HVAC Replacement Cost Calculator
* Assumes existing ductwork in good condition. Final costs vary by SEER rating, brand, and labor rates.
Disclaimer: Estimates are for budgeting purposes only. Actual costs vary by location, contractor, material availability, and project complexity. Always get professional quotes for exact pricing.
HVAC Replacement Cost by Type
| Replacement Type | Cost Range | Time |
|---|---|---|
| AC Unit Only | $3,000 – $6,000 | 4–6 hours |
| Furnace Only | $2,500 – $5,500 | 6–8 hours |
| Full System | $5,500 – $11,000 | 1 day |
| Heat Pump | $5,000 – $11,000 | 1 day |
* Add $300–$800 for old system removal and $150–$500 for new thermostat.
How We Calculate
Our HVAC replacement cost calculator estimates project costs based on home size and what to replace. Assumes existing ductwork in good condition (no ductwork replacement needed).
How the math works: Tonnage = home sq ft ÷ 600. Base cost varies by replacement type (AC only, furnace only, full system, heat pump). Size adjustment = base cost × sqrt(home sq ft ÷ 2000). Removal = $300–$800 if included. Thermostat = $150–$500 if included. Total = equipment + removal + thermostat.
Replacement Options
AC Unit Only ($3,000–$6,000): Replace outdoor condenser unit, keep existing furnace. Cheapest option. Takes 4–6 hours. Best for: furnace under 10 years old, budget limited, AC failed but furnace works. Includes: outdoor unit, refrigerant lines, electrical connection, startup. Requires existing ductwork and indoor air handler.
Furnace Only ($2,500–$5,500): Replace furnace, keep existing AC. Takes 6–8 hours. Best for: AC under 10 years old, furnace failed, upgrading to high-efficiency (AFUE 95+). Includes: furnace, gas line connection (if gas), flue pipe, thermostat wiring. Add $500–$1,000 for switching fuel type (gas to electric or vice versa).
Full System ($5,500–$11,000): Replace both AC and furnace. Takes 8–12 hours (1 day). Best for: both units 12+ years old, one failed and other is old, mismatched brands/sizes. Saves 10–15% vs replacing separately (shared labor, permits). Includes: outdoor AC unit, indoor furnace/air handler, refrigerant lines, electrical, thermostat wiring, startup. Matched system improves efficiency.
Heat Pump ($5,000–$11,000): Replace both AC and furnace with all-in-one heat pump. Heating + cooling in one system. Best for: moderate climates, energy savings (3× more efficient than furnace), federal tax credit ($2,000). Works in cold climates down to -15°F (newer models). Eliminates furnace — lower maintenance costs.
Additional Costs
Old system removal ($300–$800): Disconnect and remove old equipment, recover refrigerant per EPA rules (illegal to vent), haul away old units, disposal fees. Required in most cities. Some contractors include free removal with replacement.
Thermostat ($150–$500): Programmable thermostat $150–$250, smart thermostat (Nest, Ecobee) $250–$500. Smart thermostats save 10–15% on energy, remote control via app, learning schedules. Old thermostats (mercury) often incompatible with new systems. Many HVAC contractors include basic thermostat with installation.
Not included: Ductwork replacement ($2,000–$5,000 if needed), electrical panel upgrade ($1,000–$3,000 if undersized), permits ($100–$500, usually included in quote), gas line extension ($500–$2,000 if needed).
Data Sources
Pricing from HomeAdvisor, Angi, and verified HVAC contractor estimates. Sizing guidelines per ACCA Manual J standards. We review and update regularly.
Last updated: 2026-02-09
Frequently Asked Questions
How much does HVAC replacement cost? +
HVAC replacement costs $3,000–$11,000+ depending on what you replace. AC unit only costs $3,000–$6,000, furnace only $2,500–$5,500, full system (AC + furnace) $5,500–$11,000, heat pump $5,000–$11,000. Add $300–$800 for old system removal and $150–$500 for new thermostat. Replacement is cheaper than new installation since ductwork is already installed.
Should I replace just the AC or the whole system? +
Replace full system (AC + furnace) if: both units are 12+ years old, one unit fails and other is old, mismatched brands/sizes (inefficient), upgrading to high-efficiency saves 20–40%. Replace AC only if: furnace is under 10 years old and working well, budget limited (spread costs over time), switching to heat pump later. Matching indoor/outdoor units (same brand, SEER) improves efficiency 10–15%.
How long does an HVAC system last? +
Central AC lasts 15–20 years. Gas furnace lasts 15–30 years (longer than AC). Heat pump lasts 15 years. Signs to replace: frequent repairs (over $1,000/year), age over 15 years, rising energy bills, uneven temperatures, R-22 refrigerant (phased out, expensive). Replace before failure to avoid emergency costs (20–30% higher) and loss of heating/cooling.
Can I replace HVAC myself? +
No. HVAC replacement requires: EPA 608 certification (handle refrigerant legally), electrical license, HVAC contractor license, specialized tools ($2,000+), permits ($100–$500). DIY risks: refrigerant leaks (illegal $10,000 fine), electrical fires, voided warranty (labor + parts), failed inspection. Average DIY attempt costs more after hiring pro to fix mistakes. Hire licensed HVAC contractor — replacement takes 1 day.
What SEER rating should I get for replacement? +
Standard replacement: 14–16 SEER ($3,000–$5,000), meets code, good value. High-efficiency: 18–20 SEER ($5,000–$6,500), saves 20–30% on cooling, qualifies for $300–$600 rebates, payback in 8–12 years. Premium: 21+ SEER ($6,500+), best for hot climates or large homes. Higher SEER costs $300–$500 per SEER point but lowers bills $100–$200/year. Choose 16+ SEER if keeping home 10+ years.
Do I need to replace both indoor and outdoor units? +
Best practice: replace both indoor (air handler/furnace) and outdoor (condenser) units together for: matched efficiency (10–15% better performance), warranty protection (many brands void warranty if mismatched), proper sizing (old systems often oversized), reliable operation. Exception: replace outdoor only if indoor unit is under 5 years old and same brand/capacity. Mismatched systems reduce efficiency and lifespan.
Should I get quotes from multiple HVAC contractors? +
Yes, always get 3+ quotes. Prices vary 20–40% between contractors. Compare: equipment brand/model (Carrier, Trane, Goodman), SEER rating, warranty (10 year parts, 1–10 year labor), included services (removal, permits, thermostat). Red flags: no Manual J load calculation, quote over phone without inspection, pressure to decide immediately, cash-only deals. Licensed contractors required for permits and rebates.
Are there rebates for HVAC replacement? +
Yes. Federal tax credit: 30% of cost up to $2,000 for heat pumps, $600 for AC/furnace (installed 2023–2032, ENERGY STAR certified). Utility rebates: $300–$1,000 for high-efficiency systems (check local utility website). State rebates: $500–$3,000 in CA, NY, MA. Manufacturer rebates: $200–$500 during promotions (spring/fall). Requirements: SEER 16+, HSPF 8.8+, professional installation. Apply after installation with receipts.
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