Busting myths around tankless water heaters energy efficiency standards

The U.S. Senate voted to eliminate efficiency standards for gas tankless water heaters, increasing energy waste and health-harming pollution.

Energy efficiency


Updated

Yazan Aboushi | Used by permission

Water heaters are generally one of the biggest users of energy in our homes and provide hot water for showering, dishwashing, clothes washing, and other household needs. Improving the efficiency of these appliances can deliver big energy savings, but common-sense rules that reduce energy waste in gas tankless water heaters were recently scrapped by Congress.

What is a gas tankless water heater? 

Tankless water heaters heat water instantaneously without the use of a storage tank. When a hot water faucet is turned on, cold water flows through a heat exchanger in the unit, and a gas burner heats the water.

Kevin T Murray via Flickr | CC-BY-2.0
Tankless water heaters, also referred to as demand-type or instantaneous water heaters don't have a storage tank. Instead they heat water as it is needed.

What happened with the gas tankless water heater standard? 

In December 2024, the U.S. Department of Energy (DOE) finalized new efficiency standards for gas tankless water heaters, complementing an earlier final rule strengthening standards for other water heater types. 

In February 2025, the U.S. House of Representatives voted on a resolution that would repeal the standards and prevent DOE from ever setting efficiency standards for these products in the future. 

The U.S. Senate took up the resolution on Thursday, April 10th and passed it by a vote of 53-44.  Two Democrats from Georgia joined all Republican members of the senate in voting to do away with efficiency standards for gas-powered tankless water heaters. 

Efficiency advocates including the Appliance Standards Awareness Project and Environment America opposed the rollback. In the weeks leading up to the vote, advocates worked to help lawmakers separate fact from fiction when it comes to what is at stake with these standards.

Myths & facts around the tankless gas water heater standard

Myth #1: Efficiency standards are effectively a ban on gas-powered water heaters.

Fact: Water heater efficiency standards do not ban gas-powered water heaters. Instead, they make sure that water heaters that burn gas incorporate the latest cost-effective technology to make sure the water heaters aren’t wasting energy.

Myth #2: Efficiency standards for gas tankless water heaters will harm consumers.

Fact: Gas tankless water heaters mean less pollution and lower overall energy costs for consumers. 

The Department of Energy (DOE) estimates that the standards for gas tankless water heaters will reduce energy waste and pollution. DOE estimates that the updated standard lowers the total costs for households that choose these products by an average of $112 over the life of the appliance.

Gas-powered tankless water heaters are a relatively niche product representing only 12% of the total water heater market and are disproportionately used by high-income households.

Myth #3: Unlike electric water heaters, gas tankless water heaters can still provide hot water when the power goes out.

Fact: Gas tankless water heaters cannot operate if the power goes out, because they use electronic ignition systems.

What other kinds of water heaters are available?

Consumers in the market for a new water heater will find many options.  There are two main types of residential water heaters: storage-type – which are most common in the U.S. – and instantaneous or on-demand water heaters. Residential water heaters can be powered by a number of fuels including electricity, gas, propane or fuel oil. Some water heaters use solar power. The Department of Energy offers resources to help consumers get the right water heater for their situation.

Brian Cantoni | CC-BY-2.0
Conventional storage water heaters, such as the one pictured above, remain the most popular type of water heating system in U.S. homes.

What water heaters are most efficient?

Generally electric water heaters that incorporate heat pump technology are the most energy-efficient option. Heat pump water heaters that earn the ENERGY STAR label are up to 4 times more energy-efficient and use 70 percent less energy than a standard electric model.

“American families will be exposed to more health-harming pollution because the Senate sided with a group of gas utilities and one specific manufacturer,” said Johanna Neumann, Senior Director of the Campaign for 100% Renewable Energy at Environment America. “With this decision, outdated energy-wasting technologies will remain on the market, increasing air pollution and needlessly raising utility bills.”

Efficiency standards embody the phrase "waste not, want not" and benefit all American families by making sure we’re using energy wisely. Johanna Neumann
Senior Director, Campaign for 100% Renewable Energy

Add your voice to stand up for energy efficiency.

Although the vote on gas tankless water heaters is done, our elected officials in Washington D.C. will decide the future of additional energy efficiency rules in the future, and if you want them to support energy-saving policies, they need to hear from you. You can email your members of Congress and urge them to stand up for energy efficiency by taking action below.

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Authors

Johanna Neumann

Senior Director, Campaign for 100% Renewable Energy, Environment America

Johanna directs strategy and staff for Environment America's energy campaigns at the local, state and national level. In her prior positions, she led the campaign to ban smoking in all Maryland workplaces, helped stop the construction of a new nuclear reactor on the shores of the Chesapeake Bay and helped build the support necessary to pass the EmPOWER Maryland Act, which set a goal of reducing the state’s per capita electricity use by 15 percent. She also currently serves on the board of Community Action Works. Johanna lives in Amherst, Massachusetts, with her family, where she enjoys growing dahlias, biking and the occasional game of goaltimate. 

Abe Scarr

State Director, Illinois PIRG; Energy and Utilities Program Director, PIRG

Abe Scarr is the director of Illinois PIRG and is the PIRG Energy and Utilities Program Director. He is a lead advocate in the Illinois Capitol and in the media for stronger consumer protections, utility accountability, and good government. In 2017, Abe led a coalition to pass legislation to implement automatic voter registration in Illinois, winning unanimous support in the Illinois General Assembly for the bill. He has co-authored multiple in-depth reports on Illinois utility policy and leads coalition campaigns to reform the Peoples Gas pipe replacement program. As PIRG's Energy and Utilities Program Director, Abe supports PIRG energy and utility campaigns across the country and leads the national Gas Stoves coalition. He also serves as a board member for the Consumer Federation of America. Abe lives in Chicago, where he enjoys biking, cooking and tending his garden.

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