There is no functional difference between these parts

Key Benefits for Technicians Full Internal Restoration: Includes both check modules and the complete relief valve assembly for a total system overhaul

This dual-setpoint pressure switch features an automatic reset function

Low Voltage Reliability: Engineered for 24VAC control circuits

Lennox 19M54 Board Kit Els PW 29614 There is no functional differenceThe Lennox 19M54 Board Kit is a critical gas furnace ignition control replacement designed to upgrade older GCI 3, RAM 3MC5, and EGC 2 platforms to the more reliable GCI 3A (23L53) ignition control board. This comprehensive Lennox 19M54 conversion kit is essential for technicians servicing LF24 and LD24 Series unit heaters and duct furnaces. It ensures precise intermittent pilot ignition sequencing and system diagnostics, resolving common field issues