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State GCF-40 1**

State GCF-40 1** is in the DOE listing as of Oct 26, 2026.

  • Gas storage water heater
  • 2 listed models

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

Its figures are also listed under A. O. Smith GCF-40 1**.

Storage volume
38gallons
UEF
0.64Uniform energy factor
First-hour rating
70gallonsHot water in the first hour
See it among every gas storage model

Advertised and certified figures

State GCF-40 1**: advertised and certified
State GCF-40 1**: advertised and certified Size: advertised 40 gal, certified 38 gal (advertised nominal size, certified storage volume). Size: advertised 38 gal, certified 38 gal (certified storage volume). UEF: advertised 0.64, certified 0.64. UEF: advertised 0.64, certified 0.64 (advertised up to). Size · advertised nominal size, certified storage volume Advertised 40 gal Certified 38 gal Size · certified storage volume Advertised 38 gal Certified 38 gal UEF Advertised 0.64 Certified 0.64 UEF · advertised up to Advertised 0.64 Certified 0.64
FigureAdvertisedCertifiedAdvertiserRead
Size 40 gal, nominal size 38 gal storage volume State Read Oct 4, 2026
Size 38 gal 38 gal storage volume State Read Oct 4, 2026
UEF 0.64 0.64 State Read Oct 4, 2026
UEF up to 0.64 0.64 State Read Oct 4, 2026
First-hour rating 70 gal 70 gal State Read Oct 4, 2026

Certified figures by listed model

Model numberStorage volume (gal)UEFFirst-hour rating (gal)Recovery efficiencyDraw pattern
GS6-40-HBFT 1*1380.647073%Medium
GS6-40-YBFT 1**380.647073%Medium

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

It holds 38 gallons in the test, 2 gallons less than its 40-gallon sold size. It delivers 70 gallons of hot water in the test's first hour. Its tank holds 38 gallons, so reheating adds 32 gallons during the first hour. Of 763 gas storage models, 510 give more hot water in the first hour. The median gas storage model gives 78 gallons in its first hour.

As of Oct 26, 2026, it was not listed as ENERGY STAR certified. In tests, 64% of the energy it uses ends up as hot water (UEF 0.64). Its test simulated a day of medium hot water use (its draw pattern). Of 288 gas storage models with the same draw pattern, 43 have a higher UEF. A UEF of 0.60 is the median for its type and draw pattern. The water took in 73% of the energy used to reheat it (its recovery efficiency).

Its 2 model numbers are GS6-40-HBFT 1*1 and GS6-40-YBFT 1**. There are 5 more basic models with the same test figures. Each of them is listed under a different brand. For the full group, see the A. O. Smith GCF-40 1**.

In one state, one rebate program may accept it.

Also listed as

They carry every figure in the table above.

Rebates

ProgramStateStatusProgram page
Xcel Energy MINNESOTA RESIDENTIAL ENERGY EFFICIENCY PROGRAMS (gas storage, gas tankless) MN May qualify Its own page

Programs change their terms. Check the program's own page before you buy.

Updated Oct 26, 2026 · Methodology

Not covered

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