Full HVAC System Replacement Cost
Typical market range as of May 2026 · regionalized for northern Illinois
Most homeowners
$12,500
Replacing a full HVAC system — furnace and central AC together — typically runs $8,000–$20,000 installed, with a national average near $12,500. Doing both at once saves on labor versus two separate visits, but the number climbs fast with efficiency tier, home size, and any ductwork that needs replacing (a full duct replacement alone adds roughly $2,000–$4,000).
Pricing this job, not hiring for it? See what the work is worth →What drives the price
Doing both at once
Replacing furnace and AC together shares labor and a single permit/inspection — cheaper than two separate projects.
Ductwork
Old, leaky, or undersized ducts may need repair or replacement — a full duct job adds ~$2,000–$4,000.
Efficiency tiers
A basic matched system vs. a high-AFUE / high-SEER2 pairing is the difference between the low and high ends.
Rebates & tax credits
High-efficiency equipment and heat pumps may qualify for federal tax credits and utility rebates that cut the net cost.
In our market — McHenry County & northern Illinois
In McHenry County, a full furnace-plus-AC replacement commonly lands $10,000–$16,000 depending on efficiency and ductwork. Because northern Illinois is heating-dominated, prioritize furnace sizing and AFUE; pair it with a correctly sized mid-SEER2 AC rather than over-buying cooling efficiency you'll only use a few months a year. Bundling both replacements in one project is the single biggest labor saving available.
Walk in informed
Get itemized, written quotes from at least two or three techs — equipment, labor, ductwork, permits, and rebates broken out separately. On a five-figure project, a vague lump sum or a 'sign today' discount is a reason to pause, not rush.
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.
Not sure this is your problem yet?
Talk to Dale — iHVAC's free AI diagnostic. He'll narrow down what's actually wrong before you call anyone, so you know exactly which job you're looking at. No signup, no catch.
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 full furnace-plus-AC changeout is a multi-day, five-figure project with permits, ductwork judgment, and a system that has to be commissioned as a matched whole. This is your highest-value work.
Don't undercut yourself
Five-figure projects are where underpricing hurts most. Itemize equipment, labor, ductwork, and permits so the customer sees the value — and so you're not absorbing scope you quoted away.
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
Should I replace the furnace and AC at the same time?
If both are old (12–15+ years), usually yes — you share labor, permitting, and a matched-system warranty, and you avoid pairing new and old components. If only one is failing and the other is young, replace just the one.
Does ductwork need replacing too?
Not always — but leaky, undersized, or damaged ducts undercut a brand-new system. A good tech inspects the ducts and tells you honestly whether they're fine, need sealing, or need replacement.
Are there rebates or tax credits?
Often. High-efficiency systems and heat pumps can qualify for federal tax credits (up to $2,000/yr for qualifying heat pumps under current law) plus utility rebates. Ask your tech and check your utility's program before you buy.
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: