Electric water heaters (storage tank)
Resistance-element tanks — cheapest to install, dearest to run.
Data current as of July 18, 2026 · 856 certified units · source AHRI + ENERGY STAR + DOE CCMS
Highest UEF in this group
RELIANCE WATER HEATERS 6-40-SHMSE 1**
UEF 0.95 · 40 gal · $762 a year to run.
See installed costs →UEF (Uniform Energy Factor) is the DOE test rating — hot water delivered per unit of fuel or electricity, measured the same way across every fuel, so it is the one number that compares a gas tank to a heat pump.
The 20 highest-UEF of 856 certified units · 2 with a verified place to buy
| Brand & model | UEF | Capacity | Fuel | Annual cost | Buy |
|---|---|---|---|---|---|
| RELIANCE WATER HEATERS 6-40-SHMSE 1** | 0.95 | 40 gal | Electric resistance | $762 | Get quotes |
| STATE EN6-40-DMHS 1** | 0.95 | 40 gal | Electric resistance | $762 | Get quotes |
| STATE SHN-40-DHMS 1** | 0.95 | 40 gal | Electric resistance | $762 | Get quotes |
| STATE SHN-40-SHMS 1** | 0.95 | 40 gal | Electric resistance | $762 | Get quotes |
| RELIANCE WATER HEATERS 6-40-EMHSDH 1** | 0.95 | 40 gal | Electric resistance | $762 | Get quotes |
| AMERICAN MHNE3F40RS 1** | 0.95 | 40 gal | Electric resistance | $762 | Get quotes |
| AMERICAN MHNE3F40RD 1** | 0.95 | 40 gal | Electric resistance | $762 | Get quotes |
| A. O. SMITH E6-40M6-45SV 1** | 0.95 | 40 gal | Electric resistance | $762 | Get quotes |
| A. O. SMITH MHE6-40R-045D 1** | 0.95 | 40 gal | Electric resistance | $762 | Get quotes |
| AMERICAN STANDARD WATER HEATERS ESSS40T-***-*** | 0.94 | 40 gal | Electric resistance | $770 | Get quotes |
| AMERICAN STANDARD WATER HEATERS ESSS55T-055-*** | 0.94 | 55 gal | Electric resistance | $770 | Get quotes |
| RELIANCE WATER HEATERS 12-55-DXRT 1** | 0.94 | 55 gal | Electric resistance | $770 | Get quotes |
| AMERICAN EE10X-55H 1** | 0.94 | 55 gal | Electric resistance | $770 | Get quotes |
| STATE EEX-55-DXRT 1** | 0.94 | 55 gal | Electric resistance | $770 | Get quotes |
| A. O. SMITH EEP12-55H55DVF 1** | 0.94 | 55 gal | Electric resistance | $770 | Get quotes |
| A. O. SMITH PETX-55 1** | 0.94 | 55 gal | Electric resistance | $770 | Get quotes |
| BRADFORD WHITE ERE250L*-****** | 0.94 | 47 gal | Electric resistance | $770 | Get quotes |
| BRADFORD WHITE RE250L*-****** | 0.94 | 47 gal | Electric resistance | $770 | Get quotes |
| RHEEM XE38S06SB60U1 | 0.94 | 38 gal | Electric resistance | $770 | Buy |
| RHEEM XE38S06SB55U1 | 0.94 | 38 gal | Electric resistance | $770 | Buy |
Showing the top 20 by UEF. All 856 certified units in this group are filterable in the full database — we rank here rather than dump, because a table nobody can read is not a resource.
UEF and capacity are certified values from AHRI / ENERGY STAR / DOE CCMS; annual running cost is computed by us from national energy prices — see methodology. A tankless unit is rated on flow (GPM) rather than gallons, because it stores nothing.