Replacing a gas furnace typically costs about 3,500 to 8,000 USD installed for most homes, while an electric furnace is often 2,500 to 6,000 USD. High-efficiency condensing furnaces (95%+ AFUE) with two-stage or modulating burners cost more, and installations that need new venting, gas lines or ductwork add to the total.
Quick answers
- Gas furnace (80% AFUE): often 3,000–5,500 USD installed.
- Gas furnace (95%+ AFUE, condensing): often 4,500–8,500 USD.
- Electric furnace: often 2,500–6,000 USD.
- Switching from 80% to 95%+ often requires new PVC venting and a condensate drain.
- Get quotes with model numbers and AFUE ratings.
Typical price ranges
| Furnace type | Typical installed range |
|---|---|
| Electric furnace | 2,500–6,000 USD |
| Gas, 80% AFUE, single-stage | 3,000–5,500 USD |
| Gas, 95–97% AFUE, single-stage | 4,500–7,000 USD |
| Gas, 96%+ AFUE, two-stage variable-speed blower | 5,500–8,500 USD |
| Gas, modulating, premium | 7,000–11,000+ USD |
| Oil furnace | 5,500–10,000 USD |
These are planning ranges for replacements in existing ductwork. Local prices vary.
What adds to the cost
- Venting changes: going from an 80% furnace (metal flue) to a condensing furnace requires PVC venting and may leave a water heater needing a liner for the old chimney.
- Condensate drain or pump for high-efficiency furnaces.
- Gas line upgrades if the new furnace needs more capacity.
- Ductwork modifications to fit the new furnace or fix airflow problems.
- AC coil compatibility: if the existing AC coil doesn’t fit or match, it may need replacement.
- Attic or crawl space installation.
- Permits and inspections.
Is a high-efficiency furnace worth it?
It depends on your climate and gas price. In a cold climate with high heating bills, the savings from 96% vs 80% AFUE can pay back the higher price within several years. In mild climates, the payback may be very long.
| Annual gas heating bill (80% furnace) | Approximate yearly savings at 96% AFUE |
|---|---|
| 600 USD | ~100 USD |
| 1,200 USD | ~200 USD |
| 2,000 USD | ~335 USD |
Savings are estimated as the reduction in fuel used: 1 − (80 ÷ 96) ≈ 17%.
Gas or something else?
If your AC is also old, compare a heat pump or dual-fuel system before replacing like-for-like. See Heat Pump vs Furnace and Gas vs Electric Furnace.
How to avoid overpaying
- Get a load calculation, not a size based on the old furnace. (What Size Furnace Do I Need?)
- Collect at least three quotes with model numbers.
- Ask what’s included: removal, venting, condensate, permit, thermostat, warranty registration.
- Replace before it fails, ideally in spring or early fall.
- Check utility rebates for high-efficiency equipment.
Quote checklist: How to Compare HVAC Quotes.
Frequently asked questions
How long does furnace installation take?
Usually 4 to 10 hours for a straightforward replacement.
Can I replace the furnace without replacing the AC?
Yes, if the AC coil is compatible with the new furnace and in good condition. If the AC is old, replacing both together can save labor.
How long will a new furnace last?
Typically 15 to 25 years. See How Long Do Furnaces Last?
Related guides
- AC Replacement Cost in 2026
- Furnace Not Igniting
- Water Heater Replacement Cost (Tank, Tankless and Heat Pump)
Prices are typical ranges for planning purposes and vary by region, home and contractor. Always get written quotes.