Hot Water List
Menu

Rheem PROG48-48U RH EC1

Rheem PROG48-48U RH EC1 is in the DOE listing as of Oct 26, 2026.

It has a labeled size of 48 gallons, a certified storage volume of 46 gallons, a certified UEF of 0.64, and a certified first-hour rating of 88 gallons of hot water.

Its advertised UEF of 0.63 from Rheem differs from the certified 0.64 (Read Oct 5, 2026).

  • Gas storage water heater
  • 2 listed models

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

Storage volume
46gallons
UEF
0.64Uniform energy factor
First-hour rating
88gallonsHot water in the first hour
See it among every gas storage model

Advertised and certified figures

Rheem PROG48-48U RH EC1: advertised and certified
Rheem PROG48-48U RH EC1: advertised and certified Size: advertised 48 gal, certified 46 gal (advertised nominal size, certified storage volume). Size: advertised 50 gal, certified 46 gal (advertised nominal size, certified storage volume). UEF: advertised 0.63, certified 0.64. Size · advertised nominal size, certified storage volume Advertised 48 gal Certified 46 gal Size · advertised nominal size, certified storage volume Advertised 50 gal Certified 46 gal UEF Advertised 0.63 Certified 0.64
FigureAdvertisedCertifiedAdvertiserRead
Size 48 gal, nominal size 46 gal storage volume Rheem Read Oct 5, 2026
Size 50 gal, nominal size 46 gal storage volume The Home Depot Archived copy, Sep 30, 2025
UEF 0.63 0.64 Rheem Read Oct 5, 2026

Certified figures by listed model

Model numberStorage volume (gal)UEFFirst-hour rating (gal)Recovery efficiencyDraw pattern
PROG48-48U RH EC1460.648877%High
XG50T06EN48U0460.648877%High

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

It holds 46 gallons in the test, 2 gallons less than its 48-gallon sold size. Starting full, it gives 88 gallons of hot water in its first hour of use. That is 42 gallons more than its tank holds, since it reheats during the hour. Among 763 gas storage models, 135 have a higher first-hour rating. Among gas storage models, the median first-hour rating is 78 gallons.

It was not listed as ENERGY STAR certified on Oct 26, 2026. In tests, 64% of the energy it uses ends up as hot water (UEF 0.64). The daily hot water use in the test, called its draw pattern, was high. Of 434 gas storage models with the same draw pattern, 255 have a higher UEF and 95 a lower one. For its type and draw pattern, the median UEF is 0.66. When it reheats water in the test, 77% of the energy it uses ends up in the water.

It is sold as PROG48-48U RH EC1 and XG50T06EN48U0. Its test figures match those of 3 other basic models. Those basic models are sold with Friedrich, Richmond, and Ruud as their brand names.

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.