3 Zone Pump Relay Control with priority

REHAU Pump Switching Relays SR503-4

SR series enhanced switching relays by REHAU are the best choice in the industry for zoning with circulators. Relay acts as intermediary between the boiler, 115V circulator pump(s) and 24V thermostat(s), allowing to control several pumps using a single thermostat, or, if the system has several zones, use multiple thermostats to control particular sets of one or more circulators.
REHAU switching relays are available in standard 3, 4 and 6-zone model.

Avantage:

It’s no longer necessary to open the box to troubleshoot the system. Externally visible lights show full functionality of the switching relay. The green light should always be on, indicating that power is connected. When the thermostat calls for heat, both the appropriate circulator and red indicating light is energized.

Features:

• External Indicator Lights
• Switchable Priority
• Simplified Wiring
• Fully Enclosed Snap-Out Relays
• Compact Design
• Fuse Protected
• 100% Factory Tested
• Isolated End Switch
• Contractor Friendly PC Board Layout
• Universal Thermostat Compatibility
• UL and CSA Approved
• 24 Volt Power Input or Output Terminal
• Made in the USA 

Installation Manual