Caleffi hydronic heating zone controls

Caleffi’s line of hydronic heating zone controls — the ZSR101, ZSR and ZVR series — feature heavy-duty sealed relays for quiet operation; large screw terminals for ease of wiring and on-board ground terminals; and are compatible with two-, three- and four-wire thermostats or other low-voltage controllers with switching action. The ZSR pump controller and ZVR valve controller models are expandable to an unlimited number of zones using simple three-wire connection between controls.