The first thing most people want to know when a furnace quits is what the replacement is going to run. Nobody can give you a real number without seeing the house. But we can tell you what the industry cost guides are reporting for 2026, which parts of the job move the price the most, and how buying the equipment yourself fits into the picture.
One note before the numbers. The ranges below come from published industry cost guides, not from our price list. They include the installer’s labor, materials and markup, and they vary a lot by region. Treat them as a sanity check on a quote, not a quote.
What cost guides are reporting for 2026
The published ranges are wide because a furnace swap can be a two-hour bolt-in or a full day of rework. Here is what a few of the better-known guides list:
| What’s included | Typical range reported | Source |
|---|---|---|
| Gas furnace, installed (unit, labor, removal, permits) | $3,800 to $12,000 | HomeServe, Feb 2026 |
| Gas furnace, installed | $3,800 to $10,000 | This Old House, June 2026 |
| High-efficiency gas furnace (90% to 98% AFUE), installed | $3,800 to $11,500 | HomeServe, Feb 2026 |
| Electric furnace | $2,000 to $7,000 | This Old House, June 2026 |
| Standard gas furnace, unit only | $700 to $6,200 | HomeServe, Feb 2026 |
Look at the gap between the unit-only line and the installed lines. On a lot of furnace jobs, the equipment is the smaller part of the bill.
What actually moves the price
Efficiency (AFUE)
AFUE is the share of the fuel’s heat that ends up in your house. An 80% furnace sends about a fifth of it up the flue. A 95% or 96% furnace keeps almost all of it, and it does that by pulling extra heat out of the exhaust until the water vapor condenses.
The higher-efficiency furnace costs more to buy. Whether it pays you back depends on how cold your winters are and what you pay for gas. In north Georgia, plenty of homes do fine with 80%. Up north, the math usually favors 92% and above. Our good, better, best guide goes into who each one fits.
Going from 80% to 90%+ means new venting
This is the one that surprises people. An 80% furnace vents hot exhaust through a metal flue, usually into a chimney or a B-vent. A condensing furnace (90% and up) runs cool, wet exhaust through PVC pipe, typically with a second pipe for combustion air, and both usually go out through a side wall or the roof. It also needs a condensate drain, and sometimes a condensate pump.
So the first time a house moves from 80% to a condensing furnace, the installer has to run new pipe and cut new penetrations. There’s a second catch if a gas water heater shares that old chimney. Take the furnace off the flue and the water heater can be left venting into a chimney that’s now too big for it. That can mean a liner or other changes. Ask your contractor about it up front so it’s in the quote and not a surprise.
Going the other way, from a condensing furnace back to an 80%, isn’t simple either. The PVC can’t be reused, because an 80% furnace needs a proper metal flue sized for it.
Size (BTU input)
A bigger furnace costs more, but the bigger cost risk is buying the wrong size. Oversized furnaces short-cycle and run loud. Undersized ones run all night and still leave you cold in January. The right size comes from a load calculation, not the sticker on the old unit. Our sizing guide explains why.
Ductwork
If the ducts are in decent shape, the new furnace connects to what’s there. If they leak or the return is undersized, expect added cost. HomeServe lists duct leak repair at roughly $200 to $700, and new duct runs at roughly $270 to $500 per run. Some installers will also need a transition piece if the new cabinet is a different width than the old one.
Permits and code items
Most areas require a mechanical permit for a furnace replacement. HomeServe puts permit fees at about $50 to $300 depending on the county. Code upgrades can add to it: gas line changes, a new shutoff, a drain pan, a disconnect.
Access and labor rates
A furnace in an open basement is a different job than one in a hot attic or a tight crawlspace. Local labor rates matter too. Guides commonly cite $75 to $150 an hour for HVAC labor, and most contractors quote the job as a flat price anyway.
Replacing the coil at the same time
If you have central air, the evaporator coil sits on top of the furnace. Sometimes it can stay. Often it can’t, because the new furnace is a different width or the coil is old and matched to an outdoor unit that’s near the end too. If your AC is 12 or more years old, read our repair vs. replace guide before you replace the furnace alone.
Buying the furnace yourself and hiring an installer
A lot of our customers buy the equipment from us and hire a licensed contractor to put it in. We don’t do installs. We sell the equipment, ship it to you, and help you pick the right model. Here’s how that usually goes:
- Get the model numbers off your current equipment. Furnace, coil and outdoor unit if you have one. Our guide on reading a furnace model number will tell you the BTU input and efficiency.
- Talk to an installer first. Ask if they’ll install customer-supplied equipment and what they charge for labor alone. Some will, some won’t, and that’s fine. You want to know before you buy.
- Pick the furnace. Match the venting your house has (or plan for the venting change), the airflow direction (upflow, downflow or horizontal) and the cabinet width. Call us if you’re not sure.
- Schedule delivery. Furnaces ship by LTL freight. The carrier calls to set a time, and someone has to be there to sign. Inspect every carton before you sign. Our delivery checklist walks through it.
- Install and register. Have it installed by a licensed contractor to the manufacturer’s instructions and local code. Then register the warranty. Goodman requires registration within 60 days of installation for the full warranty.
Done this way, you see what the equipment costs and what the labor costs as separate numbers. That alone makes quotes easier to compare.
The federal 25C tax credit is gone for equipment installed after December 31, 2025, so don’t count on it when you budget. Some utilities still offer rebates, so check with yours.
Common questions
Is the furnace or the labor the bigger part of the cost?
On many jobs it’s the labor and materials. Published guides list standard gas furnaces at roughly $700 to $6,200 for the unit alone, against $3,800 to $12,000 installed. The gap is labor, venting, permits and the installer’s overhead.
Why does a 95% furnace cost so much more to install than an 80%?
If you’re replacing an 80% furnace, the condensing furnace needs PVC venting, usually a combustion air pipe, and a condensate drain. That’s new pipe and new holes in the house. If you already have a condensing furnace, the difference is much smaller.
Can I install a furnace myself?
We recommend a licensed HVAC contractor. Gas and venting work usually requires a permit, and manufacturers can void the warranty if the unit isn’t installed by a licensed contractor to their instructions and local code.
Do I need to replace my AC coil with the furnace?
Not always. If the new furnace is the same width and the coil is in good shape and matched to your outdoor unit, it may stay. If the AC is older or the coil doesn’t fit, it often makes sense to replace them together.
Want help picking the right furnace for your house? Call us at (877) 843-4822, or browse gas furnaces.