
Look up your exact code first
Repair pricing depends on which part actually failed — the error code tells you. Find yours by brand: Carrier · Goodman · Lennox · Rheem · Trane · York · Armstrong / AirEase / Concord / Ducane · Heil / Tempstar / Comfortmaker.
Sources
- Price ranges on this page are editorial estimates of typical US installed pricing for replacing a gas furnace in an existing home, including removal and permit, stated as ranges because labor rates, access, and code requirements vary by market and by house. They are not quotes.
- The efficiency payback figures are straight AFUE arithmetic — moving from 80% to 96% AFUE burns roughly 16% less gas for the same delivered heat — applied to your own gas bill; no fuel-price forecast is assumed.
- Fault-code meanings on linked pages come from the manufacturer service documentation cited on each page.