How Much Does a Boiler Cost Installed in North Shore IL? (2026 Installed Ranges)
Boiler replacement costs in North Shore IL depend on boiler type (condensing vs. non-condensing), BTU output, number of zones, venting requirements, and whether zone valves, circulators, or expansion tank work is included. Ranges below reflect typical installed costs in Lake and Cook County for 2026 — at Legendary's flat-rate pricing, including permit, haul-away, and startup. The North Shore has a significant inventory of older cast-iron boilers in 1920s–1960s construction — these homes are strong candidates for efficiency upgrades.
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 |
|---|---|---|
| Non-condensing gas boiler replacement (80–84% AFUE, up to 3 zones) | $4,500–$7,500 | Compatible with existing B-vent or chimney flue. Lower upfront cost but higher operating cost than condensing. Suitable when new side-wall venting is not feasible. |
| Condensing gas boiler replacement (90–96% AFUE, up to 3 zones) | $6,000–$10,000 | PVC or polypropylene side-wall venting required — cannot use existing masonry chimney. 12–16% more efficient than non-condensing; pays back in 4–7 years at Nicor rates. OAR controls standard. |
| Condensing gas boiler + zone valve and circulator upgrade (3–5 zones) | $7,500–$13,000 | Includes replacement of aging zone valves and circulators. Most complete hydronic system upgrade. Improves comfort and reliability across all zones. |
| Boiler component repair (circulator pump, zone valve, expansion tank, aquastat) | $300–$1,200 | Flat-rate repair for isolated component failure. Right choice for systems under 18–20 years old. |
| Major boiler repair (heat exchanger, gas valve, primary controller) | $800–$2,500 | At this cost on a 20+ year boiler, replacement math often wins — especially given the efficiency upgrade available. |
What changes the price
- System age: under 15 years → component repair is likely appropriate; 20+ years with major failure → replacement conversation
- Condensing vs. non-condensing: 90–96% AFUE condensing boilers save $400–$900/year vs. 80% non-condensing on North Shore Nicor bills
- Venting: condensing boilers require PVC side-wall venting — cannot use existing chimney. Homes with chimney-only access may face venting routing challenges.
- Zone count: additional zone valves and circulators add cost but improve comfort and efficiency
- Outdoor air reset (OAR): all Legendary boiler replacements include OAR as standard — modulates water temperature with outdoor conditions for better efficiency
- Permit: mechanical permit required for all boiler replacements; included in Legendary's flat-rate quotes
- Nicor Gas rebates may apply for condensing boilers meeting minimum AFUE thresholds
FAQs
- How long do boilers last on the North Shore?
- Cast-iron non-condensing boilers often last 25–40 years with good maintenance — many North Shore homes have original boilers from the 1970s and 1980s still running. Condensing stainless steel boilers typically last 20–25 years. Annual service is essential to reach these lifespans.
- Why can't a condensing boiler use my existing chimney?
- Condensing boilers produce cool, acidic flue gases that corrode masonry and metal chimneys. The exhaust must be routed through PVC or polypropylene piping to a side-wall termination. The existing chimney is left intact and may be repurposed for a water heater vent if applicable.
- What is outdoor air reset (OAR) on a condensing boiler?
- OAR is a control strategy that modulates boiler water temperature based on outdoor temperature — hotter water on cold days, cooler water on mild days. It significantly improves condensing efficiency (the boiler condenses more heat at lower water temperatures) and eliminates the temperature overshoot that causes comfort complaints. OAR is standard on all Legendary boiler replacements.
- Does Legendary service and repair boilers it didn't install?
- Yes. Legendary services all major boiler brands — Navien, Weil-McLain, Buderus, Triangle Tube, Burnham, Peerless, and others — regardless of who installed them. All repairs are flat-rate priced.
- What is a Free Second Opinion for a boiler replacement?
- If you've received a recommendation to replace your boiler and want an independent assessment, Legendary will evaluate the boiler, identify the specific failure, and give you an honest opinion on repair vs. replacement — at no charge.
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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