The short answer
In eastern Massachusetts a straightforward gas boiler replacement typically costs $6,000 to $12,000 installed. High-efficiency condensing boilers, combi units that also make hot water, oil boilers and oil-to-gas conversions run $9,000 to $16,000 or more. Mass Save rebates and a 0% HEAT Loan can take a meaningful bite out of the high-efficiency number. These are the ranges we see on the North Shore and around Boston; your exact price depends on the items below and is fixed in writing before any work starts.
What moves the price?
Two houses on the same street can get two very different quotes for a "new boiler." The equipment is only part of it. These are the variables that matter most:
- Fuel and efficiency. A standard 80–85% AFUE cast-iron gas boiler is the cheapest unit. A 95% condensing boiler costs more up front, needs PVC venting and a condensate drain, and saves fuel every month.
- Combi vs. boiler-only. A combi boiler heats the house and makes domestic hot water in one box, replacing a separate water heater. It costs more than a heat-only boiler but eliminates a second appliance.
- Venting and chimney. Old atmospheric boilers vented up a masonry chimney. Condensing units side-vent in plastic; if the water heater still uses the chimney, it may need a liner once the boiler leaves. That liner is a common surprise line item.
- Near-boiler piping and zoning. Replacing corroded supply and return piping, adding zone valves or circulators, a new expansion tank and air separator — the more the old install is reused, the lower the number.
- Steam vs. hot water. Steam boilers, common in pre-1940 Boston-area homes, are a different animal: heavier, priced higher, and they need a skimmer and careful near-boiler piping to run quietly.
- Oil-to-gas conversion. New gas line from the meter, utility coordination, oil tank removal and disposal. Highest range, but often the biggest long-term fuel savings.
- Permit and inspection. Required in Massachusetts for any boiler install. Modest, but it is on every honest estimate.
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How much does each boiler type cost?
Installed price ranges we quote around Lynnfield, the North Shore and Greater Boston. Equipment, labor, standard near-boiler piping, permit and haul-away included; chimney liners, fuel conversions and new zoning are extra.
| System | Typical installed range | Notes |
|---|---|---|
| Standard-efficiency gas boiler (80–85%) | $6,000 – $9,500 | Cast iron, chimney-vented; lowest up-front cost |
| High-efficiency condensing gas boiler (95%+) | $9,000 – $14,000 | Side-vented, eligible for the largest Mass Save rebates |
| Combi boiler (heat + hot water) | $9,500 – $15,000 | Replaces a water heater too; sized to hot-water demand |
| Oil boiler | $8,000 – $13,000 | Includes new oil line filter; tank not included |
| Steam boiler | $8,500 – $14,000 | Common in pre-war homes; near-boiler piping is critical |
| Oil-to-gas conversion | $12,000 – $18,000+ | Gas line, utility coordination, tank removal |
If a quote lands well outside these ranges in either direction, ask what is and is not included. A very low number often leaves out the permit, the chimney liner or the disposal of the old boiler.
What rebates and loans are available?
Massachusetts homeowners on a participating gas or electric utility can usually claim a Mass Save rebate on a qualifying high-efficiency boiler, and finance the balance through the Mass Save HEAT Loan at 0% interest over several years. Rebate amounts change year to year and depend on the equipment tier, so we confirm the current figures when we quote and handle the paperwork with you. The practical effect: the high-efficiency option often ends up costing little more per month than the basic one, while burning noticeably less gas.
Repair or replace?
Not every boiler that fails in January needs replacing. Use these rules of thumb:
- Under 12 years old and the failure is a part (circulator, gas valve, igniter, aquastat, relief valve) — repair. These are routine.
- 15–20+ years old and the repair is more than about a third of a new unit — replace. You are paying to keep an 80% machine running.
- Cracked heat exchanger or leaking sections — replace. There is no economical fix.
- Rising fuel bills with no change in use, rusty water in the system, frequent lockouts — start planning; it will pick its own moment otherwise.
We quote both paths when a repair is borderline so you can decide with the numbers in front of you.
What does replacement day look like?
- Site visit and written estimate. We size the boiler to the house (not just to the old nameplate), check the chimney and venting path, and price the options.
- Permit filed. Massachusetts requires it; we handle it.
- Install day. Drain the system, remove the old boiler, set the new one, re-pipe, vent, fill, purge air, fire and test every zone. Most jobs are one working day.
- Inspection and paperwork. The inspector signs off; we register the warranty and submit any rebate documents with you.
If your boiler is limping into another winter, an estimate now beats an emergency install in February. Precision Plumbing Solutions installs and replaces boilers across Essex, Middlesex, Suffolk, Norfolk and Plymouth Counties — see our boiler installation service, or read how tank and tankless water heaters compare if the hot-water side is on the list too.
Questions people ask
How long does a boiler replacement take?
Most like-for-like swaps are finished in one working day. A fuel conversion, a relocated boiler or new zoning can add a second day. In heating season we schedule so the house has heat again the same night.
Is a high-efficiency boiler worth it in Massachusetts?
Usually yes on natural gas: a 95% condensing boiler cuts fuel use roughly 15–25% versus an old 80% unit, and Mass Save rebates and the 0% HEAT Loan offset most of the price gap. The case is weaker on oil or with very low usage.
Can you replace an oil boiler with gas?
If gas service is on the street, yes. The conversion adds the gas line, meter coordination with the utility and oil-tank removal, which is why it sits at the top of the price range.
Do you pull the permit?
Yes. Boiler replacement requires a plumbing/gas permit and inspection in Massachusetts. We file it and schedule the inspector; the fee is on the estimate.
