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64 FR 54141, Oct. 5, 1999, unless otherwise noted.
70 FR 60418, Oct. 18, 2005, unless otherwise noted.
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At 90 FR 43371, Sept. 9, 2025, as required by the Congressional Review Act and Pub. L. 119-8, the Department of Energy removed the amendments to several sections in part 431 made effective on Dec. 23, 2024, at 89 FR 91163, Oct. 9, 2024. As of Sept. 9, 2025, the affected sections reverted to the Dec. 22, 2024 version.
A unit heater manufactured on or after August 8, 2008, shall:
(a) Be equipped with an intermittent ignition device; and
(b) Have power venting or an automatic flue damper. An automatic vent damper is an acceptable alternative to an automatic flue damper for those unit heaters where combustion air is drawn from the conditioned space.
[70 FR 60418, Oct. 18, 2005, as amended at 71 FR 71374, Dec. 8, 2006]