Stack up to $1,400 in rebates.

Montgomery County homeowners can claim four separate rebates when installing a tankless water heater. Here's how each one works and how to apply.

4 stackable rebatesWashington Gas eligibleEnergy Star certifiedUpdated 2026
Stackable$1,400

That's the maximum stackable rebate for a qualifying tankless install in Montgomery County — when you combine all four available incentives.

The four rebates

Every Montgomery County incentive, explained clearly.

These are the four rebates that stack for a natural-gas tankless install in 2026. Click the links below each to go directly to the application portal.

Washington Gas · Maryland
up to$450

Tankless water heater rebate

Washington Gas offers rebates on ENERGY STAR certified tankless water heaters. For Maryland customers, rebates range from $300–$450 depending on the unit's efficiency rating (UEF). Higher-efficiency condensing units qualify for the full $450.

How to apply Must be a Washington Gas Maryland customer · Unit must be Energy Star certified · Installation by an approved contractor in their network · File within 90 days of installation via the portal below.
Federal · IRS Form 5695
up to$600

Energy Efficient Home Improvement Credit (25C)

Under the federal Energy Efficient Home Improvement Credit, homeowners can claim 30% of the project cost (unit + installation labor) on qualifying Energy Star certified gas tankless water heaters, up to a $600 annual cap.

How to apply Energy Star certified unit with UEF ≥ 0.95 · Must be your primary residence · Claim on your federal tax return for the year of installation using Form 5695 · Keep your invoice and manufacturer certification.
Manufacturer · MD & VA
extra$100

Manufacturer rebates

Rinnai and Navien both offer manufacturer rebates on select models for Maryland and Virginia customers. These stack with the Washington Gas rebate for additional savings on the equipment itself.

How to apply Check the manufacturer portals below for current eligible models · Typically requires registration within 30–60 days of purchase · Need invoice and serial number documentation.
Montgomery County · Department of Finance
up to$250

Energy Conservation Devices property tax credit

Montgomery County offers property tax credits for energy efficiency improvements including water heating upgrades. Applications are processed in order received; annual program funding is limited.

How to apply Must be a Montgomery County property · Primary residence · Submit application to Dept. of Finance · Include documentation of installed equipment and costs.
Worked example

How the rebates stack together.

Here's an example of how the four rebates might stack for a typical Montgomery County tankless install.

Example · Typical 4BR home
Condensing tankless install · Rockville, MD
Typical installed cost (unit + labor + permit)$5,000
Washington Gas rebate (0.96+ UEF unit)−$450
Manufacturer rebate (Navien or Rinnai)−$100
Federal tax credit (30% × $5,000, capped at $600)−$600
Montgomery County property tax credit−$250
Net cost after all rebates$3,600
Note: Actual rebate amounts depend on the specific unit installed and your eligibility. The federal credit is claimed on your tax return; other rebates are typically received as checks or invoice credits.
Filing tips

How to claim each rebate.

Each rebate has its own application process and timeline. Here's what you need to know.

Within 90 days

Washington Gas rebate

Apply through the Washington Gas Smart Savings portal within 90 days of installation. You'll need your utility account number, the unit's serial number and UEF rating, and your contractor's invoice. Ask your contractor if they're in the Washington Gas approved network — this is required for eligibility.

Within 30–60 days

Manufacturer rebate

Check Navien or Rinnai's rebate portal for current offers in Maryland. Register your unit online with your serial number and proof of purchase. Rebates are typically mailed as checks within 6–8 weeks of approval.

At tax time

Federal tax credit (Form 5695)

Claim the credit when you file your federal taxes for the year of installation. You'll need IRS Form 5695 and documentation including your invoice and the manufacturer's Energy Star certification. Keep these records — the IRS may request them.

Before county deadline

Montgomery County tax credit

Apply through the Montgomery County Department of Finance. Include documentation of your energy efficiency improvement and costs. The program has annual funding limits, so apply early in the fiscal year if possible.

Other programs

Other programs worth knowing about.

If you're considering going all-electric or weatherizing your whole home, these Montgomery County programs may offer additional savings.

Pepco · Up to $1,600

Heat pump water heater rebate

If you're willing to switch to all-electric, Pepco offers significant rebates on Energy Star certified heat pump water heaters. Best fit for homes converting away from gas or with basement space for the heat pump footprint.

MD · Up to $15,000

Home Performance with ENERGY STAR

BGE, Pepco, and Delmarva Power run a statewide electrification program offering up to $15,000 for homeowners switching from fossil fuels to heat pumps (HVAC or water heater). Requires an energy audit first.

MD · Low-income households

Maryland Weatherization Assistance

For income-eligible Maryland households, the Weatherization Assistance Program provides no-cost insulation, air sealing, and hot water heater improvements. Family of 4 qualifies under ~$94K household income.