Furnace Replacement in Elgin & the Fox Valley

Signs It’s Time to Replace Your Furnace

Not every old furnace needs to go. These are the signs that tell us the money is better spent on a new one.

• It is 15 to 20 years old or more. A gas furnace typically lasts 15 to 20 years. Past that, every winter is borrowed time, and parts get harder to find.
• The heat exchanger is cracked or rusted through. This is the one sign that ends the conversation. A cracked exchanger can push carbon monoxide into your air, and on an older furnace the swap costs more than it is worth.
• The repair quote is more than half of a new furnace. Big-ticket blower motors, control boards or inducer assemblies on an old unit rarely pay back.
• You’ve had two or three repairs in the last couple of winters. Furnaces wear out as a whole. Once the failures start stacking up, the next one is coming.
• It is an 80% furnace and your gas bills keep climbing. Roughly one in five dollars goes up the flue on an 80% furnace. A 97% AFUE replacement burns about 17% less gas for the same heat, and an old furnace that has lost efficiency does even worse than its label.
• Rooms are cold, humidity is off, and it runs constantly. A single-stage blower on a tired furnace cannot keep a split-level even. Two-stage or modulating replacements fix comfort problems a repair never will.
• It short cycles or is too loud to talk over. An oversized furnace slams on and off. An old blower shakes the ductwork. Both are sizing and equipment problems, not part problems.
• Rust, soot or scorch marks around the burner compartment. Signs of years of flame rollout, condensation or poor combustion, all of which shorten what’s left.
• You’re adding a heat pump. A new dual-fuel system pairs a cold-climate heat pump with a matching furnace and a control that switches between them. It is often the right time to replace an old furnace at the same time.
• You want to stop worrying about it. A new furnace with a registered warranty and a maintenance plan is the difference between a January night you sleep through and one you don’t.

Smell gas? Leave the house right away, call 911 from outside, and call your gas utility’s emergency line from outside before calling us.

Repair or Replace: The Math We Use

We give you a price for both options on the same visit, and we’re honest about which one we’d pick for our own house.

The 50% rule is the starting point: if a repair costs more than half of what a replacement would, replace. Then layer in age. The table below is how we think about it. It is not a formula, but it is close to how the decision usually lands.

Two more factors tip the scale. First, an 80% furnace at 15 years is a stronger replacement candidate than a 95% furnace at 15 years, because the efficiency jump pays for part of the new unit. Second, if you are planning a heat pump, an AC replacement or finishing the basement, doing the furnace at the same time saves a second install day and a second permit. Need it fixed today instead? See furnace repair.

What Changes With a New Furnace

The difference between a 2005 furnace and a 2026 furnace is bigger than most people expect.

What a Furnace Replacement Includes

A new furnace is only as good as the installation behind it.

An Amana gas furnace with an AprilAire air filter, installed by our team.

• A new furnace sized to your home, not to the old unit’s label; Manual J load calculation available on request
• High-efficiency Amana and Daikin gas furnaces in two-stage, modulating and variable-speed options
• New PVC intake and exhaust venting on condensing furnaces, sloped and terminated to code
• Gas line, shutoff, drip leg and flex connector inspected or replaced
• Condensate trap, drain and pump, with a neutralizer where needed
• Sheet metal transitions to your existing ducts and a properly sized return and filter cabinet
• Thermostat options, including qualifying ENERGY STAR smart models that raise the Nicor Gas discount
• Permit filed under our own license where your municipality requires it
• Old furnace disconnected, removed and hauled away
• Startup and commissioning with combustion analysis, gas pressure, temperature rise and static pressure recorded
• Warranty registered for you, and the Nicor Gas discount taken off the invoice

For the full step-by-step of how we size, vent and commission a furnace, see furnace installation. Paying over time? Prequalify in about 2 minutes with no impact to your credit score.

How Replacement Day Goes

You’ll have heat again the same day on almost every changeout.

Before the day. A free in-home visit comes first. We measure the house, look at the ducts, venting, gas line and electrical, talk through two-stage versus modulating and whether a heat pump makes sense, and leave you a written quote with the discount already subtracted. No pressure, and the quote is good for you to compare. Request a free quote.

Morning. The crew arrives, lays down floor protection, shuts off gas and power and disconnects the old furnace. Old venting comes out, and if you had an 80% furnace sharing a metal flue with the water heater, we reline or resize that flue so the water heater vents safely on its own. The old furnace goes on the truck.

Midday. The new furnace is set, leveled and connected: sheet metal transitions to the supply and return, new PVC intake and exhaust through the rim joist, gas line with a new drip leg and shutoff, condensate drain and trap, and a dedicated electrical connection. A new filter cabinet goes in if the old one was undersized.

Afternoon. Startup and commissioning. We set manifold gas pressure, run combustion analysis, set blower speeds to hit the rated temperature rise, measure static pressure, and test every safety. You get the readings on the invoice. Then we walk you through the thermostat, the filter and what the furnace should sound like.

Afterward. The permit inspection is scheduled where your town requires one, the warranty is registered in your name, and the Nicor Gas discount shows as a line on the invoice. Most single-furnace changeouts take one working day. Adding a heat pump, relocating the furnace or running new ductwork can add a day.

What Furnace Replacement Costs and How the Discount Works

Every quote is free, written, and shows the Nicor Gas discount subtracted, so the number you see is the number you pay.

Replacement pricing depends on the furnace’s size and stage, the efficiency tier, the venting work, whether the ductwork or gas line needs changes, and your town’s permit. We don’t publish a single installed price because the same furnace costs different amounts in different basements. What we do promise is one written price, no surprise add-ons, and the discount figured before you sign.

The Nicor Gas math. As a Nicor Gas Contractor Circle Installing Member we apply the 2026 instant discount right on the invoice: $225 on a furnace rated 97% AFUE or higher, or $150 at 95% AFUE. Add a qualifying smart thermostat on the same invoice and the total becomes $275 or $200. There is no rebate form and no waiting for a check. See Nicor Gas instant discounts.

Financing. You can prequalify in about 2 minutes with no impact to your credit score, and the discount lowers the amount you finance. On-bill financing is another option for qualifying equipment.

After the install. The $240 maintenance plan covers the fall furnace tune-up and the spring AC or heat pump tune-up, keeps the warranty paperwork clean, and gives you priority scheduling and 5% off services.

Furnace Replacement Across the Fox Valley

Based in Elgin, we serve homes throughout Kane, McHenry, DuPage and DeKalb counties.

• Elgin
• South Elgin
• St. Charles
• Aurora
• Bartlett
• Streamwood
• Huntley
• Plato Center
• Sycamore
• Carpentersville
• West Dundee
• East Dundee
• Algonquin
• Gilberts
• Hampshire
• Pingree Grove
• Campton Hills
• Geneva
• Batavia
• Barrington
• Hoffman Estates
• Schaumburg
• Burlington
• Marengo
• Wayne
• Sleepy Hollow

Don’t see your town? Call (847) 224-2420. View all service areas.