Tricks of the trade

Water heater ENERGY STAR ratings explained

Heather Mahr, a Ferguson author

by Heather Mahr

 

Water heaters are one of the top energy-consuming appliances in residential applications, which makes it important for plumbing and contracting pros to help customers find a water heater that is energy efficient. 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. Knowing what qualifies a water heater to become ENERGY STAR certified will help you talk to your customers about water heater energy efficiency. Help your customers choose a water heater that will save them money over time by understanding how water heaters earn the ENERGY STAR Label.

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How does a water heater earn an ENERGY STAR Label?

ENERGY STAR Labeled-products of all kinds must provide measurable and significant energy savings without sacrificing performance. For water heaters, the standards for earning an ENERGY STAR Label are high but can be categorized in two primary steps. First, a water heater must meet certain requirements to make it eligible for the program. Then, If the requirements are met and the water heater is eligible, it must then meet the criteria set forth by the EPA. The criteria varies 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.

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Click the options below to find more information about ENERGY STAR terminology, requirements and eligibility:

Water heater efficiency and safety terminology

The language used to explain water heater efficiency can be highly technical for end consumers. While you might use these terms on a daily basis in your trade, they might be challenging for your customers to understand. 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 Underwriter’s Laboratories that has operated for over 100 years. 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 water heaters

The requirements that a water heater must meet in order to make it eligible for the ENERGY STAR program vary depending on the type of water heater. Discover the requirements for storage, or tank, and tankless water heaters to help you choose the right one for your customer’s needs.

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.
    • Must 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.
    • Store up to 120 gallons of water according to manufacturer specs if the tank is included.
Storage or tank water heaters
  • Heat production must be initiated by water flow activation.
  • 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.
  • The input must be between 50,000 - 200,000 Btu per hour.
If a water heater meets these requirements, then it is eligible to be included in the ENERGY STAR program.

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ENERGY STAR criteria for eligible 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 ENERGY STAR Label. Read 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 is your source for water heaters, repair parts and the plumbing supplies you need to help you save your customers’ utility costs. Shop our online offering of water heater parts and accessories, and contact your local Ferguson to get the water heater you need to get the job done.

Heather Mahr, a Ferguson author

Heather Mahr

As Ferguson’s in-house copywriter, Heather is dedicated to providing readers with valuable information. She is passionate about helping people find the answers they need to make their life easier with her words.