How Much Does a Furnace Cost Installed in North Shore IL? (2026 Ranges)
Gas furnace replacement costs in North Shore IL depend on efficiency rating, staging (single vs. two-stage vs. modulating), blower type, and any venting modifications required. The ranges below reflect complete installed cost in Lake and Cook County for 2026 — equipment, labor, permit, and haul-away — at Legendary's flat-rate pricing.
Bands for Lake and Cook County homes — not a quote. Every Legendary job is priced upfront flat-rate after we see the equipment and the home.
| Option | Typical range | Notes |
|---|---|---|
| 80% AFUE single-stage furnace (standard efficiency) | $2,800–$4,200 | Lowest upfront cost. Limited Nicor rebate eligibility. B-vent or existing chimney. Suitable for unconditioned spaces or budget replacement. |
| 96% AFUE two-stage furnace (high efficiency, PVC vent) | $3,800–$5,500 | Most popular North Shore replacement. Qualifies for Nicor Gas rebate (typically $100–$200). PVC venting required — cannot use existing B-vent chimney. |
| 96% AFUE variable-speed modulating furnace (premium efficiency) | $5,500–$7,500 | Quietest operation; best humidity control; lowest operating cost. Nicor rebate may apply. 12-year registered warranty on Daikin Comfort Pro / Design Pro models. |
| 80% AFUE two-stage furnace (mid-tier, B-vent compatible) | $3,200–$4,800 | Better comfort than single-stage without needing new venting. No Nicor rebate. Reasonable intermediate choice for B-vent homes not ready for full venting upgrade. |
What changes the price
- AFUE rating: 80% vs. 96% — 16 percentage points translates to $300–$600/year savings on Nicor bills for a North Shore home
- Venting type: 96% AFUE condensing furnaces require PVC or CPVC venting, not B-vent — factor in venting cost for homes without existing PVC
- Staging: modulating furnaces are quieter and more efficient but cost $1,000–$2,000 more than single-stage
- Home size: 80,000–100,000 BTU typical for North Shore single-family homes; larger homes (4,000+ sq ft) may need 120,000 BTU
- Permit: mechanical permit required in all North Shore municipalities; included in Legendary's flat-rate quotes
- Nicor Gas rebates for 96% AFUE models — reduces net cost
FAQs
- How long does a furnace last on the North Shore?
- High-quality gas furnaces last 18–25 years with annual maintenance. Older equipment without maintenance may fail earlier. Legendary recommends annual furnace tune-ups to maximize equipment life and maintain safety.
- Why does a 96% AFUE furnace require PVC venting?
- A 96% AFUE condensing furnace extracts so much heat from combustion gases that the exhaust is cool and acidic — too cool and corrosive for metal B-vent. PVC or CPVC pipe handles the low temperature and resists condensate corrosion. The PVC runs out through a side wall, not through the chimney.
- What is the Nicor Gas rebate for a furnace in 2026?
- Nicor Gas offers rebates for qualifying 96% AFUE furnaces, typically $100–$200 depending on the program year and equipment specs. Rebate amounts change annually. Legendary confirms eligibility and assists with rebate paperwork.
- Can I get a furnace replacement on a same-day schedule?
- Legendary schedules most furnace replacements with 1–5 business days lead time. Emergency or priority scheduling is available when a system has failed during heating season.
Editorial provenance
Content by Legendary Service editorial team
Updated:
Methodology
Published ranges are planning bands. The final scope depends on equipment, access, permits, code requirements, and conditions confirmed during an in-home diagnosis; Legendary Service then provides an upfront flat-rate price.
Comfort, handled — across the North Shore.
Tell us what's happening at your Lake County or Cook County home. You'll get upfront flat-rate pricing, a clear explanation before work begins, and the same above-code standard we'd want in our own homes.
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