Taco SR503-4 3-Zone Switching Relay w/ Priority - New - $185 (Porter Square)

Taco SR503-4 3-Zone Switching Relay w/ Priority - New 1 thumbnail

condition: new

make / manufacturer: Taco

model name / number: SR503-4

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New, never-installed Taco SR503-4 3-zone switching relay with priority for hydronic heating systems.

Purchased for a project but never used. The box has been opened, but the relay has never been installed or wired.

* 3 zones with Zone 3 priority
* 120 VAC
* 15A maximum total load
* Isolated end switch
* Original box and packaging
* Original instruction sheet
* Includes thermostat resistor shown in photos

The relay, terminals, mounting holes and knockouts are all in unused condition. The original box has some wear from storage.

post id: 7975012815

posted: 2026-09-29 14:38

updated: 2026-10-04 13:13

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Taco SR503-4 3-Zone Switching Relay w/ Priority - New -...

New, never-installed Taco SR503-4 3-zone switching relay with priority for hydronic heating systems. Purchased for a project but never used. The box has been opened, but the relay has never been...