Cost to Boiler Replacement in St. Louis, MO (2026)
If you’re budgeting a boiler replacement in St. Louis, most projects run $5,668-$11,726, 2% below the $8,200 national average. What moves that number most is usually one thing: Fuel Type. On its own it can swing the cost by $1,500 - $4,000, so that’s the decision to slow down on before you sweat the smaller stuff.
Easiest place to save: Get quotes from at least 3 HVAC contractors - prices for the same boiler can vary $1,500-$3,000 between installers
In the Midwest (where St. Louis sits): Strong boiler market with competitive pricing.
$5,668-$11,726 in St. Louis
2% below the national average · 0.98x cost multiplier
In St. Louis, a boiler replacement runs $5,668 to $11,726 on average - about 2% below what homeowners pay nationwide. The Midwest market's labor costs account for most of the gap, with material pricing and local permitting fees adding to the spread. Use the cost table below to compare budget, mid-range, and premium options side by side.
Cost Breakdown in St. Louis
| Line Item | Low | Mid | High |
|---|---|---|---|
| Materials | $2,068 | $4,230 | $7,990 |
| Labor | $1,890 | $2,939 | $4,199 |
| Permits | $235 | $329 | $470 |
| Total | $4,193-1% vs. national avg | $7,498-2% vs. national avg | $13,129-3% vs. national avg |
Budget
Standard-efficiency gas boiler (80-85% AFUE), basic installation with existing connections
Mid-Range
High-efficiency condensing gas boiler (90-95% AFUE), new venting, updated controls
Premium
Top-tier condensing boiler (95%+ AFUE), zoned system with smart controls, new piping, indirect water heater
Material Options
Material prices below are national averages; availability in St. Louis may shift costs slightly.
| Material | Cost/Unit | Best For |
|---|---|---|
| Standard Gas Boiler (80-85% AFUE) | $2,000-$4,000 | Budget-conscious replacements where the existing venting worksLowest upfront cost, simple installation, widely available parts |
| Condensing Gas Boiler (90-98% AFUE) | $3,500-$8,000 | Homeowners planning to stay 5+ years who want long-term savingsLowest operating costs, qualifies for utility rebates, smaller footprint |
| Oil Boiler | $3,000-$7,000 | Rural homes without natural gas accessHigh heat output, works without gas line, reliable in cold climates |
| Electric Boiler | $1,500-$5,000 | Small homes, mild climates, or areas with cheap electricityNo combustion venting needed, compact, zero on-site emissions, quiet |
| Combi Boiler (Heat + Hot Water) | $3,000-$7,500 | Small to mid-size homes wanting to free up mechanical room spaceEliminates separate water heater, saves space, on-demand hot water |
Other Projects in St. Louis
St. Louis Estimate
Typical Range
$5,668-$11,726
vs. National Average
2% below national
Cost Multiplier
0.98x
This 0.98x estimate prices St. Louis labor from BLS Occupational Employment and Wage Statistics (May 2025) and applies a lighter regional adjustment to materials and permits, which vary less by metro than labor does. Actual bids vary by contractor, project scope, and timing.
See national average costs →