AO Smith vs APEC Water Water Treatment
Updated February 23, 2026
Comparing AO Smith and APEC Water for Water Treatment — see how they stack up on price, warranty, certifications, and product range.
Side-by-Side Comparison
| Feature | AO Smith | APEC Water |
|---|---|---|
| Founded | Founded 1874 | Founded 1997 |
| 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 | 2-year manufacturer warranty; 1-year money-back guarantee on select systems |
| 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 APEC Water
APEC Water Systems is the leading US manufacturer of residential reverse osmosis drinking water filtration systems. Based in City of Industry, California, APEC designs and assembles all of their systems domestically. With over 25 years of industry experience, they have earned a reputation for high-quality components, long filter life, and responsive customer support. Their systems consistently rank among the top-rated on Amazon and independent review sites.
Known for: Top-rated reverse osmosis drinking water systems manufactured and assembled in the USA
Frequently Asked Questions
Is AO Smith or APEC Water better for water treatment?
Both are reputable brands. AO Smith is positioned in the mid-range price tier, while APEC Water 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. APEC Water offers 2-year manufacturer warranty; 1-year money-back guarantee on select systems.