Furnace replacement cost by type
| Job | What's included | Typical market range | Fair price* |
|---|---|---|---|
| Gas furnace, 80% AFUE | 80% AFUE single-stage gas furnace, ~80k BTU · Removal and haul-away of old furnace · Reconnect existing venting, gas and ductwork · Startup, combustion and CO test | $3,800–$6,200 | $4,900 |
| Gas furnace, 96% AFUE | 96% AFUE condensing gas furnace, ~80k BTU · New PVC intake/exhaust venting and condensate drain · Removal and haul-away of old furnace · Startup, combustion and CO test | $4,600–$12,000 | $6,600 |
| Electric furnace / air handler | Electric furnace with heat strips, sized to existing circuit · Removal and haul-away of old unit · Reconnect existing ductwork | $1,500–$5,100 | $3,400 |
*National base price before local adjustment and add-ons. Prices are current estimates while our provider network finalizes local pricing. Market ranges come from published contractor prices and national cost guides (sources). Updated October 2026.
Replacing your AC at the same time? Bundles cost less than two separate jobs. See AC and furnace replacement.
What’s included, and what costs extra
| Add-on | When you need it | Fixed price |
|---|---|---|
| Permit & inspection | Required in most cities for HVAC change-outs. Your pro pulls it. | $225 |
| Vent pipe replacement | If the existing flue is rusted, undersized or not to code. | $450 |
| Gas line upsizing / new shutoff | Common for tankless conversions. Covers up to about 25 ft of new pipe. | $650 |
| Attic / crawlspace / tight-closet access | Extra labor when the unit is hard to reach. | $375 |
| New smart thermostat | Installed and paired. | $275 |
| Condensate pump | When there's no floor drain nearby. | $275 |
| Same-day / after-hours service | Book for today, or evening and weekend slots. | $250 |
Check these before you replace (DIY)
- Change the filter. A clogged filter can overheat the furnace and trip its high-limit safety switch, so it shuts off.
- Check the thermostat: it should be set to “Heat,” set above room temperature, and have fresh batteries.
- Check the power. Look for the furnace switch (it looks like a light switch, near the unit) and the breaker.
- Check the gas. Make sure the gas valve to the furnace is open and other gas appliances work.
- Read the status light. Most modern furnaces blink an error code through a small window in the panel, with a code chart on the door. Look up your code: Carrier, Goodman, Trane / American Standard, Lennox.
- Clean the flame sensor. A dirty sensor makes the burners light, then shut off within seconds. With power off, remove the sensor and gently clean it with fine steel wool or a fine abrasive pad. Only do this if you’re comfortable working inside the furnace.
Smell gas or your CO alarm sounds? Leave the house immediately and call your gas utility or 911 from outside.
Signs it’s time to replace your furnace
- It’s 15–20 years old, and repairs are getting frequent or expensive.
- A technician found a cracked heat exchanger.
- Rooms heat unevenly, or your gas bills keep climbing for the same usage.
- You’re replacing the AC and the furnace blower is near end of life.
80% vs 96% AFUE furnaces
AFUE (Annual Fuel Utilization Efficiency) is the share of the gas that becomes heat in your home. An 80% furnace vents hot exhaust up a metal flue. A 96% furnace condenses the exhaust to capture more heat, so it needs PVC venting and a condensate drain.
| 80% AFUE | 96% AFUE | |
|---|---|---|
| Installed price | $4,900 | $6,600 |
| Heat from each dollar of gas | 80¢ | 96¢ |
| Venting | Existing metal flue | New PVC (sidewall or roof) |
| Best for | Mild winters | Cold winters |
Heat pumps are another option for both heating and cooling. See heat pump replacement costs.
Frequently asked questions
How much does it cost to replace a furnace?
A fair price for furnace replacement is $3,400–$6,600 installed, depending on fuel and efficiency. An 80% gas furnace is $4,900 and a 96% high-efficiency gas furnace is $6,600.
How long does a furnace last?
Gas furnaces commonly last around 15–20 years with regular maintenance. Rising repair costs, uneven heating, and a cracked heat exchanger are common signs it’s time to replace.
Is a cracked heat exchanger dangerous?
It can be. A cracked heat exchanger can let combustion gases, including carbon monoxide, mix with the air in your home. If a technician finds one, stop using the furnace, and make sure you have working CO alarms.
Should I choose an 80% or 96% furnace?
In colder climates with long heating seasons, a 96% condensing furnace usually pays back through lower gas bills. In mild climates, an 80% furnace is often the better value. It also costs less to install, because it can reuse the existing flue.
Do I need a permit to replace a furnace?
In most US cities, yes, because it involves gas, venting and electrical connections. Your pro pulls the permit, and it’s listed as an add-on in our price tool.