Furnace Replacement Cost (Illinois)
Typical market range as of May 2026 · regionalized for northern Illinois
Most homeowners
$4,800
Replacing a gas furnace in Illinois typically runs $3,000–$9,000 installed, with most homeowners around $4,500–$5,000. The big swings are efficiency tier (a basic 80% AFUE single-stage unit vs. a 95%+ two-stage or modulating furnace), the size your home actually needs, and any venting or gas-line work the new unit requires.
Pricing this job, not hiring for it? See what the work is worth →What drives the price
Efficiency (AFUE)
An 80% single-stage furnace is the budget end; 95%+ AFUE two-stage and modulating furnaces cost more but cut gas bills in a cold climate.
Sizing (BTU)
A correctly sized furnace — by a load calc, not a guess — matters more than brand. Oversizing wastes money and short-cycles.
Venting changes
Switching to high-efficiency means PVC sidewall venting and a condensate drain — added labor over a like-for-like swap.
Permits & labor
Chicago-area municipalities often require permits and inspection, and regional labor rates run $85–$110/hr.
In our market — McHenry County & northern Illinois
Northern Illinois is a heating-dominated climate, so furnace sizing and efficiency matter more here than in mild regions. McHenry County installs commonly run $3,500–$7,000 depending on tier, and Chicagoland pricing tends to sit slightly above the national average due to permitting and labor. Peak-season (Nov–Feb) replacements can carry a premium — replacing a tired furnace in the shoulder season is usually cheaper.
Walk in informed
Get the BTU sizing from an actual load calculation, not a 'same as the old one' rule of thumb — and get itemized quotes from more than one tech. A high-pressure same-day 'today only' price on a $5,000 furnace is a reason to slow down.
Fair Price Guide is iHVAC's market research for informational purposes and is strictly advisory. Actual prices are set by the independent technician. iHVAC is not a party to any transaction and assumes no liability, operating with zero middleman billing or liability.
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For the tech
What this work is actually worth
Undercharging is the chronic problem for independent and side-job techs — you quote the part plus a little, forget what it really costs to show up, and train customers to expect cheap. The ranges above aren't a ceiling. Here's how to think about pricing this job so you're not working for free.
Why it's worth it
A correct load calc, the right venting for a high-efficiency unit, permits, and a clean install that lasts 15–20 years is a craftsman's job. You're not selling a box — you're selling that it's sized and installed right.
Don't undercut yourself
Racing a private-equity shop to the bottom on a furnace install means cutting the load calc or the venting — exactly where the callbacks live. Price the work you actually do.
Build these into every price — not just the part:
Drive + windshield time. The hour each way isn't free. If you're not billing for getting there, you're working below your hourly.
Truck, tools, fuel. Your van, gauges, recovery machine — what they cost to own and run is overhead on every single call.
License, insurance, bond. Carrying real coverage is what separates you from the unlicensed guy. It has to be priced in, not eaten.
Callback & warranty risk. Some jobs come back. A price with zero margin for a return trip loses money on the ones that do.
Taxes & self-employment. As a 1099 independent you owe self-employment tax and your own withholding. The number you charge isn't the number you keep.
Your expertise isn't free. Knowing exactly what's wrong in five minutes is the product. An unskilled-labor rate undersells the one thing customers can't get elsewhere.
Help build the real number
The most accurate guide isn't built from national averages — it's built from what techs in your area actually charged. Contribute what you charged for this job and it feeds the local range here. It's opt-in, fully anonymized, and only ever shown as an aggregate once enough techs have contributed — never your individual price, never a price iHVAC sets, never a floor anyone has to hold. Just real market information, so the whole trade prices its work fairly.
Contribute what you chargedCommon questions
How long should a furnace last?
In a Midwest climate, a well-maintained gas furnace typically lasts 15–20 years. If yours is in that range and needs an expensive repair, replacement is worth pricing.
Is a high-efficiency (95%+) furnace worth it in Illinois?
In a cold, heating-heavy climate, the gas savings from a 95%+ furnace add up faster than in mild regions. The tradeoff is higher upfront cost and venting changes — a good tech runs the payback math with you.
Why do furnace quotes vary so much?
Efficiency tier, sizing, brand, venting work, and labor all move the number. That's exactly why this guide exists — so a $9,000 quote on a simple 80% swap stands out as worth questioning.
Related costs
How we research these numbers
This range is synthesized from published 2025–2026 US HVAC cost data and HVAC field knowledge, then regionalized toward northern Illinois. It's market reference — not a quote, and not a price iHVAC sets. As real techs complete jobs on iHVAC, these ranges will be backed by the actual local prices homeowners pay — the most accurate source there is.
References triangulated for this guide: