maintaining the pressure drop characteristics required for high-efficiency cooling

ensuring backward compatibility with older solenoid valve assemblies

and fans within VAV boxes and air handlers

handling demanding electrical loads without external relays

York S1-373-23870-001 Defrost Control Kit Refrigerant maintaining the pressure drop characteristicsEnsure reliable evaporator performance in sub freezing conditions with the York S1 373 23870 001 Defrost Control Kit. This genuine Source1 OEM replacement, part of the YorkGuard VI sub brand, is engineered specifically for EFH, EEB, and ECS series heat pumps. As a veteran grade solution for heat pump defrost board failures, this kit replaces legacy part numbers including 1157 83 550B and 37323870001. It utilizes advanced time temperature initiation