New DOE Minimum
Efficiency Standards
The Department of Energy (DOE) sets national minimum energy efficiency standards for commercial and consumer (residential) water heaters.
All water heater manufacturers will be required to meet new minimum efficiency standards for both commercial applications by October 2026 and residential applications by May 2029.
American Water Heaters is committed to leading our industry in compliance.
2026 Commercial Water Heater Regulatory Requirements
The Department of Energy’s (DOE) new minimum efficiency standards for commercial water heaters will go into effect on October 6, 2026. These new regulations are part of DOE’s efforts to reduce overall energy consumption in the United States. These changes will present new complexities, but American Water Heaters is prepared for the transition.
The new standards will require that only high-efficiency (condensing) gas commercial water heaters can be manufactured or imported into the United States on and after October 6, 2026.
Gas Storage Standard
- Minimum Thermal Efficiency (TE) from 80% to 95%
Gas Instantaneous Standard
- Minimum TE from 80% to 96%
Gas Residential-Duty Storage Standard
- Uniform Energy Factor (UEF) of 0.9297
2029 Residential Water Heater Regulatory Requirements
The Department of Energy’s (DOE) new energy conservation standards for residential water heaters will go into effect on May 6, 2029. These new regulations are part of DOE’s efforts to reduce overall energy consumption in the United States.
The standards will require minor updates to gas-fired storage water heaters. Electric storage water heaters >35 gallons will require heat pump technology. The gas instantaneous (gas tankless) product category has been excluded from this rule and will be addressed by the DOE in a subsequent rulemaking.
The new energy efficiency levels will be required for all residential water heaters produced on and after May 6, 2029.
Gas-fired Storage
- <20 gallon: new standard to add UEF to these models – no current American products impacted
- ≥20 and ≤55 gallon: incremental UEF increase – atmospheric gas units will require the addition of a damper
- >55 and ≤100 gallon: no change
- >100 gallon: new standard to add UEF to these models
Gas-fired Instantaneous
- No change at this time
Electric Storage
- <20 gallon: new standard to add UEF to these models – compact units <20 gallon will have a UEF and FHR value added by the implementation date
- ≥20 and ≤35 gallon: no UEF change but will be limited to a max FHR of 50 gallons and a max temperature setting of 135°F o All nominal 40 gallon electrics are currently rated at 36 or 37 gallons and will have to be reduced to 35 gallons
- >35 and ≤120 gallon: requires Heat Pump Water Heater
- >75 gallon grid-enabled: no change
- >120 gallon: new standard to add UEF to these models – no current American products impacted
Electric Instantaneous
- <2 gallon: no change
- ≥2 gallon: new standard to add UEF to these models – no current American products impacted
Still Have Questions?
Why are the regulations changing for consumer (residential) water heaters?
In this final rule, DOE is adopting amended energy conservation standards for consumer water heaters. It has determined that the new and amended energy conservation standards for these products would result in significant conservation of energy, and are technologically feasible and economically justified.