Brand and Model
This is how a particular water heater is identified. Manufacturers identify products they produce using the brand and model number. Some products may also be identified with a name or SKU, which is different from the brand or model number. You should always be able to find the brand and model number on a product.
Model numbers sometimes contain wildcard characters, such as *, #, and X, that are placeholders for non-energy attributes, such as color.
Fuel type refers the kind of fuel the water heater uses to heat the water, either natural gas or propane.
The type of vent used by the water heater: Atmospheric Vent, Direct Vent, or Power Vent.
Volume is the capacity of the tank, in gallons.
Tank Height (inches)
Tank height is the distance from the bottom of the water heater�s tank to the top of its tank.
Height to Vent (inches)
Height to vent is the distance from the bottom of the water heater�s tank to its vent.
Tank Diameter (inches)
Tank diameter is the width or diameter of the water heater�s tank.
Vent Size (inches)
Vent size is the width or diameter of the vent opening.
Input (Thousand BTU per hour)
Input refers to the burner size of the water heater, in thousand BTU per hour.
Energy Factor (EF)
Energy Factor is the ratio of useful energy output from the water heater to the total amount of energy delivered to the water heater. EF is a metric used to compare relative efficiencies of water heaters. The higher the EF is, the more efficient the water heater. EF is determined by the DOE test procedure, Code of Federal Regulations, Title 10, Section 430.
Therms/year refers to the amount of natural gas consumed by the water heater according to its Energy Factor determined by the DOE test procedure, Code of Federal Regulations, Title 10, Section 430.
Gallons/year refers to the amount of propane consumed by the water heater according to its Energy Factor determined by the DOE test procedure, Code of Federal Regulations, Title 10, Section 430.
First Hour Rating (gallons per hour)
First-Hour Rating is the amount of hot water (in gallons) a storage water heater can supply per hour (starting with a tank full of hot water).
Recovery efficiency refers to how efficiently the heat from the burner is transferred to the water in the tank.
Min Warranty - Tank (years) and Min Warranty - Parts (years)
Warranty is an assurance by the manufacturing partner that the purchased equipment (tank) and components (parts) are warranted for a certain required period-of-time, depending on the technology. Minimum warranty is the shortest warranty you can receive on the qualified water heater model.
Models that appear in parenthesis and in red are discontinued by manufacturers, but may still be available in stores. Discontinued models will appear on this list for a year after their last production date to allow retailers to clear inventory. These models are still ENERGY STAR qualified, but they are no longer manufactured. Sponsors, such as utilities, may honor incentives for discontinued models at their discretion.