How Much Does Boiler Replacement Cost in 2026?

By Michael JohnsonUpdated November 11, 20269 sources comparedHow we estimate

Most homeowners pay $3,500 to $9,000 to replace a boiler, with a national midpoint of about $6,100 installed. That is the median of the averages published by ConsumerAffairs ($5,750), Angi ($5,915), HomeGuide ($6,100), Fixr ($6,100) and Modernize ($8,500 for gas). The biggest price drivers are fuel type, whether you choose a condensing or combi model, steam versus hot water, and what the old installation leaves behind: an unlined chimney, tired piping or asbestos insulation.

Boiler replacement cost by type and fuel

The table compiles installed prices (unit plus labor) from six cost guides. The QuoteRuler range is where those sources overlap for a typical replacement on existing radiators or baseboard.

Modernize's figures are the highest across the board. Its gas boiler average of $8,500 includes venting, controls and startup, while the other guides lean toward simple swaps. The combi row shows the widest spread: Angi and Fixr start at $2,600, HomeGuide and Modernize at $6,000 or more. That gap likely reflects whether the quote includes domestic hot-water piping changes.

Cost by home size

Boilers are sized by heat loss, not just square footage, but home size is a useful first estimate:

The three guides agree closely here. Angi notes the cost rises by roughly $500 for every additional 500 sq ft. Ask for a room-by-room heat-loss calculation (HomeGuide prices a Manual J at $200–$500), because old boilers were often oversized and a smaller replacement can cost less and cycle less.

Condensing vs. non-condensing

A condensing boiler recovers heat from its exhaust and reaches 90% AFUE or higher. HomeGuide puts condensing units at $1,900–$7,000 for the equipment alone, against $1,200–$5,000 for non-condensing. Condensing boilers vent through plastic pipe out a side wall and need a condensate drain ($200–$600, HomeGuide). They deliver their best efficiency with lower water temperatures, which suits systems with plenty of radiator surface or radiant floors.

Non-condensing boilers usually keep venting into the chimney. If the chimney is unlined or the old liner is damaged, the inspector may require a new liner: $1,500–$4,000 (HomeGuide). Our chimney repair cost guide covers liner options in more detail.

Combi vs. heat-only boilers

A combi boiler heats the house and makes domestic hot water on demand, so you can retire a separate water heater. Fixr says combis suit smaller homes; in larger homes with several bathrooms, a heat-only boiler paired with an indirect tank keeps up better. HomeGuide prices an indirect hot-water tank at $1,200–$4,000 installed. If your water heater is also near the end of its life, compare this option with our water heater replacement cost guide.

Steam vs. hot water

Older city homes often have one-pipe or two-pipe steam systems. Steam boilers cost more: HomeGuide lists the unit at $1,800–$6,000 versus $1,200–$4,000 for hot water, and Modernize prices installed steam boilers at $7,000–$12,500. Steam boilers run at higher temperatures and are standard-efficiency models, and the near-boiler piping has to be built to the manufacturer's specification, which takes a technician who knows steam. Converting a steam system to hot water means repiping and often new radiators, which adds well beyond the price of the boiler itself.

Labor vs. materials

Boilers are labor-heavy. ConsumerAffairs puts labor at 40% to 50% of the total, or about $2,300–$2,900, against equipment of roughly $2,900–$3,450. Fixr gives $1,000–$3,500 for labor, usually including removal, HomeGuide $1,200–$3,200 and This Old House about $2,000. Plumbers and heating technicians bill $45 to $250 an hour depending on the source and market (HomeGuide, Angi).

We use a labor share of 45% in our state adjustments, in the middle of the ConsumerAffairs range. Steam work, relocations and fuel switches run higher; a straight electric swap runs lower. Fixr says most replacements take 4 to 6 hours, and up to 4 days when the boiler is moved or the fuel changes.

What drives the price up or down

• Efficiency and type. Condensing and combi boilers sit at the top of the table. Expect a condensing gas boiler to cost a few thousand dollars more than a standard one.
• Chimney liner. $1,500–$4,000 if a non-condensing boiler vents into an old flue (HomeGuide).
• Piping and radiators. Near-boiler repiping, new valves or radiator changes add $500–$2,500 (Fixr). HomeGuide prices replacement radiators at $250–$500 each.
• Zoning. Adding zones with valves or circulators costs $1,700–$4,500 (HomeGuide).
• Fuel switching. A new gas line hookup runs $0–$2,000, free if the utility covers it; removing an old oil tank costs $400–$3,400, and a new propane tank $1,200–$4,500 (HomeGuide).
• Electrical capacity. Electric boilers can need a 200-amp panel upgrade: $1,300–$3,000 (Fixr).
• Removal. $200–$500 for removal and disposal when not included (HomeGuide, Fixr). Heavy cast-iron sectional boilers in tight basements can land at the top of that range.
• Brand. Installed prices overlap heavily: Burnham runs $2,900–$8,700, Navien $3,200–$8,200, Peerless $3,200–$9,200 and Utica $2,400–$10,600 (HomeGuide).

Old cast-iron boilers and asbestos

Old boilers and the pipes leading from them were often insulated, and that insulation can contain asbestos. The EPA's asbestos guidance specifically mentions pipe, furnace and boiler insulation, says repairs and removal should be done only by people trained to handle asbestos, and warns that improper removal can increase exposure. If you don't know what the insulation on your boiler or pipes is made of, have it tested before demolition starts.

Angi prices targeted asbestos removal at $1,150–$3,000 (about $2,100 on average). Abatement is usually a separate contractor and a separate visit, so build it into your schedule. See our asbestos removal cost guide for testing and abatement details.

Boiler replacement cost by state

Heating contractors' rates vary widely from state to state. The table below starts from our national range, compiled from the sources above, and adjusts only the labor portion (45%) using the Bureau of Economic Analysis Regional Price Parities for each state.

Treat these as starting points, especially in big metro areas where access and permit costs can push prices above the state figure.

Repair or replace your boiler?

Fixr puts the average boiler lifespan at about 15 years and boiler repairs at about $450, against $6,100 for a replacement. It suggests replacing a boiler that is past 10 to 15 years old, keeps breaking down or is no longer the right size. A leaking cast-iron section or a cracked heat exchanger usually ends the repair conversation. A well-maintained cast-iron boiler with a failed circulator, igniter or aquastat is often worth fixing.

This is not a DIY job. Boiler replacement involves gas or oil connections, combustion venting, pressure-relief valves and carbon monoxide risk, and most jurisdictions require a permit and inspection. Hire a licensed heating contractor or plumber, and on gas jobs make sure the installer is licensed for gas work.

Thinking about switching to forced air instead? HomeGuide prices a boiler-to-furnace conversion at $10,000–$30,000 because it requires new ductwork. Our furnace replacement cost guide covers furnace prices if you're weighing that route.

How to save money on a new boiler

• Don't count on the federal tax credit. The 25C credit offered up to $600 for a qualifying gas, propane or oil hot-water boiler, but the IRS confirms it covered only property placed in service through December 31, 2025.
• Look for utility and state rebates. Some gas utilities and state programs still rebate high-efficiency boilers. Search the ENERGY STAR Rebate Finder by ZIP code and check whether pre-approval is required.
• Replace before it fails. A planned summer or early-fall replacement avoids emergency pricing and leaves time for abatement or liner work.
• Right-size it. A heat-loss calculation can justify a smaller boiler than the one you have.
• Stay with your fuel and location unless operating savings clearly justify the conversion costs.
• Get three itemized quotes for the same boiler type and output so you can compare like with like.

How to compare boiler quotes

A fair quote should list:

• Brand, model, output (BTU/h or MBH), AFUE and whether it is condensing.
• Removal and disposal of the old boiler, and who handles any asbestos.
• Venting: reuse of the chimney, a new liner or new PVC venting.
• Near-boiler piping, circulators, expansion tank, relief valve and low-water cutoff (on steam).
• Controls: outdoor reset, thermostats and zone valves.
• Permit, inspection and startup combustion test.
• Manufacturer warranty on the heat exchanger and the installer's labor warranty.

Red flags: sizing the new boiler by the old nameplate without a heat-loss calculation; no mention of venting or liner requirements; tearing out pipe insulation without testing it; a steam quote from a contractor who doesn't mention near-boiler piping; or a 2026 quote that still subtracts a federal tax credit.

Hidden costs people forget

• Chimney liner for a non-condensing boiler: $1,500–$4,000.
• Asbestos testing and abatement around old boilers and pipes: $1,150–$3,000.
• Indirect water heater if you go with a heat-only boiler and retire the old tank: $1,200–$4,000.
• Condensate drain for condensing models: $200–$600.
• Oil tank removal if you switch away from oil: $400–$3,400.
• Annual service to protect the warranty: $200–$500 (Fixr); Angi lists basic maintenance visits at $75–$125.

Bottom line

A typical boiler replacement costs $3,500 to $9,000 installed, and about $6,100 is a fair national midpoint. Standard gas and propane boilers sit at the low end; condensing, combi and steam boilers at the top. Budget separately for a chimney liner, piping changes or asbestos abatement if your system is old. Get three itemized quotes that include sizing, venting and removal before you choose.