Score breakdown: 61/100
RatingPlate Score. Based on EIA energy prices, ENERGY STAR data, state rebate programs, and permit research. Not a government rating or purchasing recommendation. FAQ
Washington electricity is 21% below the national average. Here's what that means for heat pump operating costs.
Running cost in Washington
At Washington's 13.8¢/kWh electricity rate, the most efficient heat pump water heater saves an estimated $506 per year compared to a standard electric tank.
Washington electricity
13.8¢
per kWh (EIA, Jan 2026)
Best HP annual cost
$115
A. O. Smith HPTS-50-2
Electric resistance
$621
~4,500 kWh/yr baseline
Gas tank baseline
$300
~200 therms/yr
Colder inlet water (50°F annual average, 42°F in winter) means the heat pump works harder than DOE test conditions assume (58°F). Real-world efficiency will be slightly lower than rated UEF, and winter operating costs will be higher than the annual average.
Why Washington changes the call
01Energy costWashington electricity is 21% below the national average. That directly affects how much a heat pump saves compared to a standard electric tank.
02Climate impactIncoming water averages 50°F annually and drops to about 42°F in winter. Colder water means the heat pump works harder and real efficiency is slightly lower than rated.
03Available incentivesState and utility rebates can significantly change the payback period. Check what's currently available before finalizing your decision.
Rebates in Washington
Washington has 1 rebate program plus an active IRA HEAR point-of-sale rebate as of March 2026.
The federal $2,000 tax credit (IRA Section 25C) expired December 31, 2025. State and utility rebates listed below may still be available. Verify current status at the links provided.
PSE / Seattle City Light / Tacoma Power Rebates
$500-$1,000
Who: Puget Sound Energy / Seattle City Light / Tacoma Power / Avista
Eligibility: ENERGY STAR certified. Utility residential customer. UEF >= 2.0.
https://www.pse.com/rebates
IRA HEAR Rebate (Point-of-Sale)
Status: Check current program status in Washington. Up to $1,750 for income-qualified households.
This status was last verified on 2026-03-12 and may have changed. Check program website for current availability.
Install requirements in Washington
Code basis: Washington State Energy Code (based on IECC with amendments)
Heat pump preference in energy code
Washington's energy code uses a credit-based system that makes gas water heaters more difficult to install in new construction. Builders who install gas appliances must add compensating energy efficiency improvements. Not an outright mandate, but strongly incentivizes heat pump water heaters.
Seismic strapping
Required in western Washington and other seismic zones. Two straps, upper and lower third of the tank.
Electrical
Dedicated 240V, 30A circuit (most models). Some newer 120V plug-in models exist but most residential units require 240V. Check the unit's nameplate for exact requirements.
Condensate drain
Heat pump water heaters produce condensate during operation. A condensate drain line to an approved location (floor drain, condensate pump, or exterior) is required.
Air space
Approximately 700 cubic feet of surrounding air (roughly a 10x10x7-foot room). The heat pump extracts heat from surrounding air. Insufficient air volume reduces efficiency and can cause the unit to underperform. Some manufacturers allow ducting to supplement air supply in smaller spaces.
Noise
Heat pump water heaters produce operational noise similar to a window AC unit (45-55 dB). Consider placement away from bedrooms.
Best fits for Washington
A smaller set of representative fits using Washington's 13.8¢/kWh rate. Curated to show different trade-offs instead of listing every published model on every state page. See the full heat pump lineup.
Prefer to buy online? The 45-gallon Rheem PROPH50 T2 RH400-30 is a heat pump available on Amazon.
Common questions: Washington
Is a heat pump water heater worth it in Washington?
Yes. Washington scores B on RatingPlate's analysis, with estimated savings of $506 per year compared to a standard electric tank. Payback on the higher upfront cost is roughly 4.7 years before rebates.
What rebates are available for heat pump water heaters in Washington?
Washington has 1 utility or state rebate program plus an active IRA HEAR program. Check program pages for current amounts and eligibility, as funding can change.
How much does a heat pump water heater cost to run in Washington?
At Washington's electricity rate of 13.8 cents per kWh, the most efficient heat pump water heater costs about $115/yr to run. A standard electric tank costs about $621 per year.
Do I need a permit for a heat pump water heater in Washington?
Washington has 2 state-specific requirements: Heat pump preference in energy code, Seismic strapping. Most jurisdictions also require a standard plumbing or mechanical permit. Check with your local building department.
What is the payback period for a heat pump water heater in Washington?
Without rebates, the payback period in Washington is approximately 4.7 years based on $506 in annual savings versus a standard electric tank. With available rebates, payback could be significantly shorter.
Your next click
Sources
Electricity and natural gas rates: U.S. Energy Information Administration, residential sector (EIA, Jan 2026).
Rebate data compiled from state energy offices, utility program pages, DSIRE, and ENERGY STAR. Rebate amounts and eligibility change frequently. Verify at listed program URLs.
Inlet water temperatures estimated from NOAA climate normals using the Burch-Christensen mains water temperature model (NREL).
Model specifications from ENERGY STAR certified product data and manufacturer spec sheets.
Page generated July 12, 2026. Data freshness varies by source.
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