The US residential water heater market is more concentrated than buyers usually realize — most of the brands on big-box shelves are produced by three corporate parents. This list maps the brand landscape, who owns what, and what the differences actually are between sibling brands sold side-by-side.
Brand ownership map
Rheem family (parent: Paloma Industries)
- Rheem — flagship residential brand, sold at Home Depot
- Ruud — Rheem's commercial-leaning brand, plumbing supply channel
- Richmond — Home Depot value brand
- Marathon — premium polybuthylene-tank electric line
- Takagi — Japanese tankless brand acquired in 2009, sold under both Takagi and Rheem badges
A.O. Smith family
- A.O. Smith — flagship brand, sold at Lowe's and through plumbing channels
- State — mid-tier plumbing-supply brand
- American — value brand through hardware stores
- Whirlpool — licensed brand at Lowe's (A.O. Smith manufactures, Whirlpool licenses the brand)
- U.S. Craftmaster — Lowe's-exclusive value brand
- Reliance — budget brand for rental property and value-conscious replacement
- GE-branded water heaters — also A.O. Smith-built under license
Independent: Bradford White
Privately held, family-owned since 1881. Wholesale-only distribution. Not at Home Depot, Lowe's, or online retail. The only major US residential brand outside the Rheem/A.O. Smith duopoly with meaningful market share.
Independent specialty: Rinnai, Navien, Bosch, Stiebel Eltron, Noritz
Tankless and heat-pump specialists. Each focuses on a narrower product range than the big two, with deeper engineering in their specific category. Rinnai dominates US gas tankless. Navien is the close second. Bosch and Stiebel Eltron are German-engineered alternatives. Noritz is the Japanese tankless specialist with strong commercial presence and growing residential share.
What sibling-brand differences actually are
When you see Rheem Performance Platinum at Home Depot and Richmond Essential at the same store, these are not the same unit with different paint. The actual engineering differences:
- Anode rod material and count. Premium brands ship 2 anodes; value brands ship 1.
- Tank lining quality. Same lining process but slightly different specification — the premium tank lining produces fewer rejects, contributing to the longer warranty.
- Burner output (gas units). Premium often 50K BTU; budget often 40K BTU. Faster recovery on premium.
- Insulation thickness. Premium often 2" foam; budget often 1.5". Modestly better standby loss.
- Dip tube type. Premium has self-cleaning curve; budget has straight tube.
- Warranty length. The single biggest practical difference — premium 12 years vs budget 6 years.
The hardware differences add up to a modestly more durable unit; the warranty difference is the cleanest signal of how confident the manufacturer is in the long-term outcome.
Brand selection by buying channel
Home Depot: Rheem (volume leader), Richmond (value), some A.O. Smith. The Rheem Performance Platinum is the default mid-market pick here.
Lowe's: A.O. Smith (volume leader), Whirlpool (A.O. Smith-built), U.S. Craftmaster (value). The A.O. Smith Signature Premier is the default mid-market pick here.
Plumbing supply houses (Ferguson, Hajoca, MORSCO): Bradford White (premium), State (mid), Ruud (Rheem's commercial), Rinnai/Navien tankless. The trade buys here.
Hardware stores (Ace, True Value): Reliance, American, some State. Value-tier for landlords and budget-constrained replacements.
Direct online (manufacturer / Amazon): EcoSmart, Stiebel Eltron, Bosch, Marey, Eccotemp — the specialty brands. Big-name brands generally do not sell direct online for installed units.
Brand selection by buyer type
DIY homeowner replacing failed tank: Rheem Performance Platinum or A.O. Smith Signature Premier. Both DIY-installable, both 12-year warranty, both at big-box.
Plumber-installed primary residence: Bradford White or Rheem Performance Platinum. Bradford White if the plumber prefers it; Rheem if they do not specifically push BW.
Rental property / vacation home / value: Rheem Performance, AO Smith ProMax, Reliance, or Richmond Essential. 6-year warranty matches the typical replacement cycle.
Tankless gas: Rinnai (largest service network) or Navien (best built-in recirculation).
Tankless electric: EcoSmart (lifetime warranty) or Rheem RTEX (Rheem service network).
Heat-pump: Rheem ProTerra or A.O. Smith Voltex.