A professional plumber measures the space two residential gas water heaters are using in a basement.
Trade Talk

What is an ENERGY STAR water heater?

Helping customers make smart choices for their homes can help you grow your business. Discover what makes an ENERGY STAR water heater so you can help your customers choose the option that will save them money in the long run.

How does an ENERGY STAR water heater earn the label?

The Environmental Protection Agency, or EPA, developed the ENERGY STAR program in order to make it simple for consumers to know which appliances are the most energy efficient. ENERGY STAR-labeled products of all kinds must provide measurable and significant energy savings without sacrificing performance. The ENERGY STAR water heater product criteria can be categorized in two primary steps.

First, a water heater must meet certain requirements to make it eligible for the program. Then it must also meet the criteria set forth by the EPA. The criteria vary depending on the type of water heater. Additionally, the standards for the ENERGY STAR program are subject to change based on technology advancements and updates to legislation.

The National Appliance Energy Conservation Act, or NAECA, raised water heater efficiency standards across the country, but an ENERGY STAR water heater goes even further.

Water heater efficiency and ENERGY STAR program requirements

Knowing what qualifies a water heater to earn the ENERGY STAR label will help you talk to your customers about water heater energy efficiency. Discover the technical terms as well as criteria for conventional and tankless water heaters for gas or electric.

Water heater efficiency and safety terminology

The language used to explain water heater efficiency can be highly technical for end consumers. Brush up on the definitions of technical water heater terms to help you educate your customers about water heater efficiency.

  • ANSI: The American National Standards Institute is a private, not-for-profit organization that develops and determines conformity standards and safety requirements for a variety of products. Manufacturers can comply with voluntary ANSI standards in order to obtain ANSI accreditation.

  • Energy factor rating: Also known as the EF rating, this measurement is expressed as a ratio that indicates the overall efficiency of a water heater. A water heater that generates more hot water while requiring less energy to power the unit will have a higher EF rating.

  • First-hour rating: This term is applicable to storage water heaters. The first-hour rating, or FHR, is an estimation of how much water a unit will heat within the first hour of the water heater reaching full temperature.

  • Gallons per minute: This term is applicable to tankless water heaters. Gallons per minute, or GPM, is the number of gallons of hot water that a tankless water heater can generate in a minute while maintaining a consistent water temperature increase of 77°F.

  • UL: A private organization known as Underwriters Laboratories that has operated for more than a century. They work with manufacturers of a variety of products to provide verifiable testing and help to create industry standards for safety and operational requirements.

ENERGY STAR program requirements for types of water heaters

Each type of water heater must meet different requirements to be eligible for the ENERGY STAR program. Discover the details to help you choose the right one for your customer.

Storage or tank water heaters: The unit must store and control the temperature of the water up to only 180°F, regardless of how it is powered.

  • Gas storage water heaters must have an input of 75,000 Btu per hour or less and store between 20-100 gallons of water according to manufacturer specs.

  • Electric heat pump storage water heaters must have a maximum current rating of 24 amperes with a minimal input under or equal to 250 volts and store up to 120 gallons of water according to manufacturer specs if the tank is included.

Tankless water heaters: Heat production must be initiated by water flow activation, and water temperature must be controlled up to 180°F. The tank must hold a maximum of 1 gallon of water per 4,000 Btu per hour of input, and the input must be between 50,000-200,000 Btu per hour.

Water heaters that meet the requirements above are eligible to be included in the ENERGY STAR program, but they also must meet EPA criteria to earn the label.

EPA criteria for eligible ENERGY STAR water heaters

Water heaters that are eligible for the ENERGY STAR program must meet the EPA criteria for efficiency and safety in order to earn the label. Discover the EPA’s criteria for gas and electric tank water heaters and tankless water heaters to explain to your customers why units with these specs will help them save on utility costs.

EPA criteria for electric tank water heaters

  • EF rating must be at least 2.0 for tanks up to 55 gallons and at least 2.2 for tanks larger than 55 gallons.

  • The FHR must be at least 50 gallons per hour or more.

  • The manufacturer’s warranty must cover the unit for at least 6 six years or more on sealed systems.

  • In order to ensure safety, the unit must meet UL 174 and UL 1995 requirements.

  • As a reporting requirement only, the unit must be able to report the ambient temperature at which it operates solely on electric resistance and the compressor cuts off.

EPA criteria for gas tank water heaters

  • EF rating must be at least .67 for units with a 55-gallon tank or less. Tanks with a storage capacity greater than 55 gallons must have a .77 EF rating or higher.

  • The unit must have a FHR of 67 gallons per hour or more.

  • The manufacturer’s warranty on the unit must cover it for at least 6 years or more, including parts.

  • To ensure safety, the unit must meet the requirements of ANSI Z21.10.1/CSA 4.1.

EPA criteria for tankless water heaters

  • The unit must have an EF rating of .90 or higher.

  • The unit must be able to supply 2.5 GPM of water over 77°F during steady operation.

  • The manufacturer’s warranty must cover the heat exchanger for at least 6 years and at least 5 years for parts.

  • The safety specs must meet the requirements of ANSI Z21.10.3/CSA 4.3.

Ferguson: your source for an ENERGY STAR water heater

Helping your customer choose the right ENERGY STAR water heater can save them money on water and power bills while helping you expand your business. Ferguson is your source for water heaters, repair parts and plumbing supplies. Shop online or contact your local Ferguson to get the water heater you need to get the job done.