What a furnace replacement costs on the North Shore.
A gas furnace replacement on Chicago's North Shore typically runs $4,500-$9,000 installed. An 80% AFUE unit in a straightforward swap sits at the bottom of that range; a 96-97% AFUE condensing furnace in a pre-war home that needs new venting, a chimney liner for the orphaned water heater, and return-air work sits at the top. Efficiency tier and what is behind the wall move the number far more than brand does.
Published 2026-08-31 · Last reviewed 2026-08-31 · Typical installed project totals for the Chicago North Shore, not quotes.
Cost by home size
Square footage drives capacity and capacity drives price. These are the same size adjustments the instant estimate calculator uses, so the two never disagree.
| Home size | Typical installed |
|---|---|
| Smaller homes (under 1,500 sq ft) | $3,800-$7,900 |
| Typical homes (1,500-2,500 sq ft) | $4,500-$9,000 |
| Larger homes (2,500-4,000+ sq ft) | $5,000-$11,900 |
What the range covers
- Equipment, and the labor to remove and haul away the old furnace
- Standard venting for the efficiency tier being installed
- Condensate drain and pump where a condensing furnace needs one
- Thermostat, standard electrical connection, and startup with combustion testing
- Warranty registration and the Nicor rebate paperwork
- Full ductwork replacement, as opposed to modifying the plenum and returns
- Asbestos abatement on old duct wrap or pipe insulation
- Electrical service or panel upgrades
- Structural work to reach a buried or boxed-in furnace
What actually moves the number
- Efficiency tier, and where the cliff actually is
- The jump that costs money is not 95% to 97%. It is 80% to 90%-plus. Anything above 90% AFUE is a condensing furnace, which produces acidic condensate and cannot vent up a masonry chimney. That single change brings new PVC venting, a condensate drain or pump, and often a chimney liner with it. Inside the condensing tier, moving from 95% to 97% is a modest equipment upgrade that earns the larger Nicor rebate.
- The orphaned water heater
- This is the line item most quotes do not explain and the most common reason two bids differ by four figures. In a lot of North Shore homes the furnace and the water heater share one masonry chimney. Take the furnace off it and the water heater is left venting alone into a flue sized for two appliances. It no longer drafts properly. Doing that correctly means lining the chimney down to the water heater's size, and doing it wrong is a combustion safety problem, not a comfort one.
- Return air, not supply
- Pre-war housing stock across Winnetka, Wilmette and Kenilworth was ducted for gravity furnaces and later adapted. Returns are frequently undersized for a modern high-static blower. A furnace starved for return air is loud, short-cycles, and never delivers its rated efficiency, so an honest quote on an older home often includes adding or enlarging a return.
- Blower type
- A single-stage furnace with a PSC blower is the cheapest thing that will heat the house. A two-stage or modulating furnace with a variable-speed ECM blower costs meaningfully more, runs longer at lower output, and is the difference most people actually notice day to day, especially in a house with a cold room upstairs.
- Gas supply
- A larger or higher-input furnace on an already-loaded gas line can require an upsize back toward the meter. This is found at the estimate by counting what else is on the line, not discovered on install day.
- Sizing, which is not a price driver so much as a price trap
- Capacity comes from a load calculation on the actual house, not from reading the plate on the old unit. Old furnaces were routinely oversized by half. Replacing an oversized furnace with an equally oversized one costs more up front and short-cycles for twenty years.
When repairing the furnace you have is the better buy
Under roughly ten years old, still under parts warranty, and a repair that is a small share of a new system: repair it. Past fifteen years, out of warranty, and facing a heat exchanger or control board, the repair usually just buys a season and then you make the purchase anyway with the repair bill already spent. The specific case where replacement wins early is a cracked heat exchanger, because that is a combustion safety condemn, not a cost decision. The specific case where repair wins late is a twenty-year-old furnace with a modest igniter fault in January, when the right move is to fix it, get through the season, and replace it in the spring at a better price and on your own schedule.
Furnace installation cost, and why it is the same number here
Furnace installation cost and furnace replacement cost return the same figure on almost every North Shore house, because almost every furnace put in here is replacing one that is coming out. The range above is an installed project total either way. The word installation only means something different in two situations. One is a house on boiler heat with no ductwork at all, where the duct system is the real project and the furnace is an accessory to it - that is a substantially larger number and it belongs next to a ductless comparison, not on this page. The other is new construction, where the furnace is designed into the plan rather than fitted into a mechanical room somebody already built around. If neither describes your house, stop comparing the words and start comparing what each bid includes for venting and the chimney, because that is where the money actually moves.
Nicor Gas pays roughly $225 on a 97% AFUE furnace and about $150 on 95% AFUE. The equipment has to be selected to hit the tier at quote time, because the rebate follows the model number and cannot be added to the paperwork afterward. Some North Shore towns are served by North Shore Gas rather than Nicor, where the equivalent program differs. The federal 25C tax credit is not available - it ended for equipment placed in service after December 31, 2025.
Current ComEd and Nicor rebatesMethodology
This range is the typical installed project total for furnace replacement across Chicago's North Shore - Evanston, Wilmette, Winnetka, Kenilworth, Glencoe, Highland Park, Lake Forest, Northbrook, Glenview and the surrounding communities. It reads from the same figures as the instant estimate calculator and the main cost reference, so there is one set of numbers on this site rather than three. Ranges are reviewed as equipment and utility program pricing move, and the last-reviewed date above is accurate rather than automatic.
Furnace Replacement cost questions
On Chicago's North Shore, $4,500-$9,000 installed is the normal range. An 80% AFUE furnace in a house whose venting does not have to change is at the low end. A 96-97% condensing furnace in an older home needing new venting, a chimney liner and return-air work reaches the top.
Usually one of three things, and it is worth asking which. Efficiency tier, because a condensing furnace drags venting work along with it. The chimney liner, because whoever accounted for the orphaned water heater looks more expensive and is the one quoting the job correctly. Or blower type, because a modulating furnace with a variable-speed blower is a different product from a single-stage unit at the same AFUE.
The equipment upgrade is small and it earns the larger Nicor rebate, which closes much of the gap. The honest framing is that both are condensing furnaces, so the expensive structural change - venting, condensate, liner - is already paid for at 95%. Going to 97% from there is one of the cheaper efficiency gains available. Going from 80% to 95% is where the real money and the real savings both are.
Only if the AC is near its own end of life. The install labor genuinely overlaps, and a matched system replaced together runs $9,000-$18,000 rather than two separate projects. But replacing a healthy eight-year-old condenser to save on labor is spending several thousand dollars to avoid a few hundred.
A straight swap is a single day. Add a chimney liner, new venting, or return-air modifications and it commonly runs into a second day. Anything quoted as a two-hour job on an older North Shore home is not accounting for the venting.
No. They are planning ranges for Chicago's North Shore. A real price needs a load calculation and an in-home look at the venting, the chimney, the returns and the gas line. The written estimate is the number that counts.
The same as furnace replacement on a house that already has a furnace: $4,500-$9,000 installed on Chicago's North Shore. Installation becomes a different and larger number only where there is no ductwork to install into, as in a boiler-heated house being converted, or in new construction. For a normal changeout, an 80% AFUE unit with unchanged venting is the low end and a 96-97% condensing furnace needing new venting, a chimney liner and return-air work is the top.
“Furnace Replacement Cost on the North Shore (2026): $4,500-$9,000 Installed,” North Shore HVAC Replacement, last reviewed 2026-08-31. https://northshorehvacreplacement.com/costs/furnace-replacement/
Other system costs
The instant estimate calculator gives you a range for your house in about a minute, and it shows the number before it asks for your contact information. $4,500-$9,000 is the planning range; your house has one number inside it.