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.
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.