the "/U" suffix simply denotes the retail-packaged universal version of the same Honeywell ignition cable

This genuine Reznor OEM part contains the 209165 relay and comprehensive instruction sheet for field installation

Proper installation involves verifying the L190-30F specifications to match the original equipment manufacturer’s requirements for airflow and heat rise safety

Technical Precision: Accurately manages start capacitor cutout based on back-EMF

Precise Thermal Control: Calibrated for 180°F cut-out and 160°F cut-in to maintain strict furnace safety parameters

Schneider Electric (Barber Colman) 2378-501 Relay Els PW 17895 the "/U" suffix simply denotesThe Schneider Electric (Barber Colman) 2378 501 Relay is a high performance pneumatic amplifying relay designed for proportional signal control in HVAC systems. Engineered as a Pneumodular component, this device provides a definitive 2: 1 amplifying function, doubling the input signal pressure to the branch line. This is essential for contractors managing larger actuators or terminal units that require higher pressure than the standard controller