Caleffi’s ZVR Series of controls is for zoning using zone valves. Up to six valves (model dependent) — along with a system pump, secondary pump(s) and primary pump — can be operated. Zone priority is selectable with a one-hour time-out feature. System pump status (on/off) during priority also is selectable. Replaceable snap-fit 40 VA transformer is standard for three- and four-zone models — expandable to 80 VA with a second transformer. The six-zone model has two 40 VA (80 VA) transformers.  .