AO Smith vs Bosch Water Heaters
Updated February 23, 2026
Comparing AO Smith and Bosch for Water Heaters — see how they stack up on price, warranty, certifications, and product range.
Side-by-Side Comparison
| Feature | AO Smith | Bosch |
|---|---|---|
| Founded | Founded 1874 | Founded 1886 |
| Country | United States | Germany |
| Price Tier | mid-range | premium |
| Warranty | 6-year standard warranty on residential models; 10-year on select ProLine series; commercial warranties vary by model | 5-year limited warranty on tankless water heaters; 6-year on electric models; varies by product |
| Certifications | 4 certifications | 3 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 Bosch
Robert Bosch GmbH is a global engineering and technology leader founded in Stuttgart, Germany in 1886. Their Home Comfort division (US operations in Londonderry, New Hampshire) manufactures high-efficiency tankless water heaters, heat pump water heaters, electric point-of-use units, boilers, and geothermal heat pump systems. Bosch is known for German engineering precision, energy efficiency, and compact designs that save space while delivering powerful performance.
Known for: German-engineered tankless and point-of-use water heaters with compact designs and high energy efficiency
Frequently Asked Questions
Is AO Smith or Bosch better for water heaters?
Both are reputable brands. AO Smith is positioned in the mid-range price tier, while Bosch is in the premium 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. Bosch offers 5-year limited warranty on tankless water heaters; 6-year on electric models; varies by product.