HVAC Replacement in Knollwood, Illinois.
HVAC replacement in Knollwood typically runs $4,500-$18,000 installed in 2026 - furnace-only changeouts start around $4,500-$9,000, while full furnace-plus-AC systems run $9,000-$18,000, before utility rebates.
Knollwood is a small unincorporated Lake County community of postwar ranch homes. Furnace-and-AC changeouts, plus the duct problems that come with crawl-space distribution, are the core of local demand.
Replacement services in Knollwood
High-efficiency gas furnace replacement for North Shore and NW suburban homes.
Central air conditioner replacement sized right for comfort and efficiency.
Furnace and AC replaced together as one matched, high-efficiency system.
Hot-water and steam boiler replacement for older North Shore housing stock.
Cold-climate electric heat pumps that qualify for tiered utility rebates.
Ductless heating and cooling for additions, attics, and homes without ductwork.
On-demand tankless water heaters for endless hot water and less wasted space.
24/7 response when the heat or AC dies and can't wait for a scheduled visit.
Repairs and maintenance plans
Not ready to replace? Each service has its own page with what a visit covers and what it costs.
Systems common in Knollwood
Knollwood's housing stock shapes the kind of work we do. We regularly service and replace Postwar ranch forced-air systems, Original single-zone ductwork, Crawl-space furnaces, High-efficiency furnaces, Heat pumps across this area. Each calls for a different approach - boilers and steam systems differ from forced-air furnaces, and older homes often need careful venting and duct work.
Why Knollwood homes plan replacements early
Knollwood is unincorporated Lake County, a small pocket of postwar ranches and split-levels between Lake Bluff and Libertyville. The houses are modest and mostly single-story, which sounds simple until you look at the ductwork: much of it is original, single-zone, and run through crawl spaces where the insulation has sagged or disappeared. A furnace replaced without addressing that duct loss will underperform its rating no matter what the label says. Several of these properties are also on well and septic, so anything involving a condensate line or a heat pump needs the site looked at rather than assumed.
Talk it through - (847) 752-4418Neighborhoods we serve in Knollwood
Local crews familiar with the area. Recent work across:
Around Knollwood
We work homes throughout Knollwood, including areas near Knollwood Club, Des Plaines River Trail, Rockland Road, Lake Bluff border. Whether it's a single-family home, a townhome, or an HOA-managed property, we bring the same local knowledge to every project.
Typical installed costs in Knollwood (2026)
| Furnace Replacement in Knollwood | $4,500-$9,000 |
| AC Replacement in Knollwood | $4,000-$8,000 |
| Full System Replacement in Knollwood | $9,000-$18,000 |
| Boiler Replacement | $7,000-$15,000 |
| Heat Pump Installation | $10,000-$22,000 |
| Ductless Mini-Split Installation | $4,000-$14,000 |
| Tankless Water Heater Installation | $3,500-$6,500 |
| Emergency HVAC Replacement | $4,500-$18,000 |
Rebates in Knollwood
High-efficiency systems installed in Knollwood often qualify for Nicor Gas and ComEd rebates, and heat pumps can earn tiered ComEd rebates. We size and select equipment to hit rebate thresholds and hand off the paperwork you need to claim them.
Frequently asked - Knollwood
Do you serve all of Knollwood?
Yes. We cover every neighborhood in Knollwood, including Knollwood, Lake Bluff border, Rockland Road corridor, Route 176 area and surrounding areas.
What does a new system cost in Knollwood?
Most Knollwood replacements run $4,500-$18,000 depending on whether it's a furnace, AC, full system, or boiler, plus efficiency and home configuration. You get a written, itemized estimate from a free in-home visit - with ComEd and Nicor rebates factored in.
Are you available 24/7 for emergencies in Knollwood?
Yes. We run a 24/7 line for no-heat and no-cool emergencies in Knollwood and can prioritize an emergency replacement.
How much does a new furnace or AC cost on the North Shore?
Installed furnace replacements typically run $4,500-$9,000, central AC $5,000-$10,000, and a full furnace-plus-AC system $9,000-$18,000. Boilers (common in older North Shore homes) run $7,000-$15,000, and heat pumps $10,000-$22,000 before rebates. Final pricing depends on system size, efficiency, and how your home is configured. Every quote is written and itemized after an in-home estimate.
Should I repair or replace my system?
As a rule of thumb, if a system is 15+ years old, needs a repair that costs more than about a third of a new unit, or has failed more than once in a season, replacement usually saves money over time. We give an honest recommendation - if a repair makes more sense, we'll say so, and we'll do the repair.
Do you do repairs, or only replacements?
Both. We repair furnaces, air conditioners, and boilers, with a $99-$169 diagnostic that is credited toward the repair and a flat repair price you approve in writing before any work starts. Most repairs run $180-$950 depending on the equipment and the fault. Replacement is what we specialize in, but that does not mean we push it - a good system with a failed part gets the part.
Do you offer a maintenance plan or service agreement?
Yes. Plans run $199-$399 per year depending on tier and how many systems the home has, and cover two seasonal visits - heating in the fall, cooling in the spring - plus priority dispatch and a discounted repair rate for members. A one-off tune-up without a plan is $129-$199. Most manufacturer warranties require documented annual maintenance, so a plan also keeps that coverage intact.