Design, Installation and Control
For Cold Start Boiler Application (Left)
Operation:When any thermostat calls for heat, the appropriate circulating pump is energized and the isolated end switch (X and X) will start the boiler.
For Tankless Coil Boiler Application (Right)
Operation:When any thermostat calls for heat, the boiler will be enabled andappropriate circulating pump is energized when the boiler temperature is above the set low limit and low limit (ZC) dip switch is set to on.
ZC and ZR Terminals: Connect terminal ZC to ZC terminal on the aquastatcontrol. Connect ZR to ZR terminal on the aquastat control. Confirm polarity is consistent between boiler aquastat and switching relay.
Read more: Taco SR503-EXP-4, SR504-EXP-4,SR506-EXP-4, Expandable Switching Relay
Operation: When the thermostat calls for heat, the circulating pump is energized and the isolated end switch (X and X) will start the boiler.
Priority Operation: When the priority dip switch is set to ON and the zone is actuated, all other connected zoning panels will stop operation until the zone is satisfied. When the priority dip switch is set to OFF and the zone is actuated, all other connected zoning panels will operate independently.
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