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Residential Water Heaters

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Manufacturers have been required to comply with the Department of Energy (DOE) energy conservation standards for residential water heaters since 1990. Residential water heaters are products that utilize oil, gas, or electricity to heat potable water for use upon demand for activities such as washing dishes or clothes, or bathing. Residential water heaters include storage type units that store heated water in an insulated tank and instantaneous type units that heat water on demand.

The standard mandatory in 1990 will save approximately 3.2 quads of energy and result in approximately $34.8 billion in energy bill savings for products shipped from 1990-2019. The standard will avoid about 180 million metric tons of carbon dioxide emissions, equivalent to the annual greenhouse gas emissions of about 35.3 million automobiles.

The standard mandatory in 2004 will save approximately 6 quads of energy and result in approximately $70.6 billion in energy bill savings for products shipped from 2004-2033. The standard will avoid about 316.8 million metric tons of carbon dioxide emissions, equivalent to the annual greenhouse gas emissions of about 62.1 million automobiles.

Standards mandatory in 2015 will save approximately 3.3 quads of energy and result in approximately $63 billion in energy bill savings for products shipped from 2015-2044. The standard will avoid about 172.5 million metric tons of carbon dioxide emissions, equivalent to the annual greenhouse gas emissions of about 33.8 million automobiles.

Recent Updates

DOE has published correction notice regarding grid-enabled water heaters. 80 FR 50757 (August 21, 2015)

DOE has published a final rule regarding grid-enabled water heaters. 80 FR 48004 (August 11, 2015).

Standards for Residential Water Heaters

The following content summarizes the energy factor requirements for residential water heaters. The text is not an official reproduction of the Code of Federal Regulations and should not be used for legal research or citation.

Current Standard

Gas-fired ( less than equal to sign 75 kBtu/h input capacity), oil-fired ( 105 kBtu/h input capacity), electric ( 12 kW input capacity), and tabletop ( 12 kW input capacity) storage water heaters as well as instantaneous gas-fired (<200 kBtu/h input capacity) and electric ( 12 kW input capacity) water heaters manufactured and distributed in commerce, as defined by 42 U.S.C. 6291(16), must meet the energy conservation standards specified in the Code of Federal Regulations, 10 CFR 430.32(d) as of January 20, 2004. This information is also available in the Electronic Code of Federal Regulations.

Table 1. Energy Conservation Standards for Residential Water Heaters
Product Class	Rated Storage Volume	Energy Factor
Gas-fired Water Heater	20 gal and 100 gal	0.67 – (0.0019*V_s)
Oil-fired Water Heater	50 gal	0.59 – (0.0019*V_s)
Electric Water Heater	20 gal and 120 gal	0.97 – (0.00132*V_s)
Tabletop Water Heater	20 gal and 100 gal	0.93 – (0.00132*V_s)
Instantaneous Gas-fired Water Heater	< 2 gal	0.62 – (0.0019*V_s)
Instantaneous Electric Water Heater	< 2 gal	0.93 – (0.00132*V_s)

V_s: Rated Storage Volume – the water storage capacity of a water heater (in gallons).

Final Rule: Standards, Federal Register, 66 FR 4474 (January 17, 2001)
Technical Support Document
Docket No.EE-2006-STD-0129 contains notices, public comments, public meeting transcripts, and supporting documents

For further guidance or to submit questions related to the implementation of this standard, visit the Guidance and Frequently Asked Questions page.

Amended Standard

(1) Water heaters. The energy factor of water heaters shall not be less than the following for products manufactured on or after the indicated dates.

Table 2. Amended Energy Conservation Standards for Residential Water Heaters
Product class	Storage Volume	Energy Factor as of January 20, 2004	Energy Factor as of April 16, 2015
Gas-fired Storage Water Heater	20 gallons and 100 gallons	0.67-(0.0019 × Rated Storage Volume in gallons)	For tanks with a Rated Storage Volume at or below 55 gallons: EF = 0.675-(0.0015 × Rated Storage Volume in gallons). For tanks with a Rated Storage Volume above 55 gallons: EF = 0.8012-(0.00078 × Rated Storage Volume in gallons).
Oil-fired Storage Water Heater	50 gallons	0.59-(0.0019 × Rated Storage Volume in gallons)	EF = 0.68-(0.0019 × Rated Storage Volume in gallons).
Electric Storage Water Heater	20 gallons and 120 gallons	0.97-(0.00132 × Rated Storage Volume in gallons)	For tanks with a Rated Storage Volume at or below 55 gallons: EF = 0.960-(0.0003 × Rated Storage Volume in gallons). For tanks with a Rated Storage Volume above 55 gallons: EF = 2.057-(0.00113 × Rated Storage Volume in gallons).
Tabletop Water Heater	20 gallons and 120 gallons	0.93-(0.00132 × Rated Storage Volume in gallons)	EF = 0.93-(0.00132 × Rated Storage Volume in gallons).
Instantaneous Gas-fired Water Heater	< 2 gallons	0.62-(0.0019 × Rated Storage Volume in gallons)	EF = 0.82-(0.0019 × Rated Storage Volume in gallons).
Instantaneous Electric Water Heater	< 2 gallons	0.93-(0.00132 × Rated Storage Volume in gallons)	EF = 0.93-(0.00132 × Rated Storage Volume in gallons).

(2) Grid-enabled water heaters. Exclusions: The energy conservation standards shown in this paragraph do not apply to the following types of water heaters: gas-fired, oil-fired, and electric water heaters at or above 2 gallons storage volume and below 20 gallons storage volume; gas-fired water heaters above 100 gallons storage volume; oil-fired water heaters above 50 gallons storage volume; electric water heaters above 120 gallons storage volume; gas-fired instantaneous water heaters at or below 50,000 Btu/h; and grid-enabled water heaters.

(i) Energy factor -- The energy factor of grid-enabled water heaters, as of April 30, 2015, shall not be less than 1.06 –(0.00168 × Rated Storage Volume in gallons).

NOTE: The Rated Storage Volume equals the water storage capacity of a water heater, in gallons, as certified by the manufacturer.

Test Procedure for Residential Water Heaters

Current Test Procedure

To determine compliance with DOE standards, manufacturers must follow the test procedures specified at 10 CFR 430.23(e) for residential water heaters as of June 10, 1998. The methods to conduct the test procedure are further specified in 10 CFR 430 Appendix E to Subpart B. These are also in the Electronic Code of Federal Regulations.

Final Rule: Test Procedures, Federal Register, 63 FR 25996 (May 11, 1998)

For further guidance or to submit questions related to the implementation of this test procedure, visit the Guidance and Frequently Asked Questions page.

Waivers, Exceptions, and Exemptions

Waivers

Test procedure waivers have not been issued for residential water heaters.

For information about obtaining test procedure waivers, see 10 CFR section 430.27.

Exceptions

DOE's Office of Hearings and Appeals has not authorized exception relief for residential water heaters.

For information about obtaining exception relief, see 10 CFR part 1003.

State Exemptions to Federal Preemption

DOE has not exempted any state from this energy conservation standard. States may petition DOE to exempt a state regulation from preemption by the federal energy conservation standard. States may also petition DOE to withdraw such exemptions. For details, see 10 CFR part 430, subpart D.

Small Business Exemptions

Any manufacturer of a covered product with annual gross revenues that do not exceed $8,000,000 from all its operations and meets certain other conditions may apply for an exemption to the energy conservation standard. For details, see 10 CFR part 430, subpart E.

Statutory Authority

The current energy conservation standards for residential water heaters are mandated by Part A, the "Energy Conservation Program for Consumer Products Other Than Automobiles" of Title III of the Energy Policy and Conservation Act (EPCA), as amended. (42 U.S.C. 6291–6309) These appliances are treated as covered products under Part A. (42 U.S.C. 6292(a)(4))

Historical Information

The National Appliance Energy Conservation Act of 1987 amended EPCA by establishing energy conservation standards for residential water heaters and requiring DOE to consider amending standards in two subsequent rulemakings.

On January 17, 2001, DOE issued a final rule to update the standards for residential water heaters to the current standards. On April 16, 2010, DOE issued another final rule, again updating the energy conservation standards. Compliance with these standards will be required on April 16, 2015.

In 1998, DOE published a final rule that amended the original test procedure for residential water heaters. The rule updated the first hour rating test for storage water heaters and revised the test procedure so that it could apply to electric and gas-fired instantaneous water heaters. There are currently ongoing test procedure rulemakings for standby and off mode and for active mode.

Helpful Links and Contact Information

Helpful Links

Find tips and guidance for making your home, workplace, or vehicle more energy efficient visit EnergySaver.gov.

DOE supports the testing and verification of ENERGY STAR^® products in close collaboration with the Environmental Protection Agency. ENERGY STAR qualified gas condensing water heaters can save over $100 a year in energy costs compared to the standard model. High efficiency gas storage water heaters can save about $30 a year compared to the standard model. Heat pump water heaters can save the average household almost $300 per year on its electric bills compared to a standard electric water heater. Solar water heaters can reduce annual hot water costs by 50%. Whole home gas tankless water heaters can save the typical family more than $100 per year on gas bills.

Contact information

For more information related to the regulation of this product, please email:

water_heaters@ee.doe.gov