HVAC Replacement Cost: Furnace, AC, or Both
Replacing a furnace runs $2,500 to $6,500 and a central air conditioner $3,500 to $7,800. Doing both at once typically costs $8,000 to $15,000 — but usually saves 15–20% versus two separate jobs.
Replacing one component
Furnaces and air conditioners have different lifespans: roughly 15–20 years for a furnace, 10–15 for a central AC, so they don't always fail together. Replacing just one is common.
| System | Installed cost |
|---|---|
| Gas furnace | $2,800 – $6,500+ |
| Electric furnace | $2,000 – $5,500+ |
| Central air conditioner | $3,500 – $7,800+ |
| High-efficiency furnace (95%+ AFUE) | $3,500 – $6,500 |
Replacing both at once
If both units are near end of life, bundling is usually the better economic call: you pay one mobilization of labor instead of two, and manufacturers often tie rebates to matched systems.
| Bundle | Installed cost |
|---|---|
| Entry level (standard efficiency) | $7,000 – $11,000 |
| Premium (high efficiency) | $12,000 – $17,000+ |
Multiple independent sources put a full furnace-plus-AC replacement in the $8,000–$15,000 band, with bundling saving roughly 15–20% compared to two separate installations.
What pushes the number up
- Ductwork condition: if existing ducts are undersized, leaking, or absent, this can add thousands and is the most common source of quote variance between contractors.
- System sizing: a proper load calculation (Manual J) matters more than brand. An oversized system short-cycles, wears out faster, and dehumidifies poorly.
- Efficiency rating: higher AFUE/SEER equipment costs more upfront; whether it pays back depends on your climate and energy prices.
- Electrical or gas line work if you're changing fuel type or capacity.
Is your quote reasonable?
For a standard-efficiency furnace and AC bundle in an average home with usable existing ductwork, expect $7,000–$11,000. Quotes well above that should come with a specific reason: high-efficiency equipment, duct replacement, or a difficult install location. Ask for the load calculation; a contractor who sizes by square footage alone is guessing.