Five US water heater brands matter for most residential decisions: Rheem, AO Smith, Bradford White, Rinnai, and Navien. Three are American (Rheem, AO Smith, Bradford White) and dominate the tank market. Two are Asian (Rinnai Japanese, Navien Korean) and dominate the tankless and combi-boiler markets. This page is the honest cross-brand comparison.
Quick verdict
| If you want… | Best brand |
|---|---|
| Tank water heater, mainstream availability | Rheem or AO Smith |
| Tank water heater, plumber-recommended, long lifespan | Bradford White |
| Heat pump / hybrid | AO Smith Voltex or Rheem ProTerra |
| Gas tankless, single best brand | Rinnai Sensei or Sensei RX |
| Gas tankless with buffer tank (no cold sandwich) | Navien NPE-A2 |
| Combi boiler (heat + DHW from one unit) | Navien NCB or NFC |
| Best app/Wi-Fi experience | Rinnai ControlR |
| Best customer service | Rinnai (5-min holds) or AO Smith |
Rheem — broad-line US specialist
The largest US residential water heater manufacturer by volume. Three-tier lineup (Performance / Performance Plus / Performance Platinum) covers gas, electric, hybrid (ProTerra), and tankless (RTGH). Sold at Home Depot, plumbing wholesalers, and Amazon. Strong nationwide dealer network. EcoNet smart-home app integrates with their broader HVAC product line.
Strengths: wide availability, competitive pricing, strong heat pump line, good warranty options at the Platinum tier (12-year)
Weaknesses: tankless is competent but not exceptional (vs Rinnai/Navien); some Performance-tier units feel built to price
See Rheem lineup.
AO Smith — heat pump leader
Second-largest US manufacturer. Strong tank and hybrid presence; tankless through their Takagi subsidiary. Voltex hybrid is arguably the category-leading heat pump. Signature / Signature Select / Signature Premier tier structure. Lowe's is the headline retailer; AO Smith branded products through plumbing wholesalers.
Strengths: best-in-class heat pump (Voltex), 12-year Signature Premier warranty matches Rheem Platinum, deep distributor network for parts
Weaknesses: tankless is via Takagi (separate brand, different installer network), confusing tier nomenclature
See AO Smith lineup.
Bradford White — plumber-channel premium
Unique among the major brands: not sold at retail. Bradford White ships exclusively through plumber/contractor wholesale distributors — no Home Depot, no Lowe's, no Amazon. The result: plumber community loyalty (BW has a reputation for build quality among professionals) and longer-than-rated tank lifespans (often 15-18 years vs 10-12 typical). Lineup centers on Defender atmospheric gas, ICON System (electronic ignition), Eco-Defender (low-NOx), AeroTherm heat pump, and Infiniti GR tankless.
Strengths: tank build quality (real reputational advantage), 15-year heat exchanger warranty on Infiniti GR tankless
Weaknesses: 6-year standard warranty (with 10-year upgrade kit) is shorter on paper than Rheem Platinum; no retail availability means homeowners can't compare in person
Rinnai — tankless specialist
The largest tankless brand in the US. Japanese, founded 1920. Tankless-only product family — no tanks. Five product lines: Sensei (RU), Sensei RX (RX), Sensei+ (RUR), Luxury Series (RL), Value Series (V). Sensei RX with built-in recirculation pump and Circ-Logic learning firmware is the category-defining premium tankless. 15-year heat exchanger warranty on Sensei matches the longest in the market.
Strengths: best app (ControlR), best customer service (5-min phone holds), deepest tankless dealer network, mature recirculation feature set, J.D. Power #1 in tankless satisfaction
Weaknesses: no tank options (forces tankless decision), Value Series gets mixed reviews mostly due to install mistakes
See Rinnai lineup.
Navien — combi boiler + buffer-tank tankless
Korean. Two distinctive product strengths: (1) the NPE-A2 tankless with built-in 0.5-gallon buffer tank — the only mainstream tankless that eliminates cold-sandwich out of the box; (2) the NCB / NFC combi boiler line — single unit provides space heat + DHW for hydronic-heated homes.
Strengths: buffer tank solves real cold-sandwich complaints, combi boiler line is the segment leader for hydronic-heat homes, 15-year heat exchanger warranty matches Rinnai
Weaknesses: NaviLink app is functional but less polished than Rinnai ControlR, customer service holds are longer (15-30 min vs Rinnai 5 min), first-gen NPE-A had reliability issues (fixed in current NPE-A2)
See Navien lineup.
By use case — which brand
"I need to replace a tank, same fuel, basic install"
Rheem Performance Plus or AO Smith Signature Select. Mid-tier, 9-year warranty, available at HD/Lowe's with same-day install. Bradford White if your plumber recommends and you're willing to go through the wholesale channel.
"I want maximum lifespan for the money"
Rheem Performance Platinum or AO Smith Signature Premier (12-yr warranty). Premium tier from either brand. Bradford White is the dark horse if your plumber will source it.
"I want to switch to heat pump and maximize rebates"
AO Smith Voltex. Category leader. Voltex 5 is cold-climate optimized. Rheem ProTerra is a competent alternative.
"I'm going tankless"
Rinnai Sensei RX if you want recirculation or have a return line. Navien NPE-A2 if cold-sandwich is your specific complaint or you don't have a return line. Rheem RTGH-95 if budget-sensitive on a standard tankless.
"I have hydronic heating and need both heat and DHW"
Navien NCB or NFC combi boiler. The clear segment leader. NCB-240 is the volume pick.
Warranty comparison
| Brand / Tier | Tank / Heat Exchanger | Parts |
|---|---|---|
| Rheem Performance Platinum | 12 years | 12 years |
| AO Smith Signature Premier | 12 years | 12 years |
| Bradford White (with upgrade kit) | 10 years | 10 years |
| Bradford White Infiniti GR tankless | 15 years | 5 years |
| Rinnai Sensei tankless | 15 years | 5 years |
| Navien NPE-A2 tankless | 15 years | 5 years |
| Navien NCB combi | 10 years | 5 years |
| Navien NFC fire-tube combi | 15 years | 5 years |
Head-to-head brand comparisons
- Rheem vs AO Smith
- Bradford White vs Rheem
- Bradford White vs AO Smith
- Rinnai vs Navien
- Rinnai vs Rheem
- Navien vs Rinnai
Brands worth skipping (or being cautious about)
- Whirlpool, GE, Kenmore — most are rebadged units from AO Smith or Rheem with worse warranty terms. Buy the underlying brand instead
- Bosch tankless — competent product but limited US dealer network. Long-term service availability uncertain
- Stiebel Eltron, Eemax electric tankless — fine for point-of-use; not adequate for whole-house unless you have very specific use cases
- House-brand units at hardware stores (not from major brands) — typically have shorter warranties and limited parts availability
Related guides
Bottom line
For most US homeowners, the choice is between Rheem and AO Smith for tank, Rinnai and Navien for tankless. Bradford White is the plumber-recommended dark horse on tank if your installer carries it. Heat pump: AO Smith Voltex is the category leader. Combi boiler: Navien. Get three quotes regardless of brand; install quality matters more than brand choice.