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dead firing

American  

noun

  1. firing of a furnace or boiler at less than normal operating temperature in order to maintain conditions desirable during a period of idleness.

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Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.