Mass Save heat pump water heaters rebates
For HVAC contractors filing on behalf of a residential customer.
Mass Save pays a flat rebate per heat pump water heater, normally applied instantly at the point of sale through a participating distributor, retailer or the program's online marketplace. A mail-in form exists only for equipment bought without the instant rebate applied — the two cannot both be claimed for the same unit.
3 open questions on this pathway
The official documents disagree or are silent on the points below. We show them rather than picking a reading, and this is why this pathway is not check-supported.
- Whether the UEF thresholds are inclusive. The form writes the thresholds as UEF > 3.30 and UEF > 2.20, strictly greater. The program page writes them as UEF 3.30 and UEF 2.20, which reads as at-or-above. A unit rated exactly 3.30 qualifies under one reading and not the other.
- Filing deadline. The program page says documentation must be RECEIVED BY 28 February 2027; the form's Terms and Conditions say applications must be POSTMARKED BY that date. This is the same contradiction found in the air source, ground source and Basic forms — four of four.
- Building size. The program page says equipment must be installed in a residential home with 1–4 units. The rebate form's housing type field nonetheless offers a '5+ unit building' checkbox alongside single-family and 2–4 unit. Confirm whether 5+ unit buildings are eligible before advising on one.
Rebate amounts
| What | Value in this edition | Source |
|---|---|---|
| Heat pump water heaterRequires ENERGY STAR certification with a Uniform Energy Factor above 3.30. | $750 per unit | S7, S8 |
| Heat pump water heater, 120 volt / 15 amp circuitLower efficiency threshold: UEF above 2.20. | $750 per unit | S7, S8 |
| Split-system heat pump water heaterUEF above 2.20. | $1,500 per system | S7, S8 |
| Limit | One rebate per electric or natural gas meter | S7, S8 |
| Ceiling | Rebate may not exceed the purchase price | S7, S8 |
| Instant rebate and mail-in cannot both be claimed | If the instant rebate was applied at a participating retailer or distributor, the mail-in rebate cannot be redeemed for that unit. | S8 |
| Whether the UEF thresholds are inclusiveThe form writes the thresholds as UEF > 3.30 and UEF > 2.20, strictly greater. The program page writes them as UEF 3.30 and UEF 2.20, which reads as at-or-above. A unit rated exactly 3.30 qualifies under one reading and not the other. | Unresolved Unresolved | S7, S8 |
Dates and deadlines
| What | Value in this edition | Source |
|---|---|---|
| Purchase and installation window | 1 January 2026 to 31 December 2026, inclusive | S7, S8 |
| Filing deadlineThe program page says documentation must be RECEIVED BY 28 February 2027; the form's Terms and Conditions say applications must be POSTMARKED BY that date. This is the same contradiction found in the air source, ground source and Basic forms — four of four. | Unresolved 28 February 2027 — but the rule for meeting it is unresolved | S7, S8 |
| Payment processing | 6–8 weeks after an approved submission | S8 |
Eligibility
| What | Value in this edition | Source |
|---|---|---|
| Sponsor | Residential customer in Massachusetts where Berkshire Gas, Cape Light Compact, Eversource, Liberty, National Grid or Unitil is the Sponsor. Municipal electric customers qualify if they are a natural gas heating customer of a Sponsor. | S7, S8 |
| Installer | A licensed plumber. Unlike the heat pump pathways, there is no Heat Pump Installer Network requirement and no HPIN Company ID on the form. | S7, S8 |
| Equipment | New, ENERGY STAR certified, replacing an existing electric resistance, propane, natural gas or oil water heater. | S7 |
| New construction | Allowed, provided the project is not enrolled in the Mass Save New Construction program. This is the opposite of the heat pump pathways, which exclude new construction outright. | S7, S8 |
| Building sizeThe program page says equipment must be installed in a residential home with 1–4 units. The rebate form's housing type field nonetheless offers a '5+ unit building' checkbox alongside single-family and 2–4 unit. Confirm whether 5+ unit buildings are eligible before advising on one. | Unresolved Unresolved | S7, S8 |
| Combination | Not combinable with any other utility or efficiency-provider offer for the same equipment, except the HEAT Loan. | S7, S8 |
Document checklist
| Document | What it must show | Source |
|---|---|---|
| Completed and signed rebate form | Only needed when no instant rebate was applied at purchase. Customer signature only. | S8 |
| Dated work order, invoice or sales receipt | Showing equipment manufacturer and model number, and the heat pump water heater purchase cost. | S8 |
| Proof of payment | Accompanying the receipt. | S8 |
Equipment evidence
The form captures manufacturer, model number and install date — no AHRI reference and no capacity, because the rebate is a flat amount per unit rather than a per-ton calculation. Which of the three rate tiers applies turns on the ENERGY STAR listing and whether the unit is a split system.
Installer requirement
Installation by a licensed plumber. For the instant-rebate route the plumber buys the unit from a participating distributor and the discount is applied at purchase.
Where the application goes
Most units are rebated instantly at a participating distributor, at Home Depot or Lowe's via MassSave.com/Instant, or through the Mass Save heat pump water heater online marketplace. Only when no instant rebate was applied does the contractor file — online at MassSave.com/Savings, or by mail to Mass Save Residential Heating and Cooling Program, 1337 Massachusetts Ave, PO Box #228, Arlington, MA 02476.
Sources
Every fact above cites one of these by id. Each was retrieved and hashed on the date shown; we link the official document rather than restating it.
| Id | Document | Retrieved | SHA-256 |
|---|---|---|---|
| S7 | Mass Save heat pump water heaters program page | 2026-09-07 | 7ee878b9e630bad2… |
| S8 | 2026 Residential Heat Pump Water Heater Rebate FormRevision 0078_HPWH_12.25 | 2026-09-07 | e8a82941c90fbb7e… |
Administered by
The Sponsors of Mass Save (Berkshire Gas, Cape Light Compact, Eversource, Liberty, National Grid, Unitil)
Where it applies
Massachusetts. Customers of Berkshire Gas, Cape Light Compact, Eversource, Liberty, National Grid, Unitil.
Confirm the customer's actual sponsor. A ZIP code does not establish service territory.
Official source
Mass Save official program page
Last confirmed to resolve 2026-09-07. The program administrator decides eligibility and payment.
Read the requirements and checklist
RebateBench is in private pilot and no pathway is packet supported yet. If this is a program you file, we would like to verify it with you.
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