ComfortCostGuide

Metro cost guide

St. Louis, Missouri: HVAC Replacement Cost Calculator

Replacing HVAC equipment in St. Louis typically runs $4,000 to $7,500 for a central air conditioner and $3,500 to $7,000 for a gas furnace, installed. Homeowners swapping both at once — the most common project in older St. Louis housing stock — usually pay between $7,500 and $13,000. Local labor rates sit slightly below the national average, with HVAC technicians in the metro earning about $30.01 an hour.

Worked example

Take a 1,900-square-foot two-story home in south St. Louis with a 20-year-old gas furnace and a matched AC condenser that finally quit in July. Because the furnace is near the end of its life too, the owner replaces both as a matched system. With existing ductwork in usable shape and a straightforward basement install, this job lands near the middle of the local $7,500-$13,000 range for an AC-plus-furnace replacement — call it roughly $9,500 to $10,500 for mid-efficiency equipment. Adding a variable-speed blower, a high-SEER2 condenser, or significant duct repairs would push it toward the $13,000 end.

Frequently asked questions

How much does it cost to replace a furnace in St. Louis?

A gas furnace replacement in St. Louis generally costs $3,500 to $7,000 installed. Simple like-for-like swaps in homes with accessible basement equipment fall at the low end, while high-efficiency condensing furnaces that need new venting and a condensate drain push toward the top of the range.

Is a heat pump worth it in St. Louis, or should I stick with a gas furnace?

St. Louis sits in climate zone 4, where winters are cold enough that many homeowners keep gas heat as a backup rather than going all-electric. Heat pumps here run $6,000 to $12,000 installed versus $3,500 to $7,000 for a gas furnace, so the decision usually comes down to your electric and gas rates and whether you want one system handling both heating and cooling.

What does central air conditioning cost in St. Louis?

Expect $4,000 to $7,500 installed for central AC in the St. Louis area. Replacing just the condenser and coil on existing ductwork keeps you near the low end; higher-efficiency equipment, a larger tonnage for a big or poorly insulated home, or duct modifications move you higher.

Why do St. Louis quotes vary so much for the same job?

Labor in the St. Louis metro runs slightly under the national average — the local labor index is 0.96, with technicians earning about $30.01 per hour — but labor is only part of the bill. Equipment efficiency tier, whether your ductwork and electrical need work, and access to the furnace in older city homes with tight basements account for most of the spread within each range.

How much does a ductless mini split cost in St. Louis?

Ductless mini splits in St. Louis run $3,500 to $10,000 installed. A single indoor head for a converted attic, sunroom, or garage sits near the bottom of that range, while a multi-zone system covering several rooms of a home without ductwork lands at the top.

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