Taco®, ZVC403-4, Zone Valve Controls, 3, 24 V

Taco ZVC403-4 Three-Zone Valve Control Module – 24V Operation with End Switch Integration

The Taco ZVC403-4 is a three-zone valve control panel designed for hydronic heating systems using 2-, 3-, or 4-wire zone valves. This control simplifies system wiring and provides reliable, centralized management of multiple heating zones. It includes two isolated end switches for boiler and circulator activation and is equipped with built-in transformer power for 24V zone valve operation.

This control module features front-mounted LED indicators for each zone, enabling quick diagnostics during installation and service. Screw terminal connections, a field-replaceable transformer, and priority zone selection further streamline configuration for professional contractors.

Product Features

• Three-Zone Capacity: Controls up to 3 individual heating zones with 2-, 3-, or 4-wire zone valve compatibility
• Dual Isolated End Switches: Allows separate control of both boiler and system pump operation
• LED Indicators: Diagnostic lights display thermostat call, valve actuation, and end switch status
• Priority Zone Capability: One zone can be set as priority with automatic time-out override
• Built-in Transformer: Provides 24V power for zone valves; field replaceable for serviceability
• Fuse Protection: Fully fuse-protected outputs for zone valve safety and circuit integrity
• Enclosure: Hinged metal cover for secure, accessible field wiring

Technical Specifications

• Model: ZVC403-4
• Zones: 3
• Voltage Input: 120 VAC
• Transformer Output: 24 VAC
• End Switches: Two sets of dry contacts, rated 24 VAC
• Mounting: Wall mountable enclosure with integrated knockouts
• Certifications: UL Listed

Installation Considerations

The ZVC403-4 is designed for efficient field installation with clearly labeled terminals and contractor-focused PC board layout. Wiring errors are reduced due to intuitive labeling and status indication. Although the module is straightforward for experienced professionals, installation should be performed by a licensed technician to ensure code compliance and correct system integration.

Application Notes

This control is commonly used in hydronic systems with baseboard, radiant, or panel heating applications where multiple zones are required. The ZVC403-4 interfaces with conventional or programmable thermostats and supports both power open/power close and power open/spring return zone valve designs.