Code of Federal Regulations > Title 10 > Chapter II > Part 431 > Subpart G - Subpart G—Commercial Water Heaters, Hot Water Supply Boilers and Unfired Hot Water Storage Tanks

U.S. Code of Federal Regulations

Regulations most recently checked for updates: Dec 14, 2025

TEST PROCEDURES

§ 431.105 - Materials incorporated by reference.

§ 431.106 - Uniform test method for the measurement of energy efficiency of commercial water heating equipment.

§ 431.101 - Purpose and scope.

§ 431.102 - Definitions concerning commercial water heaters, hot water supply boilers, unfired hot water storage tanks, and commercial heat pump water heaters.

ENERGY CONSERVATION STANDARDS

§ 431.110 - Energy conservation standards and their effective dates.

Appendix Appendix A - Appendix A to Subpart G of Part 431—Uniform Test Method for the Measurement of Thermal Efficiency and Standby Loss of Gas-Fired and Oil-Fired Storage Water Heaters and Storage-Type Instantaneous Water Heaters

Appendix Appendix B - Appendix B to Subpart G of Part 431—Uniform Test Method for the Measurement of Standby Loss of Electric Storage Water Heaters and Storage-Type Instantaneous Water Heaters

Appendix Appendix C - Appendix C to Subpart G of Part 431—Uniform Test Method for the Measurement of Thermal Efficiency and Standby Loss of Gas-Fired and Oil-Fired Instantaneous Water Heaters and Hot Water Supply Boilers (Other Than Storage-Type Instantaneous Water Heaters)

Appendix Appendix D - Appendix D to Subpart G of Part 431—Uniform Test Method for the Measurement of Standby Loss of Electric Instantaneous Water Heaters (Other Than Storage-Type Instantaneous Water Heaters)

Appendix Appendix E - Appendix E to Subpart G of Part 431—Uniform Test Method for the Measurement of Energy Efficiency of Commercial Heat Pump Water Heaters