ComfortCostGuide

State cost guide

Illinois: HVAC Replacement Cost Calculator

Most Illinois homeowners replacing both sides of their system pay between $7,500 and $13,000 installed for a matched gas furnace and central air conditioner. Standalone jobs cost less: $3,500 to $7,000 for a gas furnace and $4,000 to $7,500 for central AC. Illinois labor runs about 20% above the national baseline, with HVAC technicians earning an average of $37.29 per hour, so installation is a meaningful share of every quote.

Worked example

Take a 1,900-square-foot two-story home outside Chicago with a 21-year-old gas furnace and an AC condenser of the same age. Because the ductwork is intact and the equipment sits in an accessible basement, a mid-efficiency furnace paired with a new condenser and coil would land near the middle of the $7,500-$13,000 range for a combined replacement. Push toward the top of that range if you add a high-efficiency variable-speed furnace, need a new flue liner, or the install requires electrical and condensate work to bring the setup up to code.

Frequently asked questions

How much does it cost to replace a furnace and AC together in Illinois?

Replacing both at once typically runs $7,500 to $13,000 installed in Illinois. Doing them together usually costs less than two separate jobs a few years apart, since the crew makes one trip and the furnace blower and AC coil are matched from the start.

Does a heat pump make sense in Illinois's cold winters?

Illinois sits in climate zone 5, so winters are cold enough that most homes pair a heat pump with backup heat rather than running it alone. Installed costs range from $6,000 to $12,000, and the higher end generally reflects cold-climate models or dual-fuel setups that switch to a gas furnace when temperatures drop.

Why are HVAC installation quotes higher in Illinois than the national average?

Labor in Illinois runs roughly 20% above the national baseline, with HVAC technicians averaging $37.29 per hour. Since a full changeout takes a two-person crew most of a day or longer, that wage difference shows up directly in your bid, especially on jobs with venting or ductwork changes.

What does a ductless mini split cost in Illinois?

Ductless mini splits run $3,500 to $10,000 installed in Illinois. A single indoor head serving one room or an addition sits near the bottom of that range, while a multi-zone system covering several rooms pushes toward the top.

Is it cheaper to replace just the furnace in Illinois?

Yes. A gas furnace alone costs $3,500 to $7,000 installed, compared with $7,500 to $13,000 for a furnace and AC together. If your AC is under about 10 years old and still working well, replacing only the furnace is often the practical choice.

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