The short answer
Rheem and A.O. Smith are both top-tier tank water heater brands, and either will serve an Atlanta home well. Head's installs more Rheem because we're a Rheem Pro contractor with factory warranty backing, but A.O. Smith is an excellent, widely-serviceable alternative — the right pick comes down to model tier, fuel type, and price.
How do they stack up overall?
These two brands sit at the top of the residential water heater market and are far more alike than different. Both build reliable gas, electric, tankless, and heat-pump models; both offer value-through-premium tiers; and both have excellent parts availability. You're choosing between two strong options, not avoiding a weak one.
Where does each brand pull ahead?
The practical edges:
- Rheem — our most-installed line; as a Rheem Pro contractor we get factory training and smoother warranty handling, plus standout ProTerra hybrid and feature-rich Prestige models
- A.O. Smith — deep commercial-grade engineering in its heavy-duty residential models, broad availability, and strong higher-efficiency options
- Warranty/longevity — comparable tier-for-tier; the longer-warranty model from either brand generally outlasts the entry model from both
- Parts/service — both excellent; Rheem is fastest for us specifically because we stock and install it most
What's the failure mode to avoid?
The mistake isn't picking the 'wrong' brand — it's buying on tank gallons or sticker price alone and ending up with an undersized or entry-tier unit that disappoints. Both brands' value tiers are fine for short-term holds but skimp on tank protection compared to their premium lines.
Sizing to your real first-hour demand and matching the tier to how long you'll own the home matters far more than the logo.
Don't shop on price alone
An entry Rheem and an entry A.O. Smith are closer to each other than either is to its own premium tier. Decide the tier first, then the brand.
Which should you choose?
If you want the line we know best and the smoothest warranty path, choose Rheem. If you want a heavy-duty A.O. Smith model or simply prefer it, that's a sound choice too — we'll install either correctly. For a typical metro-Atlanta home, we'll usually quote a mid-to-premium Rheem and a comparable A.O. Smith so you can decide with both numbers in front of you.
No. We install more Rheem because we're a Rheem Pro contractor, but we install and service A.O. Smith and other brands too. We'll quote both so you can compare honestly.
Tier-for-tier they're very comparable. Reliability and lifespan track more with the model tier (tank lining, anode, warranty) and with maintenance than with the brand name.
Terms in this guide
- Uniform Energy Factor (UEF)
- The federal efficiency rating for water heaters — the higher the UEF, the more hot water you get per dollar of energy. It is the apples-to-apples number to compare brands and models, because every manufacturer is tested the same way.
- First Hour Rating (FHR)
- For tank water heaters, how many gallons of hot water the unit can deliver in a busy first hour starting full. Sizing to your household's real peak demand (back-to-back showers, laundry, dishwasher) matters more than tank gallons alone.
- Anode rod
- A sacrificial metal rod inside a tank water heater that corrodes on purpose so the steel tank does not. Replacing a spent anode rod on schedule is one of the cheapest ways to extend a water heater's life.
- Heat pump water heater (HPWH)
- A highly efficient electric water heater that moves heat from the surrounding air into the water tank instead of generating heat directly. It can use roughly a third of the energy of a standard electric tank and may qualify for federal tax credits.