the TX3N2 is strictly designed for R22 refrigerant

Built for durability in high-moisture environments

preventing the wide temperature swings common in standard on/off systems

identified as Hatcol 3693

This genuine Carrier replacement part functions as a critical thermal overload relay

Lochinvar & A.O. Smith 100277940 Board 30067439-890 the TX3N2 is strictly designedThe Lochinvar & A. O. Smith 100277940 Board is a critical low voltage connection board engineered for precision signaling in high efficiency heating systems. Specifically designed for the Knight KH055 285 fire tube boilers, this OEM replacement part serves as the central communication interface between the main controller and auxiliary system components. As a veteran technician knows, maintaining signal integrity in commercial water heating