AO Smith vs Aqua-Star Water Treatment
Updated February 23, 2026
Comparing AO Smith and Aqua-Star for Water Treatment — see how they stack up on price, warranty, certifications, and product range.
Side-by-Side Comparison
| Feature | AO Smith | Aqua-Star |
|---|---|---|
| Founded | Founded 1874 | |
| Country | United States | United States |
| Price Tier | mid-range | budget |
| Warranty | 6-year standard warranty on residential models; 10-year on select ProLine series; commercial warranties vary by model | |
| Certifications | 4 certifications | 0 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 Aqua-Star
Aqua-Star is a niche brand offering residential water treatment and purification systems. They focus on providing affordable point-of-use filtration solutions for homeowners seeking cleaner drinking water.
Known for: Affordable residential water purification and filtration systems
Frequently Asked Questions
Is AO Smith or Aqua-Star better for water treatment?
Both are reputable brands. AO Smith is positioned in the mid-range price tier, while Aqua-Star is in the budget 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. Aqua-Star offers standard warranty coverage.