Taco SR503-EXP

The Taco SR503-EXP is a 3 Zone Switching Relay for circulators with priority control and three powerports, built to simplify hydronic heating installations.

This compact module manages up to three independent zones, prioritizing one zone when demand requires it to optimize boiler efficiency and comfort. Its robust design supports safe operation, easy wiring, and long-term reliability in both residential and light commercial settings.

It supports efficient zone control, with easy wiring and reliable switching, compatible with other Taco components and standard circulator motors. Built-in protection and clear labeling help technicians install quickly and troubleshoot easily.

• Three powerports for flexible wiring and independent zone distribution
• Priority control guarantees critical zones receive heat first during high demand
• Three-zone switching with smooth transitions and reliable operation
• Durable enclosure suitable for residential or light commercial use
• Easy wiring with clear terminals and compatibility with standard circulator motors

Designed for radiant floor, baseboard, or central heating systems, the SR503-EXP delivers consistent temperatures across zones while reducing energy waste and improving overall comfort.