How Much Does Furnace and AC Installation Cost in Missouri in 2026
How Much Does Furnace and AC Installation Cost in Missouri in 2026?
A full HVAC system replacement in Missouri — furnace plus central air conditioner — averages $8,800 in 2026. That breaks down to roughly $3,000-$5,500 for a furnace and $4,000-$7,000 for a central AC unit, including installation labor. Heat pumps, which handle both heating and cooling, run $5,000-$9,000 installed and are gaining ground in Missouri thanks to improved cold-weather performance and utility rebates from Ameren and Evergy.
Missouri’s climate demands both systems work hard. Summer temperatures regularly hit 95-100F with high humidity in the St. Louis metro and river valleys, while winter lows drop to single digits across the northern half of the state. A failed furnace in January or a dead AC in July isn’t just uncomfortable — it’s a health risk. That urgency is why emergency HVAC replacements cost 20-30% more than planned installations.
This guide covers actual 2026 pricing by equipment type and city, available rebates, and how to avoid overpaying. If you’re buying a home and want to factor HVAC costs into your budget, the affordability calculator helps you see the full picture. Check out our Missouri HVAC company rankings.
Furnace Installation Costs in Missouri
Natural gas furnaces dominate Missouri’s heating market. Over 60% of Missouri homes use natural gas for heating, with propane common in rural areas and electric furnaces in some newer construction. Here’s what each type costs installed in 2026:
| Furnace Type | Equipment Cost | Installation Cost | Total Installed | Annual Operating Cost |
|---|---|---|---|---|
| Gas Furnace (80% AFUE) | $1,200 – $2,000 | $1,500 – $2,500 | $3,000 – $4,000 | $600 – $900 |
| Gas Furnace (95-96% AFUE) | $1,800 – $3,000 | $1,800 – $3,000 | $3,500 – $5,500 | $400 – $650 |
| Gas Furnace (98% AFUE) | $2,500 – $3,500 | $2,000 – $3,000 | $4,500 – $6,500 | $350 – $550 |
| Propane Furnace (95% AFUE) | $2,000 – $3,200 | $1,800 – $2,800 | $3,800 – $5,800 | $800 – $1,400 |
| Electric Furnace | $800 – $1,500 | $1,000 – $1,800 | $1,800 – $3,000 | $1,200 – $2,000 |
AFUE (Annual Fuel Utilization Efficiency) measures how much of the fuel becomes heat. An 80% AFUE furnace sends 20 cents of every dollar up the flue. A 96% AFUE unit loses only 4 cents. In Missouri, where heating season runs November through March, the $150-$350 annual savings from a high-efficiency furnace adds up over its 15-20 year lifespan.
One important note for Missouri: an 80% AFUE furnace uses a standard metal flue that vents through the roof. A 90%+ AFUE furnace uses PVC pipe vented through a sidewall. If you’re upgrading from 80% to 90%+, the installer must add PVC venting and may need to line or abandon the existing chimney flue — add $300-$800 for that work.
Air Conditioner Installation Costs in Missouri
Central air conditioning is essentially mandatory in Missouri. The STL metro regularly sees heat indices above 105F in July and August. Here’s what a new central AC unit costs installed:
| AC Size (Tons) | Typical Home Size | Equipment Cost | Total Installed |
|---|---|---|---|
| 2.0 tons | 1,000 – 1,300 sq ft | $1,800 – $2,800 | $4,000 – $5,200 |
| 2.5 tons | 1,300 – 1,600 sq ft | $2,000 – $3,200 | $4,500 – $5,800 |
| 3.0 tons | 1,600 – 2,000 sq ft | $2,400 – $3,800 | $5,000 – $6,500 |
| 3.5 tons | 2,000 – 2,400 sq ft | $2,800 – $4,200 | $5,500 – $7,000 |
| 4.0 tons | 2,400 – 2,800 sq ft | $3,200 – $4,800 | $6,000 – $7,500 |
| 5.0 tons | 2,800 – 3,500 sq ft | $3,800 – $5,500 | $6,500 – $8,500 |
SEER2 ratings matter for operating costs. The federal minimum as of 2023 is 14.3 SEER2 for Missouri (North region). Higher SEER2 ratings mean lower electric bills. An 18 SEER2 unit costs $1,500-$2,500 more than a 14.3 SEER2 unit but uses about 20% less electricity. On a $200/month summer electric bill, that’s $40/month in cooling savings — roughly $240 per cooling season in Missouri (May-September).
Heat Pump Costs in Missouri
Heat pumps are the fastest-growing HVAC segment in Missouri. Modern cold-climate heat pumps work efficiently down to 5F — well below Missouri’s typical winter lows in most of the state. A heat pump replaces both the furnace and AC with a single outdoor unit, though most Missouri installations keep a gas furnace as backup (called a “dual fuel” system).
Air-source heat pump (installed): $5,000 – $9,000
Dual fuel system (heat pump + gas furnace backup): $7,000 – $12,000
Mini-split heat pump (single zone): $3,000 – $5,000
Mini-split heat pump (multi-zone, 3-4 heads): $8,000 – $15,000
The federal 25C tax credit covers 30% of heat pump costs up to $2,000 in 2026. Combined with Ameren or Evergy rebates (see below), a heat pump can end up costing less out of pocket than a traditional furnace/AC combo.
Utility Rebates Available in Missouri
Missouri’s two major electric utilities offer rebates that can significantly reduce HVAC costs:
Ameren Missouri (serves STL metro, central and eastern MO):
- Air-source heat pump: $500 – $1,500 depending on efficiency
- High-efficiency central AC (16+ SEER2): $200 – $400
- High-efficiency gas furnace (95%+ AFUE): $200 – $300
- Smart thermostat: $50 – $75
- Ductwork sealing: $200 – $400
Evergy (serves KC metro, western MO):
- Air-source heat pump: $400 – $1,200 depending on efficiency
- High-efficiency central AC: $150 – $350
- Duct sealing and insulation: $200 – $500
- Smart thermostat: $50 – $100
Spire (Missouri’s natural gas utility) also offers rebates for high-efficiency gas furnaces, typically $200-$400 for units rated 95%+ AFUE. These rebates stack with the federal tax credit, so a heat pump installation could qualify for $2,000 (federal) + $1,500 (Ameren) = $3,500 in combined savings.
HVAC Costs by Missouri City
Labor rates and cost of living affect HVAC installation prices across the state. Kansas City and St. Louis command the highest rates, while rural areas and smaller cities run 10-20% lower.
Kansas City metro: $9,000 – $11,500 for a furnace/AC combo. High demand due to extreme temperature swings. The KC metro sees some of the coldest winter nights and hottest summer days in the state, pushing sizing requirements higher.
St. Louis metro: $9,200 – $12,000 for a furnace/AC combo. The STL metro’s humidity adds to cooling loads. Many older homes in the city have ductwork that needs modification or replacement — add $2,000-$5,000 for duct replacement. The age of STL’s housing stock (many pre-1950 homes) means more complex installations.
Springfield: $7,500 – $10,000 for a furnace/AC combo. Lower labor rates and a slightly milder climate reduce costs. The Ozarks elevation keeps summer highs a few degrees below STL and KC.
Columbia: $8,000 – $10,500 for a furnace/AC combo. College town with moderate pricing. Good contractor availability.
Independence/Lee’s Summit: $8,500 – $11,000 for a furnace/AC combo. Similar to KC metro pricing but slightly lower due to suburban competition.
Factors That Increase HVAC Installation Costs
Ductwork Modifications
If your existing ductwork is undersized, damaged, or poorly sealed, the new system won’t perform to its rated efficiency. Ductwork modifications cost $1,000-$3,000, and a full duct replacement runs $2,000-$5,000 for an average Missouri home. Homes built before 1970 often have ducts that are too small for modern high-efficiency systems. Getting a Manual J load calculation (about $150-$300) before buying ensures the system is properly sized for your specific home.
Electrical Upgrades
Some older Missouri homes have 100-amp electrical panels that can’t support a modern heat pump or high-efficiency AC. A panel upgrade to 200 amps costs $1,500-$2,500 and may be required before a heat pump installation. If your home was built before 1980, ask the HVAC contractor about electrical requirements early in the quoting process.
Zoning Systems
A zoned HVAC system uses dampers in the ductwork to control temperatures independently in different areas of the house. This is common in two-story Missouri homes where the upstairs runs 5-10 degrees warmer than the main floor in summer. Adding a two-zone system to a new installation costs $1,500-$3,000. It reduces energy waste by not heating or cooling empty rooms.
Refrigerant Transition
The industry is transitioning from R-410A to R-454B refrigerant. Equipment using R-454B is becoming standard in 2026. If your existing AC uses R-22 (common in units installed before 2010), you cannot simply recharge it — R-22 production has ended and remaining stock costs $100-$200 per pound. Replacement is the only cost-effective option.
How to Save on HVAC Installation in Missouri
Time your purchase. HVAC contractors are slowest in early spring (March-April) and late fall (October-November). Avoid emergency summer and winter replacements where you have no negotiating power.
Get three quotes minimum. HVAC pricing varies 25-40% between contractors for identical equipment. Make sure each quote specifies the exact model numbers, not just brand and tonnage.
Stack rebates and tax credits. A Missouri heat pump buyer can potentially combine a $2,000 federal tax credit, $500-$1,500 utility rebate, and $200-$400 gas utility rebate. That’s up to $3,900 off the installed price.
Consider a dual fuel system. In Missouri’s climate, a heat pump with gas furnace backup gives you the efficiency of a heat pump in moderate weather (fall, spring, mild winter days) and the reliable heat output of gas during the coldest nights. This setup costs $7,000-$12,000 but offers the lowest combined annual heating and cooling costs for most Missouri homes.
Don’t oversize. An oversized AC cools the house quickly but doesn’t run long enough to dehumidify — a major problem in Missouri’s humid summers. An oversized furnace short-cycles, wasting energy and wearing out components faster. A proper Manual J load calculation ensures the right size. If a contractor quotes you without doing a load calculation, get a different contractor.
If you’re budgeting for a home purchase and want to see how HVAC costs fit into your overall financial picture, the mortgage calculator can help you model different down payment and monthly expense scenarios.
HVAC Maintenance Costs in Missouri
Annual maintenance extends equipment life and prevents breakdowns. Missouri’s climate means both systems work hard, making maintenance especially important:
Annual tune-up (one system): $80 – $150
Annual tune-up (both furnace and AC): $150 – $250
Maintenance plan/contract: $150 – $300/year (includes two tune-ups, priority scheduling, and sometimes a parts discount)
Spring AC maintenance should happen in March or April before cooling season starts. Fall furnace maintenance should happen in September or October. Waiting until the first hot day or cold night to call means you’ll pay emergency rates and wait days or weeks for service. The maintenance calculator can help you project annual maintenance costs for all your home systems.
When to Repair vs. Replace
The general rule: if a repair costs more than 50% of a new system’s price, replace. Other replacement triggers:
Furnace: Replace if it’s over 20 years old, has a cracked heat exchanger (safety hazard, repair cost often exceeds $2,000), or requires frequent repairs (3+ service calls per year).
AC: Replace if it’s over 15 years old, uses R-22 refrigerant, has a failing compressor (repair cost $1,500-$2,500), or can’t maintain set temperature during peak summer heat.
Both: If your furnace and AC are the same age, replace both together. You’ll get matched efficiency, a single warranty start date, and contractors often offer $500-$1,000 discounts for combo installations. Many of Missouri’s best home improvement investments come from projects with strong ROI — and HVAC replacement ranks near the top.
Choosing a Contractor in Missouri
Missouri requires HVAC contractors to hold a mechanical license, but licensing requirements vary by municipality. Kansas City and St. Louis have their own licensing requirements on top of state standards. Check these credentials:
- Missouri HVAC license or municipal mechanical license
- EPA 608 certification (required for handling refrigerant)
- NATE certification (North American Technician Excellence — voluntary but indicates training quality)
- Manufacturer dealer certifications (Trane Comfort Specialist, Lennox Premier, Carrier Factory Authorized, etc.)
- Workers’ compensation and liability insurance (ask for certificates)
Manufacturer-authorized dealers can offer extended warranties (10-12 years parts and labor) that non-authorized installers cannot. This matters because the compressor — the most expensive single component — typically has a 10-year parts warranty, but labor to replace it costs $800-$1,500. A labor warranty covers that. For more tips on selecting home service providers, see the home services guide.
How HVAC Affects Home Value in Missouri
A new HVAC system recovers 35-50% of its cost at resale. But like roofing, the real value is defensive — buyers discount aggressively for old or failing HVAC. An inspector flagging a 20-year-old furnace with a heat exchanger crack will torpedo a sale or trigger a $5,000-$10,000 price reduction.
Missouri buyers increasingly ask about energy efficiency, utility bills, and equipment age during showings. A new high-efficiency system with transferable warranty is a selling point. An ancient system is a negotiation liability. If you’re planning to sell your home, a working, modern HVAC system removes one of the biggest inspection concerns.
First-time buyers should also check for available grants and programs that may help offset both purchase and improvement costs.
Frequently Asked Questions
How long does HVAC installation take in Missouri?
A standard furnace or AC replacement takes one day — typically 6-10 hours. Replacing both furnace and AC together takes 1-2 days. If ductwork modifications, electrical upgrades, or zoning system installation are needed, add 1-2 additional days. Scheduling during off-peak months (March-April or October-November) ensures faster turnaround because contractors have more flexibility in their schedules.
Is a heat pump worth it in Missouri’s cold winters?
Modern cold-climate heat pumps work efficiently down to 5-15F, which covers most Missouri winter days. During the coldest nights (sub-zero), a dual fuel system switches to gas backup. For most Missouri homeowners, a dual fuel heat pump system offers the lowest combined annual heating and cooling costs. The upfront premium over a standard furnace/AC combo is $2,000-$4,000, but federal tax credits and utility rebates can offset most of that difference. Annual energy savings of $200-$500 provide further payback over the system’s 15-20 year life.
What SEER2 rating should I choose for Missouri?
The minimum allowed is 14.3 SEER2. For most Missouri homeowners, a 16-17 SEER2 system hits the sweet spot between upfront cost and energy savings. The jump from 14.3 to 16 SEER2 saves about $100-$150 per cooling season and costs $800-$1,200 more upfront — it pays back in 6-10 years. Going above 18 SEER2 makes sense only if you plan to stay in the home 10+ years and have high cooling bills, or if the utility rebate significantly offsets the cost difference.
How do I know if my HVAC system is the right size for my home?
A properly sized system runs in long, steady cycles during peak weather — about 15-20 minute run times on the hottest summer day. Signs of an oversized system include short run times (5-10 minutes), high humidity despite cool air, and uneven temperatures. Signs of an undersized system include the unit running constantly without reaching the set temperature and hot/cold spots throughout the home. A Manual J load calculation ($150-$300) by a certified technician determines the correct size based on your home’s square footage, insulation, window area, orientation, and local climate data.
Do I need a permit for HVAC installation in Missouri?
Most Missouri cities require a mechanical permit for HVAC installation or replacement. Kansas City, St. Louis, Springfield, Columbia, and their surrounding suburbs all require permits and inspections. Permit costs range from $50-$200. Rural unincorporated areas may not require permits. The contractor should pull the permit and schedule the inspection — if a contractor tells you a permit isn’t needed in a city or suburb, verify that claim with your local building department before proceeding. Unpermitted work can affect your home insurance and create problems at resale.