Caleffi ZVR103 Relay

The Caleffi ZVR103 is a high-performance 3-zone valve relay designed for professional contractors managing multi-zone hydronic heating systems. Engineered for seamless integration, the ZVR103 serves as a direct technical replacement for the HPZC103, providing a robust interface between low-voltage 2, 3, and 4-wire thermostats and boiler equipment. This hydronic zone valve controller features a standard 40 VA transformer, which is field-expandable to 80 VA to accommodate higher load requirements. Professional installers benefit from the Z-oneLink technology, allowing for virtually unlimited zone expansion by connecting additional ZVR or ZSR series units via a simple 3-wire communication link. The diagnostic front panel LED indicators allow for rapid troubleshooting of zone calls and pump status at a glance. Equipped with heavy-duty sealed relays and an automatic resettable fuse, this control manages 120 VAC system, secondary, and priority pumps, ensuring reliable operation of DHW priority zones with a built-in 1-hour timeout feature for system protection and consistent efficiency.

• Direct Replacement: Fully compatible drop-in switch for the HPZC103, minimizing downtime during system upgrades or repairs.
• Advanced Connectivity: Z-oneLink allows installers to expand to an unlimited number of zones using a master/slave configuration.
• Priority Management: Selectable Zone 1 priority with a 1-hour safety timeout ensures domestic hot water demands are met without long-term heating interruption.
• Reliable Protection: Features an automatic resettable fuse on the 24V circuit to protect the internal transformer from localized shorts.
• Contractor-Friendly Wiring: Large screw terminals and dual-labeled (R,W,C / T,T,COM) connections streamline multi-zone hydronic control installation.

Is the Caleffi ZVR103 compatible with smart thermostats?
Yes, the Caleffi ZVR103 is compatible with 2, 3, and 4-wire low-voltage thermostats, including power-stealing models and those requiring a C-terminal common connection.

How do I expand the system beyond three zones?
You can bridge additional Caleffi zone relays using the Z-oneLink communication terminals. One unit is set as the Master, and subsequent units are configured as Slaves via onboard DIP switches.

Can I use this relay for a Domestic Hot Water (DHW) priority setup?
Absolutely. Zone 1 is designed for priority operation. When the priority DIP switch is engaged, a call for heat on Zone 1 will temporarily deactivate other zones to ensure maximum heat delivery to the DHW tank or priority loop.

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Disclaimer: While we strive for 100% accuracy, product data and specifications are subject to change. Please contact our team to confirm compatibility or technical details before purchasing.