Taco SR502-4 Switching Relay with Priority 2 Zone for HVAC Furnaces

Description

Product Overview

The Taco SR502-4 Switching Relay is engineered to meet the demanding requirements of modern HVAC furnace systems. Constructed from high‑grade copper contacts and a robust polymer housing, the relay offers reliable electrical performance even under continuous cycling conditions. Its compact footprint—measuring just 1 × 1 × 1 inch—and a weight of approximately 3 pounds make it suitable for tight enclosures where space is at a premium. The device features a built‑in priority circuit that ensures critical heating zones receive power before secondary zones, optimizing energy use and maintaining indoor comfort. Designed for a 120 V AC supply, the SR502-4 supports a maximum load of 15 amps, providing ample capacity for most residential and light‑commercial furnace applications. The relay is manufactured in the United States, adhering to strict quality‑control standards that guarantee long‑term durability and consistent performance throughout its service life.

Usage

This switching relay is intended for use in furnace control panels, particularly in systems that require zone‑based heating distribution. It excels in residential homes equipped with multi‑zone HVAC setups, as well as in small commercial buildings where precise temperature regulation across different areas is essential. The priority function allows the primary heating zone to activate first, reducing the time required to reach desired temperatures in the most critical spaces. Installation is straightforward: the relay mounts directly onto a standard DIN rail, and its terminal connections are clearly labeled for easy wiring to the furnace control board and zone valves. The device operates efficiently in a temperature range from -20 °C to +70 °C, making it suitable for both indoor and semi‑outdoor installations where ambient conditions may vary. Technicians appreciate the relay’s clear markings and the inclusion of a built‑in LED indicator that provides visual confirmation of relay activation, simplifying troubleshooting and routine maintenance.

Why Choose Us

Choosing the Taco SR502-4 means selecting a product backed by decades of industry experience and a reputation for reliability. Taco, a leading manufacturer of HVAC control components, designs its products with a focus on longevity, safety, and performance. The SR502-4 benefits from rigorous testing procedures, including thermal cycling and electrical endurance tests, ensuring it can withstand the harsh demands of continuous furnace operation. Because the relay is produced in the United States, customers receive a product that complies with North American safety standards such as UL and CSA certifications. Additionally, Taco provides comprehensive technical support and a responsive warranty service, giving installers confidence that any issues will be addressed promptly. The combination of high‑quality materials, precise engineering, and dedicated after‑sales assistance makes the SR502-4 a cost‑effective solution that reduces downtime and maintenance costs over the lifespan of the HVAC system.

Key Features

• Priority operation ensures primary heating zones receive power first, improving comfort and energy efficiency.
• Compact 1 × 1 × 1 inch size fits easily into crowded control panels without sacrificing performance.
• Durable copper contacts and reinforced polymer housing provide long‑term reliability under continuous cycling.
• Easy DIN‑rail mounting and clearly labeled terminals simplify installation and reduce wiring errors.
• Backed by Taco’s U.S. manufacturing quality and responsive customer support for peace of mind.

FAQ

What type of furnace systems is the SR502-4 compatible with?

The SR502-4 is compatible with most residential and light‑commercial forced‑air furnaces that operate on a 120 V AC supply and require zone control. It works with standard zone valves and can be integrated into existing thermostat wiring schemes without major modifications.

How does the priority function affect heating performance?

The built‑in priority circuit directs power to the primary heating zone before secondary zones. This means the most critical area of a building receives heat first, reducing overall warm‑up time and improving occupant comfort while optimizing fuel consumption.

Can the relay be used in outdoor or semi‑outdoor installations?

Yes. The SR502-4 is rated for operation in temperatures ranging from –20 °C to +70 °C, making it suitable for outdoor control panels or semi‑outdoor environments where temperature fluctuations are common.

What warranty does Taco provide for this relay?

Taco offers a limited one‑year warranty covering defects in materials and workmanship. During this period, any faulty unit can be returned for repair or replacement, and technical assistance is available to help resolve installation or performance questions.

Is professional installation required?

While the SR502-4 is designed for straightforward installation, it is recommended that a qualified HVAC technician perform the wiring and mounting to ensure compliance with local electrical codes and optimal system performance.