The Mass Save HEAT Loan: 0% Financing for Massachusetts Home Upgrades

The Mass Save HEAT Loan lets a Massachusetts homeowner borrow up to $25,000 at 0% interest, repaid over as long as 7 years, to pay for a heat pump, a heat pump water heater, insulation, ENERGY STAR windows, or a home battery. It is financing, not free money, and that's the part people get backwards. A rebate puts cash back in your pocket. The HEAT Loan covers the rest of the bill at zero interest so you can spread it out instead of putting $20,000 on a credit card. Used together, they're how most MA homeowners actually afford to electrify.

This guide is about the loan itself, the amount, the term, what it covers, and who qualifies. For the dollars-back side, see our Massachusetts heat pump rebates guide, which owns the rebate amounts and the federal stack.

What is the Mass Save HEAT Loan?

The HEAT Loan is a 0% financing program run by the Mass Save Program Sponsors, the gas and electric utilities that fund Mass Save through your bill. You borrow money from a participating bank or credit union to pay for qualifying efficiency and electrification upgrades, and you pay it back over a fixed term with no interest.

Here's the distinction worth burning into your brain before you talk to a contractor:

• A rebate is money you get back after the work is done (or applied as an instant discount). You don't repay it.
• The HEAT Loan is a loan. You repay the principal, just at 0% instead of a bank's normal 8–12%.

So a $28,000 heat pump install with a $10,000 rebate leaves $18,000. The HEAT Loan can finance that $18,000 at 0% over up to 7 years. That's roughly $214 a month with no interest, versus a payment plan from a financing company that quietly bakes 9.99% into a higher sticker price.

Is it really 0% interest? What's the catch?

Yes, it's genuinely 0% to you, and the mechanism is worth understanding, because it explains the credit check. You don't borrow from Mass Save. You borrow from a participating lender at a normal market rate, and the Mass Save Program Sponsors pay that interest down to zero for the life of the loan. Per Mass Save's own lender documentation, the lender's rate is "set at the current prime rate... lenders then apply a margin... based on the borrower's FICO or Vantage scores," and the Sponsors then buy that interest down.

The practical catch: because a real bank is fronting the money, you go through a real loan application. The lender pulls your credit and decides whether to approve you. There's no single published minimum credit score from Mass Save, each participating lender sets its own bar, and they differ (some sit around the mid-600s, some higher). If your credit is thin or bruised, ask the lender directly about their floor before you count on the financing.

How much can you borrow, and for how long?

The HEAT Loan caps at $25,000 at 0% interest over a term of up to 7 years. Here's the shape of it at a glance:

Term	What Mass Save sets
Interest rate (to you)	0%
Maximum amount	$25,000
Maximum repayment term	7 years
Cap type	Lifetime, across all measures combined
Lender	A participating bank or credit union (not Mass Save)
Application	Online via myheatloan.com, then your chosen lender

The $25,000 is a lifetime cap, not per project

This is the detail installers tend to skip. The $25,000 ceiling, in place since January 1, 2025, is the total you can borrow through the HEAT Loan over the lifetime of your upgrades, not a fresh $25,000 for each project. Mass Save spells it out: "Customers can access the program more than once, but their loans combined cannot exceed the $25,000 maximum."

What that means for you: if you finance a $15,000 heat pump this year, you have $10,000 of HEAT Loan headroom left for future weatherization or a heat pump water heater, not another full $25,000. If you're planning a phased electrification over a few years, sequence the financing with that ceiling in mind, and don't let one big project eat the whole allowance unless you mean to.

What can you finance with it?

The HEAT Loan covers the efficiency and electrification measures Mass Save promotes. The eligible categories are:

• Heat pump projects, air-source heat pumps, ducted or ductless mini-splits
• Heat pump water heaters
• Weatherization, insulation and air sealing
• Pre-weatherization barriers, work needed before insulation can go in (knob-and-tube remediation, for example)
• ENERGY STAR certified replacement windows, but only alongside completed weatherization recommendations
• Residential batteries enrolled in ConnectedSolutions

If you're deciding between systems before you finance, our guides on central AC vs. a heat pump and ductless mini-splits lay out the tradeoffs for a Massachusetts climate. Swapping out an old boiler is another common reason homeowners reach for the loan.

One thing the list does not include in its own right: a like-for-like gas furnace or standard central AC swap is not the headline use. The program is built to push electrification and the building-envelope work that makes it perform. If a contractor tells you a straight gas-furnace replacement qualifies, verify it against the current Mass Save financing page before you bank on it.

Who qualifies, and the Municipal Light Plant wrinkle

You qualify if you're a Massachusetts homeowner with a current account from one of the Mass Save sponsors: Berkshire Gas, Cape Light Compact, Eversource, Liberty Utilities, National Grid, or Unitil. If one of those is your gas or electric provider, you're in the program's territory.

Now the local catch. About 40 Massachusetts towns get electricity from a Municipal Light Plant rather than an investor-owned utility, places like Belmont, Concord, Wellesley, and Reading. MLP electric customers generally can't tap Mass Save's electric incentives.

But the HEAT Loan has a carve-in the rebate side doesn't: Mass Save states that "municipal electric customers qualify if their home uses natural gas from a Mass Save Sponsor." So if you're on town electricity but heat with natural gas from National Grid, Eversource Gas, Berkshire Gas, Liberty, or Unitil, you can still get the HEAT Loan even though you're shut out of the heat pump rebate. That's a meaningful door for MLP-town homeowners that almost no other guide mentions, worth checking your gas bill before assuming you're excluded.

The home energy assessment comes first

For the big-ticket measures, you can't get the HEAT Loan without a free Mass Save Home Energy Assessment first. The assessment is required for whole-home heat pumps, partial heat pumps (the ones eligible for bonuses), windows, weatherization, and pre-weatherization barriers. For other measures it's optional but recommended.

There's a structural reason for the sequencing on heat pumps: Mass Save requires that "homes must be sufficiently weatherized prior to heat pump installation." A leaky, under-insulated house makes a heat pump work harder than it should in a New England winter. The assessment is what documents that your home clears the bar (or tells you the insulation work to do first, which the HEAT Loan can also finance). Either way, book the assessment early; scheduling can take a few weeks, and it's the gate to everything else.

How the loan stacks with rebates, and the federal credit that's gone

The HEAT Loan is designed to be used with the Mass Save rebate, not instead of it. The rebate knocks down the price; the loan finances what's left at 0%. For the actual rebate amounts, what a whole-home heat pump or a heat pump water heater gets back in 2026, go to our heat pump rebates guide, which keeps those numbers current.

What you should not count on for a 2026 install: the federal 25C Energy Efficient Home Improvement Credit (the one that gave up to $2,000 back on a heat pump). Per the IRS, that credit applies only to property "placed in service... before December 31, 2025." A system installed in 2026 does not qualify. Plenty of contractor pages still wave the $2,000 credit around, don't let it inflate your expected savings, and don't let a quote assume you'll claim it.

How to apply

The process runs in this order:

1. Schedule your free Mass Save Home Energy Assessment (required for heat pumps, weatherization, and windows). The assessor confirms eligibility and flags any weatherization you need first.
2. Get a quote from a Mass Save participating contractor using equipment on the Qualified Products List, that's what keeps the project loan-eligible.
3. Apply online at myheatloan.com (North Attleboro Electric customers use masssaveheatloan.com), then take your completed Authorization Form to a participating bank or credit union.
4. The lender approves you based on a standard credit review and closes the loan. Authorization letters don't stay valid forever, so apply promptly once you're ready to move.

Find a vetted installer who handles Mass Save paperwork on our Massachusetts HVAC directory, an experienced MA contractor will walk the assessment, rebate, and HEAT Loan steps with you rather than leaving you to file alone.

Frequently asked questions

Is the Mass Save HEAT Loan actually 0% interest? Yes. You borrow from a participating bank or credit union, and the Mass Save Program Sponsors buy the interest down to 0% for the loan's term. You repay only the principal. The lender still runs a credit check because a real bank is fronting the money.

Is the $25,000 limit per project or for life? It's a lifetime cap across all your measures combined, not per project. You can use the program more than once, but your loans together can't exceed $25,000. The cap has been $25,000 since January 1, 2025.

What's the repayment term? Up to 7 years, set by your lender at approval. There's no interest, so a longer term just means a smaller monthly payment.

What credit score do I need? Mass Save doesn't publish a program-wide minimum, each participating lender sets its own. They vary, so if your credit is borderline, ask the specific lender about their floor before you rely on the financing.

I'm in a Municipal Light Plant town. Can I still get it? Possibly. MLP electric customers generally can't get the Mass Save electric rebates, but you qualify for the HEAT Loan if your home heats with natural gas from a Mass Save gas sponsor. Check who supplies your gas. See our guide to MLP towns and Mass Save.

Do I have to do the home energy assessment first? For heat pumps, weatherization, and windows, yes, the free Mass Save assessment is required, partly to confirm your home is weatherized enough for a heat pump to perform. For some other measures it's optional but recommended.

Can I use the HEAT Loan and a rebate together? That's the intended play. The rebate reduces the price; the HEAT Loan finances the remaining balance at 0%. The two stack, just don't also count on the expired federal 25C tax credit for a 2026 install.