AO Smith vs Ecosmart Water Heaters
Updated February 23, 2026
Comparing AO Smith and Ecosmart for Water Heaters — see how they stack up on price, warranty, certifications, and product range.
Side-by-Side Comparison
| Feature | AO Smith | Ecosmart |
|---|---|---|
| Founded | Founded 1874 | Founded 2007 |
| Country | United States | United States |
| Price Tier | mid-range | mid-range |
| Warranty | 6-year standard warranty on residential models; 10-year on select ProLine series; commercial warranties vary by model | Limited lifetime warranty on heat exchanger; 5-year on electronics; 1-year on parts |
| Certifications | 4 certifications | 2 certifications |
About AO Smith
A. O. Smith Corporation is one of the world's leading manufacturers of residential and commercial water heating equipment, headquartered in Milwaukee, Wisconsin since its founding in 1874. The publicly traded company (NYSE: AOS) has grown through strategic acquisitions to own major brands including State Water Heaters, Lochinvar, Takagi, Reliance, and Aquasana. A. O. Smith also operates one of the largest water treatment businesses globally, with significant market presence in North America, China, and India.
Known for: Industry-leading water heaters including the Vertex high-efficiency line, Cyclone commercial series, and pioneering heat pump water heaters
About Ecosmart
EcoSmart is a leading manufacturer of electric tankless water heaters based in Johnson City, Tennessee. Founded with a focus on energy efficiency and sustainability, EcoSmart's self-modulating technology adjusts energy output based on incoming water temperature and flow demand, ensuring you only heat water you need. Their compact, wall-mounted units have become some of the best-selling electric tankless water heaters on Amazon and at major retailers.
Known for: Best-selling electric tankless water heaters with patented self-modulating technology for maximum energy savings
Frequently Asked Questions
Is AO Smith or Ecosmart better for water heaters?
Both are reputable brands. AO Smith is positioned in the mid-range price tier, while Ecosmart is in the mid-range tier. Your choice depends on budget and specific feature needs.
Which brand has a better warranty?
AO Smith offers 6-year standard warranty on residential models; 10-year on select ProLine series; commercial warranties vary by model. Ecosmart offers Limited lifetime warranty on heat exchanger; 5-year on electronics; 1-year on parts.