components described in subsection (c)(3)(C) by any taxpayer for any taxable year, the credit allowed under this section with respect to such amounts for such year shall not exceed the lesser of— (i) the excess (if any) of $500 over the aggregate credits allowed under this section with respect to such amounts for all prior taxable years ending after December 31, 2020, or (ii) $250 for each exterior door. (3) Limitation on residential energy property expenditures The credit allowed under this section by reason of subsection (a)(2) shall not, with respect to an item of property, exceed— (A) in the case of property described in subparagraph (A), (B), or (C) of subsection (d)(3), $600, (B) for the case of property described in subparagraph (D) of subsection (d)(3), $400, (C) in the case of a hot water boiler, $600, and (D) in the case of a furnace, an amount equal to the sum of— (i) $300, plus (ii) if the taxpayer is converting from a non-condensing furnace to a condensing furnace, $300. . (e) Standards for energy efficient building envelope components Section 25C(c)(2) is amended by striking meets— and all that follows through the period at the end and inserting the following: meets— (A) in the case of an exterior window, a skylight, or an exterior door, applicable Energy Star program requirements, and (B) in the case of any other component, the prescriptive criteria for such component established by the 2018 IECC (as such term is defined in section 45L(b)(5)). . (f) Roofs not building envelope components Section 25C(c)(3) is amended by adding and at the end of subparagraph (B), by striking , and at the end of subparagraph (C) and inserting a period, and by striking subparagraph (D). (g) Advanced main air circulating fans not qualified energy property (1) In general Section 25C(d)(2)(A) is amended by adding or at the end of clause (i), by striking , or at the end of clause (ii) and inserting a period, and by striking clause (iii). (2) Conforming amendment Section 25C(d) is amended by striking paragraph (5) and