The Taco SR503-5 is an expandable 3-zone switching relay that operates on a 120V input with a maximum combined load of 15A.  This features a compact enclosure measuring 12-1/2" X 8-1/2" X 2-5/8".  It is UL-listed ensuring safety compliance.

Includes front-mounted diagnostic indicator lights for quick system status assessments and a switchable priority function to ensure critical zones receive heat when needed.  Designed for simplified wiring, featuring a contractor-friendly PC board layout that makes installation straightforward.  Additional benefits include built-in priority protection, premium sealed relays, fuse protection, an isolated end switch, universal thermostat compatibility, and a 100% factory-tested guarantee.

This switching relay is ideal for residential and light commercial hydronic heating systems requiring efficient management of up to three zones.  It is particularly suited for applications where zone prioritization is crucial, such as:

Upgrade your heating system with the Taco SR503-5 for enhanced efficiency, reliability, and ease of installation!