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Heat & Tap
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Water Heater Brands

Three companies make most of what is on the shelf. Knowing which is which changes how you shop.

By Brijon M., Owner and writer, MadGrey LLC·Last updated October 6, 2026·How we pick →

A. O. Smith makes A. O. Smith and State, markets American Water Heaters, Reliance and Takagi, and owns Lochinvar. Rheem manufactures under Rheem, Ruud and Richmond. Bradford White sells only through plumbing wholesalers to licensed trade. So several "different" brands on a shelf are the same factory.

The water heater aisle looks like a competitive market and largely is not. A handful of manufacturers produce under a dozen badges, which is why two tanks with different names can share dimensions, fittings and failure modes. That is useful to know in two situations: when you are comparing brands that are actually siblings, and when you are sourcing a replacement part.

The ownership map

Who makes and markets what, from company filings and brand statements
ManufacturerBrandsNotes
A. O. Smith CorporationA. O. Smith, State, American Water Heaters, Reliance, Takagi, LochinvarState and A. O. Smith are its own brands; it also markets American, Reliance and Takagi in North America, and acquired Lochinvar in 2011
Rheem ManufacturingRheem, Ruud, RichmondRheem states it manufactures water heaters under all three names
Bradford WhiteBradford WhiteWholesale only, to licensed trade. Not sold at big-box retail
RinnaiRinnaiTankless specialist, Japanese parent
NavienNavienTankless and combi specialist, Korean parent (KD Navien)
Stiebel EltronStiebel EltronGerman manufacturer, electric specialist
EcoSmartEcoSmartElectric tankless, retail-focused

The big three

Tankless specialists

Siblings and specifics

How much does the brand actually matter?

Less than people think, and in a specific way. Across these manufacturers the tanks are glass-lined steel with a sacrificial anode, the burners are conventional, and the failure mode is the same: the tank rusts through from the inside. What actually decides how long yours lasts is the anode rod and your water chemistry. How long water heaters last.

Where brand does matter:

  • Warranty terms and the conditions attached. Rheem requires online registration within 90 days of installation for the residential warranty, and its tankless gas warranty is not transferable to a new owner.
  • Feature availability. Integrated leak detection with an automatic shutoff is a Rheem feature on the Gladiator and ProTerra lines; direct-vent gas tanks with high first-hour ratings are a Bradford White strength.
  • Published data quality. Stiebel Eltron publishes a full rise-versus-flow table at two voltages. Most electric tankless brands publish a maximum GPM. That difference is the whole reason we rank Stiebel Eltron first on electric tankless.
  • Distribution. Bradford White is wholesale only, which rules it out as a same-day DIY purchase and makes it a specify-in-advance brand.
  • Parts availability in five years. A brand with national distribution is a better bet for a control board in 2031 than a thin-distribution import.

What goes in with it

A water heater is a system, not a box. These are the parts that go in with it, and the ones people discover they need halfway through the job.

  • Expansion tank

    Required by code on a closed system, which is most homes with a pressure-reducing valve.

  • Drain pan

    Cheap insurance anywhere the tank sits above something you care about.

  • Anode rod

    The part that decides when the tank leaks. Replacing it is the highest-value hour of maintenance there is.

Questions people actually ask

›Who makes the best water heaters?
No single manufacturer is best across the board. A. O. Smith has the widest retail gas range with the clearest first-hour ratings, Rheem has the best leak protection features, Bradford White makes the best direct-vent gas tanks, and Rinnai and Navien lead on tankless. Choose for the specific job.
›Are A. O. Smith and State water heaters the same?
Same company. A. O. Smith Corporation makes both the A. O. Smith and State brands, and also markets American Water Heaters, Reliance and Takagi in North America. Comparing A. O. Smith with State is comparing two badges from one manufacturer.
›Who makes Rheem water heaters?
Rheem Manufacturing, which produces water heaters under the Rheem, Ruud and Richmond brand names. If you need a part for a Ruud or Richmond unit, a Rheem parts counter is the place to start.
›Why can I not buy Bradford White at Home Depot?
Bradford White operates a professional-only sales policy, distributing strictly through wholesale channels to licensed trade professionals. The company says this ensures proper, safe, code-compliant installation. You will not find a new unit at a big-box retailer.
›Does the brand of water heater matter?
Less than warranty terms, feature set and sizing. Across these manufacturers the tank construction and the failure mode are broadly similar, and what decides service life is the anode rod and your water chemistry rather than the badge.
›Which water heater brand has the best warranty?
Of the units in our registry, the Rheem Gladiator at 12 years tank and parts with 3 years labor, and Rinnai at 15 years on the tankless heat exchanger. Read the conditions: Rheem requires registration within 90 days and the tankless warranty is not transferable.

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