External Indicator Lights, Universal replaceability, Snap-in PC Board Simplified Wiring, Fully Enclosed Snap-Out Relays, 100%Factory Tested Contractor Friendly PC Board Layout, Universal Thermostat Compatibility, UL and CSA Approved Extended 3 Year Warranty, Made in the USA External Indicator Lights

The Taco SR501 Switching Relay’s layout makes short work of any job. Its snap-in PC board easily replaces other single zone switching relays, without replacing the entire box. The single zone switching relay is UL and CSA listed, uses a standard ice cube replaceable relay and is compatible with conventional and programmable thermostats. External indicator lights provide instant diagnostic feedback, making a snap of service calls or new installation start-ups. Replaces the Honeywell R845A and similar relays.