Rheem’s name shows up on more water heaters in North America than any other brand, which sounds like marketing copy until you actually check the numbers. The company has been building water heating equipment since 1925, exactly 101 years as of 2026, and it’s currently the largest manufacturer of water heating products in North America. That kind of longevity earns a closer look before you buy any single product they make.
Rheem produces both gas and electric tankless water heaters, with electric models like the RTEX-24 ($549, 24kW) built for whole-home use and gas models reaching up to 96% efficiency according to the company’s own published figures. Across its RTEX electric lineup and its tankless gas offerings, Rheem consistently ranks as a top-selling brand on Amazon and Home Depot, backed by real review volumes in the thousands per product.
Rheem’s Tankless Product Lines
Rheem splits its tankless lineup into two main categories: electric (the RTEX series) and gas (multiple lines including condensing and non-condensing options).
The RTEX electric series ranges from small point-of-use units (3.5kW, up to 0.9 GPM) to the whole-home RTEX-24 (24kW, up to 5.9 GPM), all sharing a common self-modulating design that only draws the power needed for current demand.
Rheem’s gas tankless lineup includes higher-capacity condensing units capable of up to 96% efficiency per the company’s published specifications, generally suited to larger households or those who already have gas line infrastructure and want to avoid the electrical demands of an electric system entirely.
What Sets Rheem Apart From Competitors
Scale is the most concrete differentiator. Being the largest water heater manufacturer in North America means Rheem’s replacement parts (heating elements, control boards, sensors) are widely stocked, and licensed plumbers and electricians are broadly familiar with installing and servicing Rheem units specifically. That familiarity translates into more predictable service costs and faster repairs compared to smaller or newer brands.
Rheem also maintains manufacturer warranty documentation and support resources directly accessible through retailers like Amazon, and its products carry the kind of large-scale review volume (over 4,000 verified reviews for the RTEX-24 alone) that gives buyers a genuinely useful data set to evaluate before purchasing, rather than relying on a handful of curated testimonials.
Where Rheem Falls Short
Being the market leader doesn’t mean Rheem is the top performer on every individual metric. On Home Depot’s platform specifically, the RTEX-24 holds a 3.9-star rating across 2,814 reviews, noticeably behind competitor EcoSmart’s ECO 27 at 4.2 stars, and well behind Stiebel Eltron’s Tempra 29 Plus at 4.6 stars. That gap reflects real, documented issues in a portion of Rheem’s electric tankless reviews, including heating element failures and inconsistent water temperature complaints that show up repeatedly in verified purchase reviews.
Rheem’s electric tankless units also don’t carry Energy Star certification, unlike some premium competitors. This doesn’t mean the units are inefficient, Rheem cites Department of Energy figures showing whole-home electric tankless models can save up to 34% on water heating costs compared to tank systems, but buyers specifically prioritizing third-party certified efficiency will find that badge on competitor products instead.
Is Rheem a Trustworthy Brand to Buy From?
Based on scale, longevity, and review volume, yes, Rheem is a reasonable brand to buy from for tankless water heating, particularly if you value parts availability and installer familiarity over squeezing out the last percentage point of flow rate or efficiency rating. The company’s century of operation and current market position aren’t accidents, they reflect a product line that performs reliably enough for millions of households, even accounting for the real complaints documented in individual reviews.
That said, “biggest brand” doesn’t automatically mean “best individual product” for your specific situation. If you’re deciding between a Rheem unit and a competitor, compare the specific models on flow rate, price, and review data rather than assuming brand name alone settles the question.
For a closer look at how Rheem’s flagship electric tankless model stacks up against its main competitor, see our Rheem RTEX-24 vs EcoSmart ECO 27 comparison.
Rheem RTEX-24 24kW 240V Electric Tankless Water Heater - Check Current Price on Amazon
The Bottom Line
Rheem earns its position as the largest water heater manufacturer in North America through genuine scale, parts availability, and a century of manufacturing experience. Its tankless products perform solidly but aren’t universally the top-reviewed option in every category, so compare specific models rather than buying on brand name alone.
Frequently Asked Questions
Is Rheem a good brand for tankless water heaters? Yes, Rheem is the largest water heater manufacturer in North America with over a century of manufacturing history, offering both electric and gas tankless options with wide parts availability and installer familiarity.
How long has Rheem been making water heaters? Rheem was founded in 1925 by brothers Richard and Donald Rheem, making it a 100+ year old company as of 2026.
Are Rheem tankless water heaters reliable? Generally yes, though review data shows some rate of component failure, particularly heating elements, in a portion of units. The RTEX-24 holds a 4.2-star Amazon rating across more than 4,000 reviews.
Does Rheem make gas or electric tankless water heaters? Both. Rheem’s RTEX series covers electric tankless models, while its other product lines include gas tankless water heaters reaching up to 96% efficiency according to company specifications.
Is Rheem better than EcoSmart or Stiebel Eltron? Not universally. Rheem offers better parts availability and brand longevity, but Home Depot review data shows both EcoSmart’s ECO 27 (4.2 stars) and Stiebel Eltron’s Tempra 29 Plus (4.6 stars) outscoring the Rheem RTEX-24 (3.9 stars) on that platform.
Are Rheem tankless water heaters Energy Star certified? Rheem’s electric tankless units, including the RTEX-24, are not Energy Star certified, though the company cites Department of Energy data showing meaningful energy savings compared to tank systems.
What is Rheem’s most popular tankless model? The RTEX-24 is one of Rheem’s best-selling electric tankless models, with over 4,000 reviews and 100+ units sold per month on Amazon as of 2026.
Does Rheem offer a warranty on tankless water heaters? Yes, Rheem provides manufacturer warranty documentation for its tankless products, though specific terms vary by model and should be confirmed directly before purchase.
Where are Rheem water heaters made? Rheem manufactures products across multiple facilities; specific sourcing can vary by product line and should be confirmed through official Rheem documentation for the exact model you’re considering.
Should I buy a Rheem tankless water heater or a competitor? Compare the specific models you’re considering on flow rate, price, and current review data rather than deciding on brand reputation alone, since competitors can outperform Rheem on individual metrics depending on the model.
References
- Rheem company history and product information, Amazon.com manufacturer content, accessed July 2026: https://www.amazon.com/dp/B01MS9DVEE
- Home Depot customer review data for Rheem RTEX-24, EcoSmart ECO 27, and Stiebel Eltron Tempra 29 Plus, accessed July 2026
- Rheem citation of U.S. Department of Energy water heating savings figures, via Amazon manufacturer content, accessed July 2026