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

which is standard for most two-story residential systems

making it a drop-in Erie zone valve replacement for existing low-pressure steam and water systems

Does it matter which way the wires are connected

Often referenced by legacy part numbers PRS20020 and PRS20020K

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