This is the big-tent comparison — the two dominant residential water heater manufacturers in North America. AO Smith (Reliance, State, Signature, Whirlpool) vs Rheem (Rheem, Ruud, Richmond, Marathon).
Side-by-side
| Reliance | Rheem | |
|---|---|---|
| Manufacturer family | AO Smith | Rheem |
| Channel | Ace, True Value, Do it Best, plumbing wholesale | Home Depot, plumbing wholesale |
| 6-yr tier | Standard 6-NORT | Performance |
| 9-yr tier | Extended 9-NORT | Performance Plus |
| 12-yr tier | Premium 12-50-NORT | Performance Platinum |
| Hybrid | HPHE | ProTerra (4.0+ UEF — best in class) |
| Customer service | 1-800-365-4054 | 1-800-621-5622 |
Where Rheem leads
- ProTerra Hybrid: 4.0+ UEF beats AO Smith Voltex 3.45 UEF significantly. The single biggest tech-lead difference between the families
- Tankless condensing: Rheem RTGH series outperforms AO Smith family tankless lineup (Reliance doesn\'t make a tankless)
- Home Depot install service: turnkey nationwide; wider availability than Reliance hardware-store channel
- EcoNet Wi-Fi integration: Rheem\'s smart app is more mature than AO Smith\'s connectivity
Where Reliance leads
- Hardware-store availability: Ace/True Value typically have a 50-gal 6-NORT in stock; Home Depot can be hit-or-miss on Performance same-day
- Pricing on standard atmospheric: Reliance 6-50-NORT typically $50-100 below Rheem Performance 50-gal at Home Depot
- Mini-Tank line: SOMS 6-gal and 10-gal have no Rheem residential equivalent (Rheem briefly had a similar line, discontinued)
- Power Vent pricing: Reliance 6-PVRT often beats Rheem Performance Power Vent on the equivalent capacity
Pricing comparison (volume 50-gal NG)
| Tier | Reliance | Rheem |
|---|---|---|
| 6-yr | 6-50-NORT: $749-949 | Performance: $799-999 |
| 9-yr | 9-50-NORT: $849-1,049 | Performance Plus: $899-1,099 |
| 12-yr | 12-50-NORT: $949-1,199 | Performance Platinum: $999-1,249 |
| 66-gal Hybrid | HPHE-66: $1,599-1,999 | ProTerra 65: $1,899-2,299 (higher UEF) |
Reliability
Both families are reliable when maintained. The dominant factor in lifespan is anode rod replacement at year 4-5, not which brand you bought. Field reliability is essentially indistinguishable across tiers between the two families.
Which to choose
- Hybrid Heat Pump: Rheem ProTerra wins on UEF (4.0+ vs 3.45). Worth the upcharge if heat pump is the choice
- Tankless: Rheem only (Reliance has no tankless line)
- Atmospheric gas / electric standard: functionally equivalent. Choose by retailer + price
- Point-of-use mini-tank: Reliance SOMS
- Power Vent: functionally equivalent; price + channel preference
Bottom line
Same tier of standard tank, either family is fine. Rheem leads on Hybrid Heat Pump UEF and condensing tankless. Reliance leads on hardware-store availability and point-of-use mini-tanks. For typical 50-gallon atmospheric gas replacement, choose by which retailer is closer and which has better same-day stock.