Rheem Commercial Water logo

What you need to know

The Department of
Energy’s New
Conservation Standards

Rheem Commercial water is here to help you navigate through the upcoming changes to enable you to make choices that fit your long-term needs.

DOE seal

Looking Ahead to 2026

We’ve gathered the facts and removed the complexities behind the new standards to prepare you for the new changes scheduled to take effect on October 6, 2026.

The new standards are a significant step towards energy efficiency impacting commercial gas water heaters.

Summary of the Rule

Commercial gas water heaters manufactured on and after October 6, 2026, must meet the new minimum DOE energy conservation standard, as outlined below:


Current Standards

Amended Standards

Gas-Fired Storage

TE = 80%

SL = Q/800 + 110(Vr)1/2

TE = 95%

SL = 0.86*(Q/800 + 110(Vr)1/2)

Gas-Fired Instantaneous

TE = 80%

SL (≥10gal) = Q/800 + 110(Vr)1/2

TE = 96%

SL (≥10gal) = Q/800 + 110(Vr)1/2

Residential-Duty Commercial Gas-Fired Storage

Medium Draw Pattern


High Draw Pattern


Medium Draw Pattern


High Draw Pattern


*TE=Thermal Efficiency (%), SL=Standby Loss (Btu/h), UEF=Uniform Energy Factor, Q=Input Rate (Btu/h), Vr=rated storage volume.

For more information about the new ruling, visit Energy Conservation Program: Energy Conservation Standards for Commercial Water Heating Equipment.

What to Expect:

c02 cloud with arrow pointing down

Lower Carbon Emissions

According to the DOE, the adoption of these standards will reduce carbon emissions by 38 million metric tons between 2026 and 2055. This is equivalent to the average annual emissions of approximately 37 coal-fired power plants.

a bill and a moneybag

Reduced Utility Bills

Businesses may experience lower utility bills.

side by side water heaters

Phase out of Non-Condensing Water Heaters

Non-condensing water heaters, which allow excess heat to escape through venting are targeted for phase out.

person with exclaimation point over their head between tools and money

Installation Complexity

Replacing older water heaters will most often mean replacing the venting.

High-Efficiency Products and Training

As the industry adapts to these changes, Rheem Commercial Water is with you Every Step of the Way with products and training to help you through the transition.

Compliant Product Solutions

High-efficiency condensing products capture and utilize the latent heat energy from the combustion process that would otherwise be wasted, resulting in improved overall efficiency. Rheem Commercial Water offers the following high-efficiency products that are compliant with the new regulations.

DOE seal