Water Heaters


Consumer water heaters are used to provide hot water for showering, dishwashing, clothes washing, and other household needs. Residential water heaters can use electricity, natural gas, propane or fuel oil. There are two main types of residential water heaters: storage-type and instantaneous.


The current standards for residential water heaters took effect in 2015. The efficiency requirements vary depending on the type of water heater and the rated storage volume. For storage water heaters with a volume greater than 55 gallons, the standards effectively require heat pump technology for electric products and condensing technology for gas products. 

In 2023, DOE proposed amended water heater efficiency standards that would shift most new electric storage models to more efficient heat pump technology, which cuts energy use in half. For gas-fired water heaters, the proposed standards would reduce energy use by 9-13%, depending on the type of model. The proposed standards are generally similar to recommendations submitted to DOE by a multistakeholder coalition of two of the largest water heater manufacturers (Bradford White and Rheem), energy efficiency organizations (American Council for an Energy-Efficient Economy, Appliance Standards Awareness Project, and Northwest Energy Efficiency Alliance), environmental advocates (Natural Resources Defense Council), and consumer advocates (Consumer Federation of America).

*Uniform energy factor (UEF) describes the energy efficiency performance of a water heater.


As of 2020, residential water heating represented 18% percent of total annual household site energy consumption in the U.S. About 48% of households have natural gas water heaters, while 46% have electric and slightly more than 5% burn propane or oil.

Typical heat pump water heaters on the market today have UEFs above 3.0, while conventional electric resistance water heaters have UEFs below 1.0. Condensing gas water heaters can reduce energy consumption by up to about 31% compared to conventional gas units. 

Savings through what year?: 2043
Energy saved (quads): 2.58
CO2 savings (million metric tons): 154
Net present value savings ($billion) 3% discount rate: 8.67
Net present value savings ($billion) 7% discount rate: 1.39

Fact Sheets


ASAP Press Releases



Federal Date States
Potential Effective Date of Updated Standard 2023
Updated DOE Standard Due 2018
3rd Federal Standard Effective 2015
Test Procedure - Last Revised - Standby/Off Mode 2012
Initial Federal Legislation Enacted 2012
3rd Federal Standard Adopted (DOE) 2010
2nd Federal Standard Effective 2004
2nd Federal Standard Adopted (DOE) 2001
Test Procedure - Last Revised - Active Mode 2001
1st Federal Standard Effective 1990
1st Federal Standard Adopted (Congress) 1987
NAECA Initial Federal Legislation Enacted 1987

Timeline reflects state standards from 2001 to present; federal standards from inception to present.