Can I replace a steam or hot-water boiler with a heat pump in a Massachusetts home?

Yes — and it's one of the most common retrofits in MA's older housing stock. Because boilers heat with water or steam through radiators or baseboard (not ducts), the standard replacement is ductless mini-split heat pumps: one outdoor condenser feeding wall or ceiling heads in each zone, sized to a Manual J load. You don't need existing ductwork. Many homeowners keep the boiler connected solely for domestic hot water and let the heat pump carry all the space heating.

Is a heat pump cheaper to run than an oil or gas boiler in Massachusetts?

Versus oil, almost always — a cold-climate heat pump runs roughly $1,200–$2,400/year in MA electricity vs $2,500–$4,000/year for an oil boiler at $3.80/gallon. Versus a modern condensing gas boiler the margin narrows, but the heat pump still typically wins on operating cost and adds central cooling a boiler cannot provide. Your utility's seasonal Heat Pump Rate widens the gap further every November 1 through April 30 — Eversource, National Grid and Unitil enroll most heat pump households automatically once the Mass Save rebate is processed.

Do I lose the Mass Save rebate if I keep my boiler?

It depends how you keep it. If the boiler stays as your primary/backup space-heating source, the heat pump is a "partial-home" install — eligible for the $1,125/ton tier (capped at $8,500) plus $500 sizing and weatherization bonuses. If the heat pump becomes the sole space-heating source and the boiler is retired or kept only for domestic hot water, you qualify for the larger "whole-home" tier at $2,650/ton (also capped at $8,500). Keeping the boiler for hot water only does not disqualify the whole-home rebate.

What about steam heat specifically — is that harder to convert?

Steam systems (common in pre-1930 MA homes and triple-deckers) can't be directly "upgraded" to a heat pump because there's no water loop to reuse — but that's fine, because the ductless mini-split path ignores the existing distribution entirely. You add independent heat pump zones and either decommission the steam boiler or keep it for a single winter as belt-and-suspenders backup. One-pipe steam radiators can stay in place, unused, or be removed during renovation.

Should I keep the boiler for domestic hot water?

Often yes, at least initially — if your boiler also makes your domestic hot water (via a tankless coil or indirect tank), you may keep it running just for that while the heat pump handles space heating. Longer term, pairing the heat pump with a heat-pump water heater fully retires the boiler and its annual service cost. Either way, retiring the boiler from space-heating duty is what unlocks the whole-home rebate tier.

Will a heat pump keep my old, drafty Massachusetts house warm without the boiler?

Yes, if the system is sized to a real Manual J against your city's winter design temperature and you specify a cold-climate model on the Mass Save HPQPL. Older homes benefit enormously from pairing the heat pump install with weatherization (air sealing + insulation) — which also earns the $500 weatherization bonus. Sized backup resistance heat covers the rare sub-zero night.

Heat Pump vs Boiler in Massachusetts (2026)

By MassHVAC Editorial Team Reviewed by MassHVAC Editorial Team Last updated 2026-09-19

Heat with a forced-air furnace instead? This page is about hydronic boilers (radiators, baseboard, steam). For ducted systems, read heat pump vs furnace instead.

Factor	Cold-climate heat pump	Oil boiler	Gas boiler (condensing)
Install cost (whole-home)	$18,000–$28,000	$8,000–$16,000	$7,000–$14,000
Mass Save rebate (2026)	Up to $8,500	None	Small (high-efficiency only)
Net install cost (after rebate)	$9,500–$17,500	$8,000–$16,000	$6,500–$13,500
Annual operating cost (MA)	$1,200–$2,400	$2,500–$4,000	$1,600–$2,600
Provides cooling?	Yes	No	No (separate AC needed)
Needs ductwork?	No (ductless mini-split)	No (hydronic)	No (hydronic)
HEAT Loan eligible?	Yes (0% APR up to $25K)	No	Limited

Why a boiler conversion is different from a furnace conversion

A furnace blows hot air through ducts; a boiler moves heat as hot water or steam through radiators and baseboard. That single fact reshapes the whole project. With a furnace, a ducted heat pump can sometimes reuse existing ductwork. With a boiler, there's no ductwork to reuse — so the dominant Massachusetts path is ductless mini-splits, which deliver heating and cooling zone-by-zone without any ducts at all. This is why so many pre-1940 MA homes, triple-deckers, and steam-heated colonials end up on mini-splits: it's the retrofit that fits the building.

Steam vs. hot-water boilers

Hot-water (hydronic) boilers — the most common MA boiler type, feeding baseboard or cast-iron radiators. Efficient modern condensing versions exist, but they still can't cool and don't qualify for the big rebate. Converting means adding mini-split zones and retiring or repurposing the boiler.
Steam boilers — common in older Boston, Worcester, and Springfield housing. Steam can't be made high-efficiency and is expensive to run. There's nothing to "upgrade" into a heat pump, so you simply add independent mini-split zones and decommission (or briefly keep) the steam boiler. The old radiators can stay in place unused.

Keeping the boiler for domestic hot water

Many MA boilers also make the home's hot water via a tankless coil or an indirect tank. A sensible phased approach: install the heat pump for all space heating now, and leave the boiler running only for domestic hot water until it's due for replacement — at which point a heat-pump water heater retires it entirely. Crucially, moving all space heating to the heat pump is what qualifies you for the whole-home rebate tier ($2,650/ton up to $8,500); keeping the boiler for hot water only does not forfeit it.

The rebate math that favors the heat pump

A like-for-like boiler replacement earns little or nothing from Mass Save. A cold-climate heat pump earns up to $8,500, plus 0% HEAT Loan financing up to $25,000, plus (for income-qualified households) Enhanced caps up to $16,000. That rebate stack is often the deciding factor: it narrows or erases the heat pump's higher sticker price while adding cooling and cutting operating cost.

Massachusetts incentives

Mass Save rebates that apply to a boiler-to-heat-pump conversion

See the full Mass Save rebates hub

Verified 2026-09-19

Most homes

Whole-Home Heat Pump Rebate

$2,650 /ton

Capped at $8,500 per home

The installed heat pump must be the sole source of heating and cooling for the spaces served. Equipment must be ENERGY STAR Cold Climate certified and listed on the Mass Save Heat Pump Qualified Products List (HPQPL). A Manual J load calculation is needed to qualify for the sizing bonus and is industry-standard practice on Mass Save projects.

Partial-Home / Supplemental Heat Pump Rebate

$1,125 /ton

Capped at $8,500 per home

Heat pump installed alongside an existing primary heating system. Equipment must be on the HPQPL. Lower per-ton rebate reflects supplemental rather than sole-source use.

Basic Heat Pump Rebate

$250 /ton

Capped at $2,500 per home

New for 2026. Applies to replacing an existing heat pump with a new qualified HPQPL-listed heat pump, or conditioning a previously unconditioned space.

$500 Right-Sized Equipment Bonus Partial-home

Partial-home installs only. Equipment must be sized to meet 90–120% of the total heating load at the outdoor design temperature, documented via an ACCA Manual J load calculation submitted with the rebate application.

$500 Weatherization Bonus Partial-home

Partial-home installs only. Requires a Mass Save Home Energy Assessment plus installation of the recommended weatherization (typically air sealing and insulation) within one year prior to or up to six months after the heat pump installation.

Financing

Mass Save HEAT Loan

0% APR up to $25,000

Below 135% of State Median Income: 7 years (84 months)
135%–300% of State Median Income: 5 years (60 months)
Over 300% of State Median Income: 3 years (36 months)

Subject to bank underwriting through participating Massachusetts lenders. Covers equipment + installation costs for qualifying high-efficiency upgrades (heat pumps, ductless mini-splits, insulation, water heaters, and batteries enrolled in ConnectedSolutions). A Home Energy Assessment is mandatory before financing a whole-home heat pump. Households below approximately 81% SMI typically route to Mass Save's no-cost / enhanced-rebate programs rather than the HEAT Loan.

No federal heat pump tax credit applies in 2026.

Section 25C Energy Efficient Home Improvement Credit (heat pump portion) (30% of cost up to $2,000 annually for qualifying heat pump installations (inflation reduction act expansion)) ended for property placed in service after 2025-12-31 under the One Big Beautiful Bill Act (P.L. 119-21).
Section 25D Residential Clean Energy Credit (geothermal portion) (30% of installed cost for ground-source (geothermal) heat pumps, with no dollar cap) ended for property placed in service after 2025-12-31 under the One Big Beautiful Bill Act (P.L. 119-21).

Status as of 2026-09-19: neither 25C nor 25D has been reinstated or replaced by Congress. Pending bills (e.g. H.R. 616) have not advanced. Pre-2026 §25D installs may carry forward unused credits.

Rebate amounts and eligibility verified 2026-09-19 against primary program documentation. We re-check before any publish.

Get a quote using these rates

When keeping the boiler still makes sense

A newer condensing gas boiler (under ~10 years, in good condition) that you're not ready to retire can be kept as backup in a dual-fuel setup — though that drops you to the partial-home rebate tier. And if you value radiator warmth and have no interest in cooling, a gas boiler can remain reasonable in the near term. Outside those cases, the heat pump wins on lifetime cost, comfort in summer, and rebate value. For the forced-air version of this decision, see heat pump vs furnace; for the deeper fuel-cost model, see the gas vs heat pump TCO guide.

Heat pump vs boiler FAQ

Can I replace a steam or hot-water boiler with a heat pump in a Massachusetts home?: Yes — and it's one of the most common retrofits in MA's older housing stock. Because boilers heat with water or steam through radiators or baseboard (not ducts), the standard replacement is ductless mini-split heat pumps: one outdoor condenser feeding wall or ceiling heads in each zone, sized to a Manual J load. You don't need existing ductwork. Many homeowners keep the boiler connected solely for domestic hot water and let the heat pump carry all the space heating.
Is a heat pump cheaper to run than an oil or gas boiler in Massachusetts?: Versus oil, almost always — a cold-climate heat pump runs roughly $1,200–$2,400/year in MA electricity vs $2,500–$4,000/year for an oil boiler at $3.80/gallon. Versus a modern condensing gas boiler the margin narrows, but the heat pump still typically wins on operating cost and adds central cooling a boiler cannot provide. Your utility's seasonal Heat Pump Rate widens the gap further every November 1 through April 30 — Eversource, National Grid and Unitil enroll most heat pump households automatically once the Mass Save rebate is processed.
Do I lose the Mass Save rebate if I keep my boiler?: It depends how you keep it. If the boiler stays as your primary/backup space-heating source, the heat pump is a "partial-home" install — eligible for the $1,125/ton tier (capped at $8,500) plus $500 sizing and weatherization bonuses. If the heat pump becomes the sole space-heating source and the boiler is retired or kept only for domestic hot water, you qualify for the larger "whole-home" tier at $2,650/ton (also capped at $8,500). Keeping the boiler for hot water only does not disqualify the whole-home rebate.
What about steam heat specifically — is that harder to convert?: Steam systems (common in pre-1930 MA homes and triple-deckers) can't be directly "upgraded" to a heat pump because there's no water loop to reuse — but that's fine, because the ductless mini-split path ignores the existing distribution entirely. You add independent heat pump zones and either decommission the steam boiler or keep it for a single winter as belt-and-suspenders backup. One-pipe steam radiators can stay in place, unused, or be removed during renovation.
Should I keep the boiler for domestic hot water?: Often yes, at least initially — if your boiler also makes your domestic hot water (via a tankless coil or indirect tank), you may keep it running just for that while the heat pump handles space heating. Longer term, pairing the heat pump with a heat-pump water heater fully retires the boiler and its annual service cost. Either way, retiring the boiler from space-heating duty is what unlocks the whole-home rebate tier.
Will a heat pump keep my old, drafty Massachusetts house warm without the boiler?: Yes, if the system is sized to a real Manual J against your city's winter design temperature and you specify a cold-climate model on the Mass Save HPQPL. Older homes benefit enormously from pairing the heat pump install with weatherization (air sealing + insulation) — which also earns the $500 weatherization bonus. Sized backup resistance heat covers the rare sub-zero night.

Related guides

Converting a boiler-heated Massachusetts home?

Comfitrust will design mini-split zones to your Manual J, plan whether to keep the boiler for hot water, and file the Mass Save rebate.

Get a free quote Or call (508) 501-7561

1 About your project

2 Your contact info