Winnetka HVAC Replacement Guide (2026)

Winnetka has some of the oldest and most valuable housing stock on the North Shore, and that shapes every heating and cooling decision here. From the historic homes of East Winnetka and Hubbard Woods to the estates near Indian Hill, much of the village was built long before central air was standard, and a great deal of it still runs on heating systems converted from their original coal or oil setups. Replacing HVAC in a home like this is not a routine suburban swap. It rewards experience with older houses, and it helps to understand what you are dealing with before you gather quotes.

Why Winnetka is different

The defining feature of Winnetka's housing is age and quality. Many homes were built with boilers and radiators rather than ducts, and even those that added forced-air heating later often did so as a retrofit into a house never designed for it. That has two consequences: the mechanical systems are frequently decades past their prime, and there is often no easy path for conventional ductwork. Getting comfort into these homes without tearing up plaster and finished walls is a real craft.

Because of that, the work here spans the full range: boiler replacement and modernization in radiator homes, careful furnace-and-AC changeouts in homes that were retrofitted, and space-conscious cooling solutions where there is simply no room for standard ducts.

Know what you have first

Before you get quotes, figure out how your home is heated, because it drives everything downstream:

• Hot-water or steam boilers heat through radiators and have no ductwork. Replacement is its own discipline, involving correct boiler sizing, near-boiler piping, and careful venting, especially in finished basements.
• Retrofitted forced-air systems use ducts added after the fact, which may be undersized or awkwardly routed. A proper load calculation matters here, since copying the old equipment's size often perpetuates a mistake.

A contractor who mostly does new suburban construction may not be the right fit for a century-old Winnetka home. Sizing and craftsmanship matter more than speed.

Cooling a home with no ductwork

The most common Winnetka summer question is how to get air conditioning into a radiator-heated home. Tearing ducts into finished historic walls is invasive and expensive, and it often is not worth it. Two approaches solve this without that disruption:

• Ductless mini-splits. A ductless system uses an outdoor unit and compact indoor heads connected by a small line set, so it needs no ducts at all. It delivers real cooling room by room and can add heat in the shoulder seasons. For radiator homes, keeping the boiler for winter and adding ductless for summer is one of the most sensible combinations available. Our ductless mini-split guide covers where it shines and its honest limits, including the visible indoor head.
• High-velocity systems use small flexible tubing that snakes through existing wall cavities, a good fit for some historic homes where a homeowner wants cooling without visible indoor heads.

An installer who knows Winnetka homes can tell you honestly which approach fits your house.

What it costs

Winnetka's older, larger homes tend to add labor, and the numbers vary widely by system type. As planning ranges on the North Shore:

• Boiler replacement typically runs $7,000 to $15,000, depending on steam versus hot water, standard versus condensing, and the condition of your piping and venting.
• Furnace replacement generally lands $4,500 to $9,000, and a matched furnace-and-AC full system $9,000 to $18,000.
• Ductless mini-split systems run $4,000 to $14,000 depending on how many zones you need.

These are starting points, not quotes. In a home as individual as a Winnetka house, the only accurate figure comes from a written, in-home estimate where an installer sees your actual system.

Rebates worth checking

Efficiency incentives can offset part of the cost, and they are worth confirming before you buy:

• Nicor Gas offers roughly $225 for a qualifying 97% AFUE furnace and up to about $500 for a qualifying combi boiler, with a smart thermostat rebate up to about $100.
• ComEd offers a tonnage-tiered rebate in the $1,400 to $2,000 range for qualifying cold-climate heat pumps, which is worth knowing if you go the ductless route.

Amounts and eligibility change, and some parts of the North Shore are served by North Shore Gas rather than Nicor, so verify the current programs. Our ComEd and Nicor rebates guide walks through what qualifies.

Timing it right

The best time to replace heating equipment is before you need it. The shoulder seasons, late spring through early fall, mean easier scheduling and room to compare written options without racing a cold snap. An aging boiler that limps through one more winter is a gamble, and a mid-January failure in a radiator home is both uncomfortable and slow to solve in a hurry.

Putting it together

If you own an older home in Winnetka, an HVAC replacement is a chance to make a few good decisions at once: confirm how your home is heated, size the new system to your actual house rather than the old one, and finally solve summer comfort with ductless or high-velocity cooling if you have been living without it. Do it with a licensed, insured installer who understands historic homes.

Learn more about typical local work on our Winnetka page, and if you are weighing whether to stay with a boiler at all, boiler versus forced air in older North Shore homes is a good next read.

When you are ready to plan it for your specific home, get a written free estimate or call (847) 752-4418.