Designed with a 1/2-inch bore and a fixed hub

while a "wet" reading signals that a drier change-out is required to prevent acid buildup and thermal expansion valve freeze-ups

5-inch furnace cabinets and air handler units

A 4-way valve provides an additional port

OEM Compatibility: Eliminates the need for field modifications

Lochinvar & A.O. Smith 100111904 Board 319847-401 Designed with a 1/2-inch boreThe Lochinvar & A. O. Smith 100111904 Power Distribution Board is a critical OEM replacement part engineered for high performance commercial water heating systems and boiler controls. As a primary voltage distribution center, this board manages the complex electrical pathways necessary for heating cycle regulation and robust system diagnostics. Designed to meet the precise tolerances of Lochinvar and A. O. Smith hydronic systems, it facilitates