Furnace Replacement Cost in St. Louis, MO (2026)
A gas furnace, installed, before rebates
$3,750to$4,800
From a public baseline and 131 City permits. How prices are made.
The low and the high are the spread of equipment and labor in the public baseline for a gas furnace in 2026.
Missouri Rebates in 2026
Enrollment for 2026 is open. The program year runs from October 1 to September 30. The amounts are from the Missouri East form printed in October 2025. Confirm them on the current form before you count on them. Funding is limited.
Spire (Missouri East) pays $300 per furnace on a gas furnace at 96% AFUE or greater. After the rebate the typical price for a gas furnace is $3,750. Checked October 19, 2026. How to apply.
| Equipment | Minimum efficiency | Rebate |
|---|---|---|
| Gas furnace | 96% AFUE or greater | $300 per furnace |
| Gas furnace | 92% to 95.99% AFUE | $200 per furnace |
Every Program a St. Louis Homeowner Can Use
- Ameren PAYS pays up to $2,000 per system. Closed for 2026.
- Spire furnace rebates pay up to $300 per furnace. Open now.
- Missouri HOMES and HEEHR have not published their amounts yet. Not open yet.
- Federal 25C credit gives no credit for a 2026 install. Ended.
What It Costs
All 7 systems, low to high
| System | Low | Typical | High | Range drawn |
|---|---|---|---|---|
| Heat pump, ducted | ||||
| 2-ton heat pump 15 SEER | $6,500 | $11,750 | $17,000 | |
| 3-ton heat pump 15 SEER | $7,450 | $13,350 | $19,250 | |
| 4-ton heat pump 15 SEER | $8,400 | $14,950 | $21,500 | |
| 5-ton heat pump 15 SEER | $9,400 | $16,550 | $23,700 | |
| Other systems | ||||
| Central AC only, 3 ton 16 SEER | $4,150 | $6,900 | $9,700 | |
| Gas furnace only, 80,000 BTU 95% AFUE | $3,750 | $4,050 | $4,800 | |
| Mini-split, one zone, 12,000 BTU 20 SEER | $4,500 | $7,500 | $10,500 | |
Sources today: public baseline: NREL National Residential Efficiency Measures Database, 2024 release (read via hvacbase.org, 2026-10-19) · 131 City permits (2026-09-17 to 2026-10-16). Two more sources join as they arrive: Verified contractor ranges and homeowner-reported quotes. 2023 dollars, national. No metro factor is applied in this version. How prices are made.
Permits
Your contractor pulls the permit. The City issues mechanical permits only to contractors it licenses. The application fee is $25. The most common total fee on a replacement permit was $40 (97 of 131 permits). St. Louis County Department of Public Works covers homes in St. Louis County outside the city, with its own schedule.
The City issued 131 residential replacement permits in the 30 days from September 17, 2026 to October 16, 2026. Contractors declared a job value of $6,495 to $12,839 on the middle half of them, with a median of $9,954. Declared valuation on the permit. Contractors under-report it, so read it as a floor. Source: City of St. Louis Building Division · the open permit data.
Common Questions
How much does a gas furnace cost installed in St. Louis?
The installed range is $3,750 to $4,800, with a typical price of $4,050. This is the national public baseline in 2023 dollars. After the rebate the typical price for a gas furnace is $3,750.
What does the Spire (Missouri East) gas furnace rebate pay in 2026?
$300 per furnace at 96% AFUE or greater, through Spire furnace rebates. The program year runs from October 1 to September 30. The amounts are from the Missouri East form printed in October 2025. Confirm them on the current form before you count on them. Funding is limited.
Is there a federal tax credit for a gas furnace in 2026?
The IRS allows the credit for property placed in service before December 31, 2025. A heat pump installed in 2026 gets no federal credit. The utility rebate is the money on the table in 2026.
Do I need a permit to replace a gas furnace in the City of St. Louis?
Yes. The City issues mechanical permits only to contractors it licenses. The most common total fee was $40. The City issued 131 residential replacement permits in 30 days.
What do the other systems cost in St. Louis?
A 3-ton central air conditioner runs $4,150 to $9,700, typical $6,900. A 3-ton heat pump runs $7,450 to $19,250, typical $13,350. A one-zone mini-split runs $4,500 to $10,500, typical $7,500. Each range is installed, before rebates.
What did contractors declare on the permits?
A median of $9,954 on 131 replacement permits. Declared valuation on the permit. Contractors under-report it, so read it as a floor.
Contractors in St. Louis
47 contractors pulled a residential replacement permit in the City in the last 30 days. A Verified contractor is one that published its terms here. Contractors in St. Louis.
Range quarter 2026-Q4, updated October 19, 2026. Last change: First page. Range 2026 Q4 from the public baseline and 131 City permits. Four rebate pages. Changelog. Source page: https://hvacvisit.com/missouri/st-louis/furnace-replacement-cost. Cite a range with a link to the page it is on. Do not republish a page, a table or a dataset in full.