Converting a boiler to forced-air heat typically costs $10,000-$25,000, with many projects averaging about $16,000. The final price depends mainly on whether ducts can be installed easily, the furnace capacity and efficiency, and the amount of boiler removal and house repair required.
| Item | Low | Average | High | Notes |
|---|---|---|---|---|
| Complete conversion | $10,000 | $16,000 | $25,000 | Furnace, ductwork, controls, and typical removal |
| New ductwork | $3,000 | $7,000 | $12,000 | About $20-$50 per linear ft, depending on access |
| Gas furnace installed | $3,500 | $5,500 | $8,500 | Common residential equipment and installation |
| Boiler removal | $500 | $1,200 | $2,500 | Higher with difficult access or extensive disposal |
What a boiler-to-furnace conversion typically costs
A straightforward conversion in a 1,500-2,000-square-foot home often falls around $10,000-$17,000 when installers can route ducts through an attic, basement, or existing chases. Homes needing concealed duct runs, finished-wall repairs, or electrical and fuel upgrades can reach $18,000-$25,000 or more.
Most of the budget goes to installing a complete air-distribution system, not just buying a furnace. A typical estimate assumes a mid-efficiency gas furnace, standard registers, ordinary site access, and no major asbestos abatement or structural work. High-efficiency equipment, a larger home, or a second floor with difficult routing can raise the quote.
Assumptions: Typical U.S. labor rates, gas available at the home, standard residential materials, and no major structural changes.
How furnace, duct, and removal charges add up
Contractors may bundle labor and materials, so line items are not always directly comparable. The ranges below show common installed or project charges; duct pricing varies with layout and whether runs are exposed or concealed.
| Quote component | Low | Average | High |
|---|---|---|---|
| Gas furnace and installation | $3,500 | $5,500 | $8,500 |
| Ducts, plenums, and registers | $3,000 | $7,000 | $12,000 |
| Boiler disconnection and disposal | $500 | $1,200 | $2,500 |
| Thermostat, wiring, and controls | $300 | $800 | $1,500 |
| Permits and inspection | $100 | $400 | $1,000 |
Ask whether duct sealing, balancing, condensate drainage, and startup testing are included. A low quote may exclude finish repairs, permit fees, or removal of old radiators and piping. Labor can be represented as ; HVAC labor commonly runs about $75-$150 per hour, though full-project bids are more usual.
How home size and duct routes change the quote
Heating capacity and duct layout should be based on a load calculation, not a simple square-foot rule. A 1,200-square-foot home may need a smaller furnace and fewer branches than a 2,500-square-foot home, but insulation, windows, ceiling height, and climate also affect sizing.
Difficult duct access can add several thousand dollars even when the furnace itself is unchanged. Open basements and accessible attics tend to cost less than finished ceilings or homes with no usable chases. A project needing more than 150-200 linear feet of duct, multiple return-air paths, or extensive drywall repair can exceed the typical range.
Equipment choices matter too. A basic single-stage furnace generally costs less than a variable-speed model, while high-efficiency equipment may require a PVC vent, condensate drain, and compatible controls. Verify that the quote specifies furnace capacity, efficiency rating, and included duct modifications.
What regional labor rates and access can add
Prices vary by local wages, climate, housing stock, and contractor availability. Dense Northeast and West Coast markets may run roughly 10%-25% above a national midrange, while some lower-cost rural markets may come in 5%-15% below it. These are planning comparisons, not guaranteed regional rates.
Local duct-installation conditions often matter more than the state’s average labor rate. Older homes with plaster walls, tight framing, or limited basement access typically require more labor than homes with open utility areas. In cold regions, contractors may also recommend a larger capacity range or more careful air balancing; that does not automatically justify oversized equipment.
How many workdays the conversion usually takes
A crew of two or three may complete a simple conversion in 2-4 working days. Adding ducts through finished areas, relocating equipment, or repairing surfaces can extend work to 5-8 days, sometimes with separate visits for inspection or follow-up.
Request a written schedule that identifies when heat will be unavailable. Labor and project coordination are usually included in the installed price, but some firms charge separately for difficult removal or unusual access. Confirm whether the crew will cap old water lines, remove radiators, protect floors, and haul away debris.
Extra charges for asbestos, gas lines, and cooling
Hazardous-material testing or abatement is not usually part of a standard conversion. If asbestos-containing insulation or boiler materials are suspected, qualified inspection and removal can add hundreds to several thousand dollars depending on the material and area. Do not allow ordinary demolition to disturb suspected asbestos.
Gas piping, electrical circuits, venting, or a new condensate drain may add about $300-$2,000 when upgrades are needed. Adding central air conditioning at the same time can cost roughly $3,000-$7,000 for a compatible coil and outdoor unit, with more for complex duct changes. Get these possible extras priced separately before approving the base conversion.
Forced-air conversion compared with keeping hydronic heat
Keeping a functioning boiler and replacing it with a new boiler can cost about $5,000-$12,000, depending on capacity, venting, and piping work. That option avoids the cost of new ducts and retains radiator or baseboard distribution. A boiler with localized failures may also be repairable, often for a few hundred to a few thousand dollars, depending on the component.
Forced air can make sense when the home needs ducts for central cooling or the boiler system is failing extensively. It is not automatically cheaper to operate: bills depend on fuel, equipment efficiency, thermostat settings, and the home’s heat loss. Compare the full conversion quote with a boiler replacement quote rather than comparing furnace equipment prices alone.
Ways to hold the conversion budget near the low end
Ask two or three licensed contractors to quote the same scope, including furnace capacity, duct locations, boiler disposal, permits, and finish repairs. Have each identify exclusions and provide equipment model numbers. Comparing bids on an identical scope makes unusually low or high allowances easier to spot.
Keep existing chases and open utility routes when practical, and avoid adding cooling or premium controls unless they solve a clear need. Schedule work before an emergency if possible, since urgent winter replacement can limit contractor choice. Do not cut costs by skipping load calculations, return-air sizing, permits, or commissioning; poor airflow can undermine comfort and equipment performance.