Furnace replacement · Aurora, IL
Furnace replacement in Aurora, IL
The short answer
A furnace replacement in Aurora, IL runs $5,000–$9,000 installed: about $5,000–$7,000 for a standard 80% AFUE furnace, and $6,300–$9,000 for a 95%+ high-efficiency unit with new PVC venting. Most swaps take one day. The price covers Manual J and Manual D sizing, removal of the old furnace, the permit with whichever of Aurora's four counties covers your address, and a combustion analysis at startup.
Written by Jenna Fortman, Owner of FortHouse Heating & Cooling. Installed by EPA 608 and NATE-certified technicians.
What does furnace replacement cost in Aurora?
| Option | AFUE | Installed price | Venting and scope |
|---|---|---|---|
| Standard efficiency | 80% | $5,000–$7,000 | Uses the existing metal flue |
| High efficiency | 95%+ | $6,300–$9,000 | New PVC venting and a condensate drain, included |
| Ductwork changes | — | +$800–$2,500 | Only if the existing ducts can't carry the new furnace's airflow |
AFUE is the share of the gas you pay for that ends up as heat in the house. An 80% furnace sends about a fifth of it up the flue; a 95% furnace sends about a twentieth. Which one pays back depends on your house and your gas bills, so we run that math during the sizing visit.
Repair or replace: how do you decide?
Multiply the furnace's age by the repair cost. Over $5,000, replacement usually wins. Separately, if one repair costs more than half of a new furnace, replace. A cracked heat exchanger or a second repair in the same season pushes toward replacement even when the math is close.
| Furnace age | Repair quote | Age × cost | Verdict |
|---|---|---|---|
| 8 years | $400 | $3,200 | Repair |
| 12 years | $450 | $5,400 | Close — check the 50% rule too |
| 16 years | $600 | $9,600 | Replace |
What happens on installation day?
Before install day
Sizing visit
A Manual J load calculation on the house and a Manual D check on the ducts, so the new furnace fits the house instead of copying the old unit's size.
Written quote
Furnace tier, venting, and any duct work, priced in writing before any work starts.
Permit filed
Filed with whichever of Kane, DuPage, Will, or Kendall County covers your address.
Install day
Old furnace out
Disconnected, removed, and hauled away. Removal is in the price.
New furnace in
Set, with the venting, gas line, and combustion air done to code.
Startup and combustion analysis
Measured combustion readings at startup, written down and left with you.
After
County inspection
The inspector signs off on the permit. We schedule it; you don't have to call anyone.
Why is furnace replacement different in Aurora?
Four counties
Aurora spans four counties — Kane, DuPage, Will, and Kendall — and a furnace replacement is permitted work filed with whichever one covers your address. We confirm the county before quoting, so the permit isn't what holds up installation day.
Pre-1939 housing
Downtown Aurora and its historic districts have more pre-1939 housing than 97.5% of neighborhoods nationwide, and much of it runs on ductwork from a decades-old retrofit. A new furnace that pushes more air than those ducts can carry ends up loud and uneven, which is why the Manual D duct check happens before the furnace is picked, not after it's installed.
Fox River basements
A 95%+ furnace produces condensate that has to drain somewhere. In a basement near the Fox River that already fights moisture, where that line runs is part of the written quote, not a decision made on installation day.
Questions Aurora homeowners ask
How much does a new furnace cost in Aurora, IL?
$5,000–$9,000 installed. A standard 80% AFUE furnace runs about $5,000–$7,000 and vents through the existing metal flue. A 95%+ high-efficiency furnace runs about $6,300–$9,000, including the new PVC venting it needs. If the ductwork has to change, that adds $800–$2,500, quoted separately in writing.
How long does furnace replacement take?
Most standard swaps finish in one day. Before that day there's a sizing visit and a written quote, and we file the permit with your county, so installation day is just the removal, the install, and the startup test.
Do I need a permit to replace a furnace in Aurora?
Yes. Furnace replacement is permitted work, and because Aurora spans Kane, DuPage, Will, and Kendall counties, the permit goes to whichever office covers your address. We file it and schedule the inspection as part of the job.
Should I get an 80% or a 95% efficiency furnace?
An 80% furnace costs less up front and reuses the existing metal flue. A 95%+ furnace costs more, needs new PVC venting and a condensate drain, and burns less gas every winter. The sizing visit and your actual gas bills decide which one pays back in your house; we show you that math before you choose.
When should I replace my furnace instead of repairing it?
Replace when a repair costs more than half of a new furnace, or when the furnace's age times the repair cost tops $5,000. ENERGY STAR recommends a professional evaluation once a furnace passes 15 years. If the math still favors a fix, Aurora furnace repair is the better call.
Can you replace the furnace and the AC at the same time?
Yes, and it often costs less per system because the labor, permit, and sizing work overlap. We still check each system on its own first, so a healthy AC doesn't get replaced just because the furnace failed. See AC installation in Aurora for the cooling side.
Sources
Prices are FortHouse's own published installed ranges, last updated September 23, 2026. Your written quote follows a home visit, not a phone call.
Book a visit
(630) 318-6246