Efficiency Maine Qualified Heat Pumps 2026
HSPF-based QPL guide with brand-by-brand verification. Anti-dual-fuel policy, 80% sizing requirement, and income-tiered rebates up to $9,000 explained. Registered Vendor installation.
Quick Answer: What Heat Pumps Qualify for Efficiency Maine Rebates?
Efficiency Maine qualifies heat pumps using HSPF (not HSPF2): single indoor unit systems need HSPF ≥ 12.0, multi indoor unit systems need HSPF ≥ 10.0. The system must be sized for ≥80% of peak heating load, and dual-fuel setups are NOT eligible. Of the 12 brands NuWatt installs, 8 qualify for single-zone and all 12 qualify for multi-zone. Rebates are $1,000-$3,000 per unit (income-tiered) through Registered Vendors.
What Is the Efficiency Maine Qualified Product List?
The Efficiency Maine Rebate-Eligible Heat Pumps list is a proprietary spreadsheet maintained by Efficiency Maine Trust that identifies which heat pump models qualify for state rebates. Only systems on this list, installed by a Registered Vendor, qualify for rebates.
Unlike Mass Save (which uses ENERGY STAR 6.1 Cold-Climate with HSPF2 thresholds), Efficiency Maine uses HSPF per AHRI rating standards. This is one of the most important distinctions for homeowners comparing heat pump programs across New England states. A heat pump that qualifies in Massachusetts may not qualify in Maine for single-zone installations.
Efficiency Maine has installed over 100,000 heat pumps statewide since launching the program — one of the most successful state heat pump programs in the country. The QPL ensures that every rebated unit meets cold-climate performance standards appropriate for Maine's challenging winters.
Key QPL Facts
8 / 12
NuWatt Brands (Single-Zone)
12 / 12
NuWatt Brands (Multi-Zone)
$9,000
Max Rebate (Low-Income)
HSPF vs. HSPF2: Why Maine Uses a Different Standard
Efficiency Maine uses HSPF (Heating Seasonal Performance Factor) per AHRI ratings, while most other New England states use HSPF2 (DOE M1 test procedure). These are NOT interchangeable numbers.
| Metric | Standard | Description | Used By |
|---|---|---|---|
| HSPF | AHRI 210/240 | Original industry standard. Values are typically 15-25% higher than HSPF2 for the same unit. | Efficiency Maine, older program specs |
| HSPF2 | DOE M1 Test Procedure | Updated federal standard effective Jan 2023. More realistic test conditions produce lower numbers. | Mass Save, Energize CT, Clean Heat RI, federal ENERGY STAR |
Do Not Confuse HSPF and HSPF2
Approximate conversion: HSPF2 ≈ HSPF × 0.82-0.87. So Maine's HSPF ≥ 12.0 threshold for single-zone is roughly equivalent to HSPF2 ≥ 10.0, which is significantly HIGHER than Mass Save's HSPF2 ≥ 8.5 minimum.
Many heat pumps that qualify for Mass Save rebates in Massachusetts do NOT qualify for Efficiency Maine rebates in single-zone configurations. The HSPF ≥ 12.0 threshold is one of the strictest in the country for single-zone units.
QPL Qualification Criteria by Configuration
Efficiency Maine sets different HSPF thresholds for single indoor unit (1:1) and multi indoor unit (1:N) configurations. The single-zone threshold is significantly higher, filtering to only the top-tier cold-climate units.
| Configuration | HSPF Minimum | Approx. HSPF2 Equivalent | Notes |
|---|---|---|---|
| Single Indoor Unit (1:1) | ≥ 12 | ~≥ 10.0 | Highest threshold in New England. Filters to only premium cold-climate units. |
| Multi Indoor Unit (1:N) | ≥ 10 | ~≥ 8.3 | Lower threshold accommodates efficiency losses in multi-zone configurations. |
Source: Efficiency Maine Rebate-Eligible Heat Pumps spreadsheet. Thresholds use HSPF (AHRI 210/240), not HSPF2 (DOE M1). Last updated: 2026-03-15.
How Does This Compare to Other States?
| State | Metric | Single-Zone Min | Strictness |
|---|---|---|---|
| Maine | HSPF | ≥ 12.0 | Strictest |
| Massachusetts | HSPF2 | ≥ 8.5 | Moderate |
| Connecticut | HSPF2 | ≥ 8.1 | Lower |
Maine's HSPF ≥ 12.0 is roughly equivalent to HSPF2 ≥ 10.0 — significantly higher than Massachusetts' HSPF2 ≥ 8.5.
Anti-Dual-Fuel Policy: No Fossil Backup Allowed
Efficiency Maine does NOT allow dual-fuel installations (heat pump + fossil fuel backup) to qualify for rebates. The heat pump must be the sole heating system or supplement another electric heating source. This is unique in New England — Massachusetts, Connecticut, and Rhode Island all permit dual-fuel setups with approved integrated controls.
What Dual-Fuel Means (and Why It Voids Your Rebate)
- Cannot pair a heat pump with an oil boiler backup and still receive the rebate
- Cannot pair a heat pump with a propane furnace backup and still receive the rebate
- Cannot use the heat pump as "supplemental cooling only" — must handle heating load
- Electric resistance backup (baseboards, electric furnace) is acceptable
- Existing fossil fuel system can remain in place but must not be the primary heating source
Why Does Maine Have This Policy?
Maine designed this policy to ensure heat pumps genuinely displace fossil fuel heating, not just add cooling. With 60%+ of Maine homes heating with oil, the program aims for real fuel switching, not hybrid setups that still burn thousands of gallons of oil annually.
80% Peak Heating Load Sizing Requirement
The installed heat pump system must be sized to handle at least 80% of the home's peak heating load. This ensures the heat pump is the primary heating source, not a supplemental unit.
Efficiency Maine Registered Vendors perform a heating load assessment as part of the installation process. The load calculation considers home square footage, insulation levels, window area, infiltration rate, and Maine's design temperatures (ranging from -1°F in Portland to -18°F in Caribou).
Maine Design Temperatures by City
Portland
-1°F
Bangor
-7°F
Augusta
-7°F
Caribou
-18°F
Lewiston
-5°F
The heat pump must deliver ≥80% of rated capacity at these outdoor temperatures. Northern Maine cities like Caribou require units with exceptional cold-weather performance.
All 12 NuWatt Brands: Efficiency Maine QPL Status
8 of 12 brands qualify for single-zone installations (HSPF ≥ 12.0). All 12 brands qualify for multi-zone (HSPF ≥ 10.0). The grid below shows each brand's HSPF ratings and qualification status.
Mitsubishi
Full QPL14.2
Best HSPF
33.1
Best SEER
Sample qualifying models:
Mitsubishi Hyper-Heat H2i series comfortably exceeds both single-zone (HSPF 14.2) and multi-zone (HSPF 12.5+) thresholds. One of the safest picks for Efficiency Maine qualification. The FH series single-zone units are top performers.
Daikin
Full QPL13.5
Best HSPF
28.6
Best SEER
Sample qualifying models:
Daikin Aurora RXTA cold-climate series qualifies for single-zone (HSPF 13.5). Multi-zone MXL models also exceed the 10.0 threshold. The FIT ducted series may not meet single-zone HSPF requirements — verify specific model numbers.
Fujitsu
Full QPL15.4
Best HSPF
33.1
Best SEER
Sample qualifying models:
Fujitsu XLTH (Extra Low Temp Heating) series achieves the highest HSPF ratings of any brand NuWatt installs (15.4). Both single-zone Airstage AOUK units and multi-zone configurations comfortably qualify.
LG
Full QPL13.0
Best HSPF
24.0
Best SEER
Sample qualifying models:
LG LGRED cold-climate single-zone units (LSU-HXV3 series) meet HSPF 12.0+ for single-zone qualification. LGRED multi-zone outdoor units also qualify. The RED designation specifically indicates cold-climate rated.
Carrier
Multi-Zone Only11.5
Best HSPF
24.0
Best SEER
Sample qualifying models:
Carrier qualifies for multi-zone configurations (HSPF 10.0+) but most models fall short of the 12.0 single-zone threshold. If you need a single-zone unit in Maine, consider Mitsubishi, Fujitsu, or Daikin instead.
Carrier Greenspeed ducted systems achieve HSPF ~11.5, which falls below the 12.0 single-zone threshold. However, multi-zone mini-split configurations meet the 10.0 multi-zone threshold. The Infinity 25VNA series qualifies for multi-zone only.
Bosch
Full QPL12.5
Best HSPF
27.0
Best SEER
Sample qualifying models:
Bosch Climate 5000 ductless series qualifies for single-zone (HSPF 12.5). The IDS 2.0 ducted system falls below 12.0 for single-zone but qualifies for multi-zone. Choose the Climate 5000 for single-zone installations.
Lennox
Full QPL12.8
Best HSPF
27.0
Best SEER
Sample qualifying models:
Lennox MWLD cold-climate ductless series qualifies for single-zone (HSPF 12.8). Uses R-32 refrigerant and operates to -22 deg F. The XP25 ducted series qualifies for multi-zone only (HSPF ~11.0).
KEEN
Full QPL16.0
Best HSPF
38.0
Best SEER
Sample qualifying models:
KEEN (by ConnectM) achieves the highest HSPF of any brand (16.0 for flagship single-zone). Well above both single-zone and multi-zone thresholds. Newer brand with rapidly growing installer network.
TOSOT
Full QPL12.2
Best HSPF
26.0
Best SEER
Sample qualifying models:
TOSOT (by Gree) R-32 cold-climate single-zone units (TWH series) meet the 12.0 HSPF threshold. Multi-zone TM series also qualifies at 10.0+. Budget-friendly option that still meets Maine standards.
Rheem
Multi-Zone Only11.0
Best HSPF
22.0
Best SEER
Sample qualifying models:
Rheem qualifies for multi-zone only in Maine. The EcoNet ducted series and FPH ductless series meet the 10.0 multi-zone threshold but not the 12.0 single-zone threshold.
Rheem mini-split and ducted units achieve HSPF ~11.0, below the 12.0 single-zone threshold. Multi-zone configurations qualify at HSPF 10.0+. For single-zone installations in Maine, a different brand is recommended.
Goodman
Multi-Zone Only10.5
Best HSPF
20.0
Best SEER
Sample qualifying models:
Goodman qualifies for multi-zone ducted central installations only. No ductless mini-split offerings. The older GSZC18 series does not qualify at all.
Goodman GZV7 ducted central systems achieve HSPF ~10.5, well below the 12.0 single-zone threshold. Qualifies for multi-zone only. No ductless entries. For Maine single-zone, choose a cold-climate specialist brand.
York
Multi-Zone Only11.2
Best HSPF
22.0
Best SEER
Sample qualifying models:
York qualifies for multi-zone ducted configurations only. The HH8 series (R-454B) and YRAM series meet the 10.0 multi-zone minimum.
York ducted central systems achieve HSPF ~11.2, below the 12.0 single-zone threshold. Multi-zone configurations qualify at HSPF 10.0+. York is strong for commercial applications but limited for Maine residential single-zone.
Interactive QPL Model Checker
Use this tool to check if a specific NuWatt-installed brand qualifies for Efficiency Maine rebates. Select a brand to see its HSPF ratings, single-zone vs. multi-zone qualification, and sample models. For full verification, download the official QPL spreadsheet from Efficiency Maine.
Efficiency Maine QPL Model Checker
Check which NuWatt-installed brands qualify for Efficiency Maine rebates
Official Efficiency Maine QPL
For the most current qualification data, download the official Rebate-Eligible Heat Pumps spreadsheet from Efficiency Maine.
Download QPL Spreadsheet (.xlsx)The qualification data on this page reflects our analysis of the Efficiency Maine Rebate-Eligible Heat Pumps spreadsheet as of March 2026. The qualified product list is maintained by Efficiency Maine Trust and updated periodically. NuWatt Energy is not affiliated with Efficiency Maine Trust and does not control the QPL. For the most current and official qualification data, always verify at efficiencymaine.com. Specific rebate eligibility depends on your income level, home configuration, equipment selection, sizing compliance, and use of a Registered Vendor. HSPF ratings, model numbers, and qualification status may change without notice as manufacturers update their product lines and Efficiency Maine updates the QPL.
NuWatt is a Registered Efficiency Maine Vendor
We verify HSPF compliance, perform 80% sizing assessments, and process your rebate at point of sale.
Get a Free Heat Pump QuoteRegistered Vendor Requirement: Why Your Installer Matters
Having a QPL-qualifying heat pump is only part of the requirement. The installation must be performed by an Efficiency Maine Residential Registered Vendor. Without a Registered Vendor, you receive $0 in rebates — even if your equipment is on the QPL.
Efficiency Maine requires all heat pump rebate installations to be performed by a Residential Registered Vendor. This is similar to the Mass Save HPIN requirement — the vendor network ensures quality installations and proper sizing. The vendor handles rebate processing at point of sale, so the homeowner pays the reduced price upfront.
Vendor Requirements
- Licensed Maine HVAC contractor
- Completed Efficiency Maine vendor registration and training
- Maintains proper insurance and bonding
- Performs heating load assessment for 80% sizing verification
- Submits rebate documentation through Efficiency Maine portal
- Follows Efficiency Maine installation quality standards
- Does NOT install dual-fuel configurations for rebate-eligible projects
NuWatt Vendor Benefits
NuWatt Energy is a fully registered Efficiency Maine Residential Vendor.
- We verify every unit meets HSPF thresholds (12.0 single-zone / 10.0 multi-zone)
- We perform heating load assessments to confirm 80% sizing compliance
- We process your rebate at point of sale — you pay the reduced price
- We handle income verification paperwork for enhanced rebates ($2K/$3K tiers)
- We advise on single-zone vs. multi-zone to maximize rebate eligibility
- We never recommend dual-fuel setups that would void your rebate
Common Mistake: QPL Equipment + Unregistered Installer = $0 Rebate
Some contractors offer to install heat pumps at a lower price but are not Efficiency Maine Registered Vendors. In this case, you forfeit $1,000-$3,000 per unit in rebates. Always verify your installer is registered before signing a contract.
Efficiency Maine Rebate Amounts (2026)
Efficiency Maine uses a per-unit rebate structure (not per-ton like Mass Save). Rebates are income-tiered with three levels. Maximum 3 units per home. All tiers require QPL-qualifying equipment installed by a Registered Vendor. There is no federal residential tax credit in 2026.
Standard (Any Income)
$1,000/unit
Max: $3,000 (3 units)
None — all Maine residential electricity customers qualify
Moderate Income
$2,000/unit
Max: $6,000 (3 units)
Household income between 80-150% of Area Median Income (AMI)
Low Income
$3,000/unit
Max: $9,000 (3 units)
Household income at or below 80% of Area Median Income (AMI)
Point-of-Sale Rebate Processing
Unlike some state programs that require reimbursement after paying the full price, Efficiency Maine rebates are applied at point of sale through your Registered Vendor. You pay the reduced price on your invoice. NuWatt handles all rebate documentation so you see the discount immediately.
Full rebate guide with calculatorHow to Verify Your System on the Official QPL
While NuWatt handles QPL verification as part of every project, you can independently verify any heat pump on the official Efficiency Maine list.
Download the QPL Spreadsheet
Download the spreadsheet from efficiencymaine.com. The QPL is an Excel file (.xlsx) listing all eligible models.
Search by Outdoor Unit Model Number
Use Excel's search (Ctrl+F or Cmd+F) to find your outdoor unit model number. The spreadsheet includes manufacturer, model number, and HSPF rating for each entry.
Check the HSPF Rating Column
Verify the listed HSPF meets the threshold for your configuration: >= 12.0 for single indoor unit or >= 10.0 for multi indoor unit. Remember, this is HSPF (not HSPF2).
Confirm Configuration Type
The spreadsheet indicates whether each entry is for single or multi indoor unit configurations. Make sure the entry matches your planned installation type.
Verify with Your Registered Vendor
Your Efficiency Maine Registered Vendor should confirm QPL eligibility as part of the proposal. NuWatt verifies every model before ordering equipment.
Frequently Asked Questions
What heat pumps qualify for Efficiency Maine rebates?
Heat pumps must appear on the Efficiency Maine Rebate-Eligible Heat Pumps spreadsheet (QPL). For single indoor unit systems, the threshold is HSPF >= 12.0 per AHRI rating. For multi indoor unit systems, the threshold is HSPF >= 10.0. Note that Maine uses HSPF (not HSPF2), which is a different and generally higher number. The system must also be sized for at least 80% of the home's peak heating load, and dual-fuel setups (heat pump + fossil backup) are NOT eligible.
Why does Efficiency Maine use HSPF instead of HSPF2?
Efficiency Maine references HSPF per AHRI rating standards (AHRI 210/240), while most other New England states have transitioned to HSPF2 per the DOE M1 test procedure. HSPF values are typically 15-25% higher than HSPF2 for the same unit. Maine's HSPF >= 12.0 threshold for single-zone units is roughly equivalent to HSPF2 >= 10.0, which is significantly stricter than Mass Save's HSPF2 >= 8.5.
Can I get Efficiency Maine rebates with a dual-fuel setup?
No. Efficiency Maine does NOT allow dual-fuel installations (heat pump paired with a fossil fuel backup like oil or propane) to qualify for rebates. The heat pump must be the sole or primary heating system. This is a unique policy — Massachusetts, Connecticut, and Rhode Island all permit dual-fuel with approved integrated controls. Electric resistance backup (baseboards) is acceptable.
What is the 80% sizing requirement?
Efficiency Maine requires the heat pump system to be sized to handle at least 80% of the home's peak heating load. This ensures the heat pump is the primary heat source, not just a supplemental unit. Your Registered Vendor performs a heating load assessment considering your home's size, insulation, and Maine's design temperatures (from -1 deg F in Portland to -18 deg F in Caribou).
How much is the Efficiency Maine heat pump rebate in 2026?
Efficiency Maine offers three income-tiered rebate levels: $1,000 per unit for any income (up to $3,000 for 3 units), $2,000 per unit for moderate income households 80-150% AMI (up to $6,000), and $3,000 per unit for low-income households at or below 80% AMI (up to $9,000). Maximum 3 units per home. There is no federal residential tax credit in 2026.
Do all NuWatt brands qualify for Efficiency Maine rebates?
All 12 NuWatt brands qualify for multi-zone installations (HSPF >= 10.0). However, only 8 of 12 brands meet the stricter single-zone threshold (HSPF >= 12.0). Brands that qualify for single-zone include Mitsubishi, Fujitsu, Daikin, LG, Bosch, Lennox, KEEN, and TOSOT. Carrier, Rheem, Goodman, and York qualify for multi-zone only.
Which brands have the highest HSPF ratings?
Among NuWatt-installed brands, KEEN achieves the highest HSPF at 16.0, followed by Fujitsu at 15.4, Mitsubishi at 14.2, and Daikin at 13.5. These brands significantly exceed both the 12.0 single-zone and 10.0 multi-zone thresholds. Higher HSPF means more heat output per unit of electricity, which is especially important in Maine's cold winters.
What is an Efficiency Maine Registered Vendor?
A Registered Vendor is an Efficiency Maine-approved contractor authorized to install rebate-eligible heat pump systems. The vendor must be a licensed Maine HVAC contractor who has completed Efficiency Maine training, performs proper sizing assessments, and processes rebates at point of sale. NuWatt Energy is a fully registered Efficiency Maine Residential Vendor.
Do I pay the full price and get reimbursed for the rebate?
No. Efficiency Maine rebates are applied at point of sale through your Registered Vendor. You pay the reduced price upfront. This is different from some other state programs that require you to pay full price and submit for reimbursement. NuWatt handles all rebate processing so you see the discount on your invoice.
Can my existing oil boiler stay in the house if I install a heat pump?
The oil boiler can physically remain in the home, but it cannot serve as the primary or backup heating system if you want the Efficiency Maine rebate. The heat pump must handle at least 80% of peak heating load as a standalone system. Many homeowners keep the old boiler as an emergency-only backup but do not operate it regularly. Running both in a true dual-fuel configuration disqualifies you from the rebate.
Data Accuracy Disclaimer
The qualification data on this page reflects our analysis of the Efficiency Maine Rebate-Eligible Heat Pumps spreadsheet as of March 2026. The qualified product list is maintained by Efficiency Maine Trust and updated periodically. NuWatt Energy is not affiliated with Efficiency Maine Trust and does not control the QPL. For the most current and official qualification data, always verify at efficiencymaine.com. Specific rebate eligibility depends on your income level, home configuration, equipment selection, sizing compliance, and use of a Registered Vendor. HSPF ratings, model numbers, and qualification status may change without notice as manufacturers update their product lines and Efficiency Maine updates the QPL.
Get a Free Efficiency Maine Heat Pump Quote
NuWatt is a registered Efficiency Maine Vendor. We verify HSPF compliance, ensure 80% sizing, process your rebate at point of sale, and never recommend dual-fuel setups that would void your eligibility.
Free quote. No obligation. Registered Vendor installation guaranteed.
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