Full System Replacement in Knollwood, Illinois
Full System Replacement in Knollwood typically costs $9,000-$18,000 installed in 2026, depending on home size and efficiency tier.
Knollwood houses tend to have been built with a matched furnace and condenser and to have stayed that way, which means when one goes the other is usually the same age and close behind. Replacing both together is generally the cheaper path here, not the more expensive one.
| Smaller homes (under 1,500 sq ft) | $7,700-$15,800 |
| Typical homes (1,500-2,500 sq ft) | $9,000-$18,000 |
| Larger homes (2,500-4,000+ sq ft) | $10,100-$23,800 |
Final pricing depends on system size, efficiency, and home configuration. Every quote is written and itemized after a free in-home estimate, with available utility rebates factored in. See current North Shore rebates or get an instant ballpark estimate.
Full System Replacement for Knollwood homes
The reason is mechanical, not sales. A new high-efficiency condenser paired with a decade-old indoor coil performs below both units' ratings, because the pair was never engineered to work together - you buy the efficiency and do not get to use it. Doing the furnace and the AC as one matched system in a single visit means one crew, one set of duct connections, one commissioning, and equipment that actually reaches the numbers on the label. It also stacks the Nicor and ComEd rebates in the same year rather than splitting them across two.
In a Knollwood ranch a full-system project is also the right moment to fix the crawl-space ductwork, because the runs are accessible exactly once while the equipment is out. We quote sealing and re-insulation as part of the job rather than as a surprise, size to a load calculation on the house as it stands, and plan condensate routing around well and septic where that applies. Written, itemized estimate from a free in-home visit before anything is ordered.
When Knollwood homeowners call us for this
- System is 15+ years old or out of warranty
- A repair would cost a large share of a new unit
- Rising energy bills or uneven comfort
- Repeated breakdowns in a single season
- Phased-out refrigerant (older R-22 AC)
- Planning ahead before a full failure
Why Knollwood homes need replacement planning
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 cover in Knollwood
Our process
- 1Free in-home estimate
A comfort specialist comes to your Knollwood home, measures the space, checks ductwork and venting, and explains options and honest price ranges in writing - no charge, no pressure.
- 2Right-sized equipment
We size the system with a proper load calculation and choose efficiency levels that qualify for the utility rebates you're eligible for.
- 3Professional installation
Licensed, insured installers remove the old system and install the new one to spec.
- 4Rebates, registration & follow-up
We register the warranty, hand off the utility rebate paperwork, and confirm everything is running right.
Frequently asked - Full System Replacement in Knollwood
How much does full system replacement cost in Knollwood?
Full System Replacement in Knollwood typically runs $9,000-$18,000 installed, depending on system size, efficiency, and how the home is configured. We provide a written, itemized estimate from a free in-home visit for every Knollwood project - and factor in the utility rebates you qualify for.
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.
Are you available 24/7 for emergencies in Knollwood?
Yes. We run a 24/7 line across Knollwood for no-heat and no-cool emergencies and can prioritize dispatch.
What kinds of systems do you commonly replace in Knollwood?
In Knollwood we regularly work with Postwar ranch forced-air systems, Original single-zone ductwork, Crawl-space furnaces, High-efficiency furnaces, Heat pumps. We match the approach to the home's age, ductwork, and venting.
Full System Replacement guides
Looking for the full picture on Full System Replacement or everything we do in Knollwood? Explore those pages, or call (847) 752-4418 for a free estimate today.