10 C.F.R. § 431.86
Uniform test method for the measurement of energy efficiency of commercial packaged boilers.
Cite as 10 C.F.R. § 431.86 (2026)
(a)
Scope.
This section provides test procedures, pursuant to the Energy Policy and Conservation Act (EPCA), as amended, which must be followed for measuring the combustion efficiency and/or thermal efficiency of a gas- or oil-fired commercial packaged boiler.
(b)
Testing and Calculations.
Determine the thermal efficiency or combustion efficiency of commercial packaged boilers by conducting the appropriate test procedure(s) indicated in Table 1 of this section.
Table 1—Test Requirements for Commercial Packaged Boiler Equipment Classes
Equipment category
Subcategory
Certified rated input
Btu/h
Standards efficiency metric
(§ 431.87)
Test procedure
(corresponding to
standards efficiency
metric required
by § 431.87)
Hot Water
Gas-fired
≥300,000 and ≤2,500,000
Thermal Efficiency
Appendix A, Section 2.
Hot Water
Gas-fired
>2,500,000
Combustion Efficiency
Appendix A, Section 3.
Hot Water
Oil-fired
≥300,000 and ≤2,500,000
Thermal Efficiency
Appendix A, Section 2.
Hot Water
Oil-fired
>2,500,000
Combustion Efficiency
Appendix A, Section 3.
Steam
Gas-fired (all*)
≥300,000 and ≤2,500,000
Thermal Efficiency
Appendix A, Section 2.
Steam
Gas-fired (all*)
>2,500,000 and ≤5,000,000
Thermal Efficiency
Appendix A, Section 2.
>5,000,000
Thermal Efficiency
Appendix A, Section 2.
OR
Appendix A, Section 3 with Section 2.4.3.2.
Steam
Oil-fired
≥300,000 and ≤2,500,000
Thermal Efficiency
Appendix A, Section 2.
Steam
Oil-fired
>2,500,000 and ≤5,000,000
Thermal Efficiency
Appendix A, Section 2.
>5,000,000
Thermal Efficiency
Appendix A, Section 2.
OR
Appendix A, Section 3. with Section 2.4.3.2.
* Equipment classes for commercial packaged boilers as of July 22, 2009 (74 FR 36355) distinguish between gas-fired natural draft and all other gas-fired (except natural draft).
(c)
Field Tests.
The field test provisions of appendix A may be used only to test a unit of commercial packaged boiler with rated input greater than 5,000,000 Btu/h.
[81 FR 89305, Dec. 9, 2016]
- Cross-references to the CFR
- 431.87