What is the difference between the T4398B1029 and the T4398B1029/U model

Versatile Application: Rated for both hot water and low-pressure steam

and R-407C refrigeration cycles

which is standard for most two-story residential systems

Carrier LH33WZ003 Flame Sensor Electrode Els PW 17895 What is the difference betweenThe Carrier LH33WZ003 Flame Sensor Electrode is a critical diagnostic and safety component designed for precise rectification in Carrier, Bryant, and Payne gas fired furnaces. This HVAC flame sensor replacement utilizes a high grade Kanthal metal rod to withstand the intense thermal stress of the burner assembly while maintaining consistent microamp signals to the integrated furnace control (IFC). When performing a furnace flame sensor cleaning or