The $450 rebate most Montgomery County homeowners miss.

Washington Gas offers Maryland customers up to $450 for installing an Energy Star certified tankless water heater. Here's the complete 2026 guide to eligibility and how to apply.

Updated May 2026Washington Gas programStackable with federal5 min read

Washington Gas — the natural gas utility serving most of Montgomery County — runs an energy efficiency rebate program funded through the EmPOWER Maryland Act. For tankless water heaters, the rebate is worth up to $450 for Maryland customers in 2026. Combine it with other available incentives and you can stack up to $1,400 in total savings.

Who qualifies

You qualify for the Washington Gas tankless rebate if:

  • You are a Washington Gas Maryland residential customer (have an active natural gas account)
  • You install an Energy Star certified tankless water heater (most Rinnai, Navien, and Rheem units qualify)
  • The installation is done by a contractor in the Washington Gas Home Energy Savings Network
  • The unit meets the minimum Uniform Energy Factor (UEF) threshold — typically 0.87 or higher for the standard rebate
  • You file the rebate paperwork within 90 days of installation

That last point is critical — the 90-day window is strictly enforced, and many homeowners miss it.

How much you'll actually get

The rebate amount depends on the unit's efficiency rating:

UEF efficiencyRebate amountExample units
0.87 – 0.92 UEF$300Standard non-condensing tankless
0.93 – 0.95 UEF$400Most condensing tankless
0.96+ UEF$450Top-tier condensing (Navien NPE-A2, Rinnai RX)

Check the unit's Energy Star certification for its exact UEF rating before purchasing.

How to apply

Step 1 — Confirm contractor eligibility

Before hiring a contractor, confirm they're in the Washington Gas Home Energy Savings Network. A DIY install or work by a non-approved contractor disqualifies you from the rebate entirely.

Step 2 — Gather your documentation

After installation, you'll need:

  • Your Washington Gas utility account number
  • The unit's serial number and model number
  • The unit's UEF rating (from the Energy Star certification)
  • Your contractor's signed invoice showing the installation date and cost

Step 3 — Submit through the portal

Go to the Washington Gas Smart Savings portal and complete the online rebate application. Upload your documentation and submit within 90 days of your installation date.

Step 4 — Wait for processing

Washington Gas typically processes applications within 4-6 weeks. The rebate is paid as a physical check mailed to your address on file. Total time from installation to check: 6-8 weeks.

Stackable with three other rebates

The Washington Gas rebate is just one of four incentives you can stack for a Montgomery County tankless install:

  • Washington Gas rebate: Up to $450
  • Manufacturer rebate: Additional $100 on select Rinnai/Navien models
  • Federal tax credit (IRS 25C): Up to $600 (30% of project cost, capped)
  • Montgomery County property tax credit: Up to $250 for energy efficiency improvements

Total stackable: up to $1,400. See our full rebates guide for details on each program and how to apply.

Common mistakes to avoid

Mistake 1 — Using a non-approved contractor

Washington Gas explicitly requires the install be done by a contractor in their approved network. Even if you install a qualifying unit, you won't be eligible for the rebate if your contractor isn't in the network. Ask before you hire.

Mistake 2 — Missing the 90-day deadline

The 90-day filing window starts at installation completion. Mark your calendar and submit your application as soon as you have your documentation together. Late applications are rejected.

Mistake 3 — Not claiming the federal credit too

The $450 Washington Gas rebate gets homeowners' attention, but many forget to also claim the federal 25C tax credit worth up to $600. That's a separate form filed with your taxes — don't leave it on the table.

Mistake 4 — Forgetting about the county credit

The $250 Montgomery County property tax credit is the least-known of the four available incentives. It applies to energy efficiency improvements including water heating upgrades.

If you've already missed the deadline

If you installed a tankless heater and missed the 90-day Washington Gas window, you may still be able to claim:

  • Federal tax credit: Claim for the tax year of installation, even if you haven't filed yet
  • Montgomery County credit: Check if you're within the annual application window
  • Manufacturer rebate: Usually closed after the initial window, but check the portals

The Washington Gas rebate, unfortunately, cannot be claimed after the 90-day window closes.

Apply now

Ready to claim your rebate? Visit the Washington Gas Smart Savings portal:

Washington Gas rebate portal