Nordyne 917178A defrost control board for heat pumps (Nordyne and private-label Intertherm, Miller, Coleman, Frigidaire, Maytag), with a built-in 5-minute compressor anti-short-cycle time delay. Genuine OEM board; supersedes/cross-references older Nordyne numbers 624644, 624626, 621579, 624519 and 917012.
