Commercial Water Heaters


Commercial water heaters include a wide range of equipment that heats potable water for purposes other than space heating. Businesses with commercial water heaters range from office buildings, which typically use very little hot water, to restaurants, which may use large volumes. Although there are electric and oil-fired commercial water heaters, gas-fired equipment accounts for most of the energy consumption of this product category


The Energy Policy and Conservation Act of 1975 (EPCA) directs the U.S. Department of Energy (DOE) to establish energy conservation standards for certain commercial and industrial equipment, including commercial water heaters. EPCA requires that each time the American Society of Heating, Refrigerating and Air-Conditioning Engineers, Inc. (ASHRAE) Standard 90.1 is amended, DOE must assess whether there is a need to update the uniform national energy conservation standards for the same equipment covered under EPCA. ASHRAE officially released an amended version of Standard 90.1-2013 on October 9, 2013, thereby triggering DOE's related obligations under EPCA.

In May 2016, DOE proposed new standards for commercial water heating equipment. The proposed standards include modest decreases in stand-by losses for all hot water storage tanks. DOE also proposes significant improvements to gas-fired storage and instantaneous water heaters, from 80% to either 94% or 95% minimum thermal efficiency depending upon equipment type. These thermal efficiency levels would require commercial hot water heater manufacturers to use heat reclamation technology to condense water vapor from combustion exhaust gases.

Residential-duty commercial water heaters are designed to supply hot water to businesses with hot water consumption patterns similar to residences. DOE proposes to subject this class of commercial water heaters to separate efficiency standards. The proposed standards for gas-fired residential duty commercial water heaters would also require exhaust gas vapor condensation technology.

According to DOE estimates, the 2016 commercial water heater standards will lower national energy usage by 1.8 quadrillion Btus, save consumers between $2.3 and $6.8 billion, and reduce CO2 emissions by 98 million metric tons over 30 years of sales.

The final rule was not published. The gas industry filed a petition in October 2018 and subsequently DOE published a request for more information. 


Technology options for improving efficiency include the use of condensing technology for gas-fired water heaters and improved insulation for tanks on all storage models.

The proposed 2016 commercial water heater standards would also bring the efficiency requirements for gas-fired residential duty commercial water heaters in line with the efficiency standard for gas-fire residential water heaters. However, there would be no  electric commercial water heater equivalent to the residential electric water heater efficiency standard requirement of heat pump levels of efficiency for tanks over 55 gallons.


Federal Date States
Potential Effective Date of Updated Standard 2021
Updated DOE Standard Due 2018
Test Procedure - Last Revised - Active Mode 2004
2nd Federal Standard Effective 2003
2nd Federal Standard Adopted (DOE) 2001
1st Federal Standard Effective 1994
EPACT Initial Federal Legislation Enacted 1992
1st Federal Standard Adopted (Congress) 1992

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