About WaterHeaterSpecs

WaterHeaterSpecs is an independent reference site run by Isabella Reed. It turns the U.S. EPA list of ENERGY STAR certified water heaters into pages you can read and a finder you can filter: by type, by size, by first-hour rating or flow, and side by side.

Why rating sets

Most heaters on the list are sold under more than one brand name with identical ratings. Grouping them into rating sets turns 1,138 listings into 187 distinct heaters, which is the number that matters when you compare.

Independence

The site is not affiliated with EPA, DOE, ENERGY STAR or any manufacturer, and it accepts no payment for placement. It shows no prices and gives no buying or sizing advice.

Sources

• U.S. EPA, ENERGY STAR Certified Water Heaters (data.energystar.gov, dataset pbpq-swnu), certified models as of October 27, 2026.
• Code of Federal Regulations, 10 CFR Part 430, Subpart B, Appendix E (DOE uniform test method for water heaters), via govinfo.gov.

How the data is prepared is described on Test and data. Corrections are welcome at support@waterheaterspecs.online.