Taco TACO-SR502-2 2 Zone Switching Relay 120V

Product Description

The TACO TACO-SR502-2 is a 2-zone switching relay designed for hydronic heating zoning applications. Operating on 120 volts AC, this relay panel controls zone valves or circulators across two independent zones, allowing precise heat distribution in residential and light commercial hydronic systems. The board layout uses clearly labeled terminals that reduce wiring errors during installation. External indicator lights provide real-time diagnostic feedback so technicians can verify zone status without a meter. Standard ice cube replaceable relays keep serviceability straightforward. The unit is UL listed and works with both conventional and programmable thermostats.

The TACO-SR502-2 is suited for residential hydronic heating systems where two heating zones require independent control. Typical installations include baseboard hot water systems, radiant floor heating, and fan coil applications split across two zones. The relay accepts low-voltage thermostat signals and switches 120V power to zone valves or circulators accordingly. For larger projects, this unit is part of the TACO switching relay family, which supports expansion up to 20 zones with priority. It can also interface with Boiler Reset Controls and Injection Mixing Add-On Power Controls using TACO PowerPort Plug-In Cards for features such as post purge, priority protection, and pump exercise.

Key Features

• Controls 2 independent hydronic heating zones from a single panel
• 120V AC input with clearly labeled PC board layout for fast, accurate wiring
• External indicator lights provide instant zone-status diagnostics
• Standard ice cube replaceable relays simplify field servicing
• Compatible with conventional and programmable thermostats
• Expandable to 20 zones with priority via TACO switching relay system
• Supports TACO PowerPort Plug-In Cards for post purge, priority protection, and pump exercise

Compatibility

Compatible with conventional and programmable thermostats. Designed for use within the TACO switching relay system and supports interface with TACO Boiler Reset Controls and Injection Mixing Add-On Power Controls via TACO PowerPort Plug-In Cards.

Installation Notes

Installation should be performed by a licensed HVAC or plumbing technician familiar with hydronic heating systems. Disconnect and lock out all power to the system before wiring the relay panel. Low-voltage thermostat wiring and line-voltage connections must be kept separated and routed according to applicable NEC requirements. Verify all zone valve or circulator loads are within the relay contact ratings before energizing the system.

Technical Specifications

• Application: Zoning
• Number of Zones: 2
• Voltage: 120V AC
• Width: 10.25 inches
• Height: 6.75 inches
• Depth: 2.75 inches

Standard Information

• Brand: TACO
• Manufacturer Part Number: TACO-SR502-2