How much does hvac replacement cost in St. Louis, MO?

Most St. Louis homeowners spend between $5,150 – $16,900 on hvac replacement, with an average around $8,650. Local labor prices 6% below the national average, so St. Louis quotes tend to land at the lower end of national ranges.

Why is hvac replacement more or less expensive in St. Louis than elsewhere?

Licensed trade labor in St. Louis runs about 94% of the national average, and the best crews book out fastest in spring and early summer. Missouri weather drives material choices here, so ask contractors what they install most often in St. Louis and why.

Do I need a permit for hvac replacement in St. Louis, Missouri?

Most St. Louis, MO projects that change structure, electrical, plumbing or mechanical systems need a permit from the local building department; cosmetic work usually does not. Always confirm current requirements with the local building department before signing a contract, and make sure the permit is pulled by your licensed contractor.

How many quotes should I get in St. Louis?

Get at least three written quotes from licensed, insured Missouri contractors. Comparing line items — not just the bottom line — is the fastest way to spot an inflated bid in the St. Louis metro market.

How much does it cost to replace an HVAC system?

$5,500 to $18,000 installed, averaging about $9,200 for a complete system in a typical single-family home.

How long does an HVAC system last?

Central AC and heat pumps last 12–17 years, gas furnaces 15–25 years. Replace rather than repair once you cross about 75% of that life.

What size system do I need?

Roughly one ton per 500–600 square feet as a starting point, but insist on a Manual J calculation — climate, insulation and windows change the answer.

Is a heat pump cheaper than a furnace?

A heat pump costs more upfront but usually cuts total energy bills where electricity is reasonably priced, and it qualifies for a larger tax credit.

How long does installation take?

One day for a straight equipment swap; two to four days if the ductwork or electrical service is being replaced.

Home/Cost guides/HVAC Replacement/St. Louis, MO

St. Louis metro · Missouri

HVAC Replacement cost in St. Louis, MO

St. Louis homeowners typically pay $5,150 – $16,900 for hvac replacement. Local labor and materials price 6% below the national average.

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St. Louis average

$8,650

Typical low

$5,150

Typical high

$16,900

Per ton of cooling capacity

$1,700 – $2,650

Sample ZIP

What drives St. Louis pricing

Local labor

Licensed trade labor in St. Louis runs about 94% of the national average, and the best crews book out fastest in spring and early summer.

Permits & code

Most St. Louis, MO projects that change structure, electrical, plumbing or mechanical systems need a permit from the local building department; cosmetic work usually does not.

Climate & conditions

Missouri weather drives material choices here, so ask contractors what they install most often in St. Louis and why.

Instant cost calculator

Adjust the inputs to see live pricing

System size3 tons

System type

Efficiency

Ductwork

Equipment location

Estimated project cost

$3,900 – $7,350

Most homeowners pay around $5,625

Compare system type

Cost by material in St. Louis

Installed St. Louis pricing per ton of cooling capacity.

Option	Installed cost	Pros	Cons
Central air conditioner	$3,750 – $8,450	Lowest cost cooling upgrade if ducts exist.	Needs a separate heat source.
Gas furnace	$3,300 – $7,050	Cheapest heat in cold climates with cheap gas.	Requires venting and combustion safety checks.
Heat pump	$5,150 – $11,300	Heats and cools; often qualifies for tax credits up to $2,000.	Needs backup heat in very cold climates.
Ductless mini-split	$2,800 – $9,400	No ducts needed, zone by zone control.	Indoor heads are visible on the wall.
Geothermal	$16,900 – $42,300	Lowest operating cost and 25+ year life.	Requires drilling or a large loop field.

Where the money goes in St. Louis

A typical $8,650 St. Louis project, broken down by line item.

Equipment50% · $4,325
Labor & installation30% · $2,595
Ductwork & line set13% · $1,125
Permit, startup & disposal7% · $606

Common add-ons

Extras that show up on St. Louis quotes but rarely in the headline price.

Full duct replacement

$1,900 – $5,650

Duct sealing & insulation

$660 – $2,350

Smart thermostat

$170 – $565

Whole-home air purifier

$565 – $2,350

Whole-home humidifier

$375 – $1,150

Electrical panel upgrade for heat pump

$1,400 – $3,750

Permit & inspection

$94 – $470

Ways to save in St. Louis

Replace in spring or fall — mid-summer emergency swaps carry a 10–20% premium.
Claim the 25C federal tax credit: up to $2,000 for a qualifying heat pump, $600 for AC or furnace.
Check your utility's rebate portal; many add $500–$1,500 on high-efficiency equipment.
Right-size with a Manual J load calculation — oversized systems cost more and short-cycle.
Don't over-buy SEER in mild climates; the payback can exceed the equipment's life.

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