Description
SR503-4 Taco 3 zone control,
Taco switching relays combine
clearly-labeled PC board
layouts with advanced
features that allow you to
completely customize your
system, and whether you're
using basic priority
switching, Taco plug-In
PowerPort cards or add-on
power controls, tailoring the
system has never been easier,
external indicator lights
give you instant diagnostic
feedback, making service
calls or new installation
start-ups a snap, all
switching relays are UL
listed, use standard "ice
cube" replaceable relays and
are compatible with
conventional and programmable
thermostats, for larger jobs,
switching relays can be
expanded up to 20 zones with
priority, with the exclusive
Taco PowerPort plug-In cards,
you can easily add such
features as post purge,
priority protection and pump
exercise, any expandable
switching relay can also
interface with the boiler
reset control and injection
mixing add-on power controls,
mix-and-match as needed to
customize the system, 2 zone
control, 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, extended
3 year warranty, made in the
USA