Boilers heat water that is then used to heat a home using a hot water or steam distribution system. The technology used for steam boilers is the same as for hot-water boilers, except that circulating pumps are not used in steam boilers. Boiler capacities range greatly, but they tend to be higher than furnace capacities.


Standards for residential boilers were included in the Energy Independence and Security Act (EISA) of 2007 and apply to gas-fired hot water boilers, gas-fired steam boilers, oil-fired hot water boilers, oil-fired steam boilers, and electric hot water boilers with an input of less than 300,000 Btu per hour manufactured after September 2012. The standards for each type of boiler include a requirement for annual fuel utilization efficiency (AFUE) and/or design requirements. AFUE refers to the portion of energy in the fuel that is converted to useful heat. The current standards for residential hot water boilers require a minimum efficiency of 82% for gas-fired equipment and 84% for oil-fired equipment.

In January 2016, DOE adopted new standards for boilers which will raise the minimum efficiency levels to 84% and 86% for gas-fired and oil-fired hot water boilers, respectively. DOE estimates that boilers meeting the new standards sold over 30 years will reduce national energy consumption by 0.16 quadrillion Btus and net savings of $0.35-1.2 billion for consumers. The new standards for residential boilers will take effect in 2021.


About 11 million US homes are heated with boilers using either gas or heating oil.  About 60% of homes heated by gas boilers and 80% of homes heated by oil boilers are in the Northeast. The new standards can be met by increasing the size of the heat exchanger. However, higher efficiency levels that would save almost five times as much energy as the standards in the final rule could be met using condensing technology. Condensing boilers extract additional heat by condensing the water vapor in the flue gases, resulting in efficiency levels of 90% or higher.

Projected Savings

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Federal Date States
Potential Effective Date of Updated Standard 2029
Updated DOE Standard Due 2024
Potential Effective Date of Updated Standard 2021
3rd Federal Standard Effective 2021
Updated DOE Standard Due 2016
Test Procedure - Last Revised - Standby/Off Mode 2016
3rd Federal Standard Adopted (DOE) 2016
2nd Federal Standard Effective 2012
Test Procedure - Last Revised - Standby/Off Mode 2010
2nd Federal Standard Adopted (Congress) 2007
2006 VT Standard Adopted
2005 MA Standard Adopted
2005 RI Standard Adopted
Test Procedure - Last Revised - Active Mode 1997
1st Federal Standard Effective 1992
1st Federal Standard Adopted (Congress) 1987
NAECA Initial Federal Legislation Enacted 1987

States not showing an effective date have an ongoing rulemaking process to determine standards.

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