Most tankless water heaters sold in the USA are made in Japan, Korea or Mexico. The one we could confirm is built here is a line of three-phase electric tankless heaters for factories, labs and businesses, machined, welded and assembled in Sarasota, Florida.
A tankless heater is mostly its heat exchanger and controls. Each listing names what is known to come from elsewhere.
Stiebel Eltron USA sells German-designed tankless, heat pump and solar water heaters, and builds its C Plus three-phase electric tankless water heaters for factories, labs and other commercial users at its own plant in Sarasota, Florida. The US arm of Germany's family-owned Stiebel Eltron Group is based in West Hatfield, Massachusetts.
Stiebel Eltron's C Plus page says: "All machining, welding, and assembly, of the C Plus series are made in our manufacturing plant in Sarasota, Fla." A 2019 report described its welders hand TIG-welding the heat exchangers there and testing every unit.
Where its elements, contactors and controls come from isn't stated, and its other tankless, heat pump and solar water heaters are designed by its German parent.
Production history: Stiebel Eltron bought Sarasota's Tankless Inc. in 2017 and has built the C Plus series there since; a February 2026 order form still lists the Sarasota plant.
Our rough estimate: parts of unknown origin (elements, contactors, controls) are about 15–35% of a heater's value.
Level 4 for its C Plus three-phase commercial tankless water heaters: Stiebel Eltron machines, welds and assembles its C Plus commercial tankless heaters in Sarasota, Florida; where its elements and controls come from isn't stated.
What "made in USA" means for tankless water heaters
Most are imported. A. O. Smith makes its tankless heaters in Mexico, and the big gas tankless brands are Japanese and Korean.
Some small US makers are hard to confirm. We're checking a Miami maker whose website no longer loads, and other makers that no longer say where their heaters are made.
Each listing's research notes show what was checked and when, including our rough estimate of how much of the value is imported. Ratings are rechecked as companies answer.
Tankless water heater makers by state
Florida: Stiebel Eltron (Sarasota plant)
Change log
What's changed since our last review on July 12, 2017?
1 listing is paused: Niagara Industries' website doesn't load, so we can't confirm it still makes tankless heaters in Miami.
Stiebel Eltron was re-checked and still builds its C Plus series in Sarasota, Florida.
Every maker now has a Made in USA level from 0 to 5, with the sources and research notes behind it. See how the levels work.
Listings checked by Dave Hurley.
Know a USA-made company we missed?
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A company may be based in the USA while making some products elsewhere. Check the manufacturer's own site for where a specific product is made.
