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State GUC-50 4**

State GUC-50 4** is in the DOE listing as of Oct 26, 2026.

  • Gas storage water heater
  • 3 listed models

Not listed as ENERGY STAR certified on Oct 26, 2026.

Its figures are also listed under A. O. Smith GUC-50 4**.

Storage volume
48gallons
UEF
0.61Uniform energy factor
First-hour rating
84gallonsHot water in the first hour
See it among every gas storage model

Advertised and certified figures

State GUC-50 4**: advertised and certified
State GUC-50 4**: advertised and certified Size: advertised 50 gal, certified 48 gal (advertised nominal size, certified storage volume). Size: advertised 48 gal, certified 48 gal (certified storage volume). UEF: advertised 0.61, certified 0.61. UEF: advertised 0.61, certified 0.61 (advertised up to). Size · advertised nominal size, certified storage volume Advertised 50 gal Certified 48 gal Size · certified storage volume Advertised 48 gal Certified 48 gal UEF Advertised 0.61 Certified 0.61 UEF · advertised up to Advertised 0.61 Certified 0.61
FigureAdvertisedCertifiedAdvertiserRead
Size 50 gal, nominal size 48 gal storage volume State Read Oct 5, 2026
Size 48 gal 48 gal storage volume State Read Oct 5, 2026
UEF 0.61 0.61 State Read Oct 5, 2026
UEF up to 0.61 0.61 State Read Oct 5, 2026
First-hour rating 84 gal 84 gal State Read Oct 5, 2026

Certified figures by listed model

Model numberStorage volume (gal)UEFFirst-hour rating (gal)Recovery efficiencyDraw pattern
GS6-50-BRUT 4**480.618477%High
GSX-50-BRUT 4**480.618477%High
GW8-50-BRUT 4**480.618477%High

UEF is the uniform energy factor. A dash means the model has no such figure.

It holds 48 gallons in the test, 2 gallons less than its 50-gallon sold size. Over one hour from a full tank, it gave 84 gallons in the test (its first-hour rating). Reheating lets it give 36 gallons beyond the 48 gallons in its tank. In the first hour, 209 of the 763 gas storage models give more hot water. Among gas storage models, the median first-hour rating is 78 gallons.

On Oct 26, 2026, this heater was not listed as ENERGY STAR certified. In the test, 39% of its energy does not reach the hot water (UEF 0.61). In the test, daily hot water use was set to high (its draw pattern). Its UEF is lower than that of 419 of the 434 gas storage models with its draw pattern. For its type and draw pattern, the UEF runs from 0.61 to 0.90. When it reheats water in the test, 77% of the energy it uses ends up in the water.

It is sold as GS6-50-BRUT 4**, GSX-50-BRUT 4**, and GW8-50-BRUT 4**. There are 3 more basic models with the same test figures. The A. O. Smith, American, and RELIANCE WATER HEATERS brands list one or more of them. For the full group, see the A. O. Smith GUC-50 4**.

Also listed as

They carry every figure in the table above.

Updated Oct 26, 2026 · Methodology

Not covered

  • Changes to an advertised figure after the date beside it.