Boiler Replacement Cost: Types and Prices (2026)
💰 Cost Breakdown
| Item | Low | Average | High |
|---|---|---|---|
| Standard Gas Boiler (80–85% AFUE) A non-condensing cast-iron or steel gas boiler. Reliable and less expensive upfront, but uses more fuel than condensing models. Requires a chimney or B-vent for exhaust. Common replacement for older gas boilers in homes with existing chimney infrastructure. | $3,500 | $5,500 | $7,500 |
| High-Efficiency Condensing Gas Boiler (90–98% AFUE) Extracts extra heat from exhaust gases by condensing water vapor, achieving 90–98% efficiency. Requires PVC venting (through a sidewall, no chimney needed) and a condensate drain. Higher upfront cost, lower monthly fuel bills. Qualifies for some utility rebates. | $5,000 | $8,000 | $12,000 |
| Oil Boiler Common in the Northeast where natural gas isn't available. Oil boilers cost more to operate than gas but are the primary option in many areas. Requires an oil storage tank (existing or new) and annual nozzle/filter maintenance. | $4,000 | $6,500 | $9,000 |
| Electric Boiler Compact, quiet, and 99% efficient at the point of use. No combustion, no venting, no fuel storage. Best for small homes, additions, or areas with cheap electricity. Operating costs are typically higher than gas in most markets. | $2,500 | $5,000 | $8,000 |
| Combi Boiler (Heating + Hot Water) Provides both space heating and on-demand domestic hot water from a single unit, eliminating the need for a separate water heater. Saves space but may struggle to supply hot water to multiple fixtures simultaneously in large households. | $4,000 | $7,000 | $10,000 |
| Oil-to-Gas Conversion Switching from an oil boiler to a gas boiler when natural gas becomes available. Includes removing the oil tank, running a gas line, installing a new gas boiler, and updating venting. Higher upfront cost but lower long-term fuel costs. | $7,000 | $10,000 | $15,000 |
Standard Gas Boiler (80–85% AFUE)
A non-condensing cast-iron or steel gas boiler. Reliable and less expensive upfront, but uses more fuel than condensing models. Requires a chimney or B-vent for exhaust. Common replacement for older gas boilers in homes with existing chimney infrastructure.
High-Efficiency Condensing Gas Boiler (90–98% AFUE)
Extracts extra heat from exhaust gases by condensing water vapor, achieving 90–98% efficiency. Requires PVC venting (through a sidewall, no chimney needed) and a condensate drain. Higher upfront cost, lower monthly fuel bills. Qualifies for some utility rebates.
Oil Boiler
Common in the Northeast where natural gas isn't available. Oil boilers cost more to operate than gas but are the primary option in many areas. Requires an oil storage tank (existing or new) and annual nozzle/filter maintenance.
Electric Boiler
Compact, quiet, and 99% efficient at the point of use. No combustion, no venting, no fuel storage. Best for small homes, additions, or areas with cheap electricity. Operating costs are typically higher than gas in most markets.
Combi Boiler (Heating + Hot Water)
Provides both space heating and on-demand domestic hot water from a single unit, eliminating the need for a separate water heater. Saves space but may struggle to supply hot water to multiple fixtures simultaneously in large households.
Oil-to-Gas Conversion
Switching from an oil boiler to a gas boiler when natural gas becomes available. Includes removing the oil tank, running a gas line, installing a new gas boiler, and updating venting. Higher upfront cost but lower long-term fuel costs.
📊 Factors That Impact Cost
Fuel Type
High ImpactGas boilers are the least expensive to install and operate in most markets. Oil boilers cost more to run and require tank maintenance. Electric boilers are cheap to install but expensive to operate unless electricity rates are low. Propane falls between gas and oil.
Efficiency Rating (AFUE)
High ImpactHigher AFUE means more heat per fuel dollar but a higher purchase price. A 95% AFUE condensing boiler costs $1,500–$3,000 more than an 82% standard boiler but saves $200–$500/year in fuel, paying back the difference in 5–8 years.
System Size (BTU Output)
Medium ImpactResidential boilers range from 50,000–200,000 BTU. Larger homes, colder climates, and older/poorly insulated houses need higher output. Oversizing wastes fuel through short-cycling; undersizing leaves the house cold. A Manual J calculation determines the right size.
Venting and Piping Modifications
Medium ImpactSwitching from a chimney-vented standard boiler to a sidewall-vented condensing model requires new PVC venting and a condensate drain. If existing piping is undersized or corroded, replacement adds $500–$2,000 to the project.
Permits and Inspections
Low ImpactMost jurisdictions require a mechanical permit for boiler replacement ($50–$300). Some also require a plumbing or gas permit. Reputable contractors pull permits as part of the job — be wary of any contractor who suggests skipping this step.
💡 Money-Saving Tips
Replace in the off-season
Schedule boiler replacement in late spring or summer when HVAC contractors are less busy. You'll get faster scheduling, potentially lower labor rates, and more time to compare quotes without the pressure of a broken heating system.
Check for utility rebates and tax credits
Many gas utilities offer $300–$1,000 rebates for high-efficiency condensing boilers. Federal energy tax credits may apply for qualifying ENERGY STAR equipment. Check DSIRE (dsireusa.org) and your utility's website before purchasing.
Keep the existing distribution system if possible
If your radiators, baseboards, and piping are in good condition, replacing only the boiler saves thousands over a full system overhaul. A qualified installer can match a new boiler to your existing distribution with proper sizing.
Get three itemized quotes
Boiler replacement pricing varies significantly between contractors. Three written, itemized quotes let you compare equipment brands, warranty terms, and labor charges. Ask each contractor to specify the model, AFUE rating, and what's included in the price.