the 1171901 serves as a direct OEM HVAC replacement part

technicians should use anti-static protection and verify all terminal connections are secure and free of oxidation before powering the system

This manual-handle valve is built to survive the rigors of field service

Smith water heater latches

and 100165916

Caleffi ZVR104 Relay 319852-301 the 1171901 serves as aThe Caleffi ZVR104 is a professional grade 4 zone valve relay designed for precise control of hydronic heating systems. Serving as a direct HPZC104 replacement, this multi zone controller manages up to four zone valves and features priority zoning functionality, allowing a single zone to be designated for domestic hot water (DHW) production. Engineered with a multi pin selectable priority option, the ZVR104 ensures that space heating loads are