If you’re selecting a 24-volt HVAC relay, you want a model that reliably switches fans, compressors, and blowers without nuisance tripping. This guide highlights five practical options, suitable for typical residential and light commercial setups. Each product is explained with who it’s best for, why it’s a solid choice, and a quick caution to consider during selection. A concise buying table at the start helps you compare core specs at a glance.
| Product | Coil Voltage | Contact Form | Best For |
|---|---|---|---|
| 2PCS Electromagnetic Power Relay, MY2NJ | 24 VAC | DPDT | General HVAC control and DIN-rail installations |
| Supco 90370 General Purpose Relay | 24 V | SPST/SPDT options | Simple fan or accessory switching |
| 2 Pack 24V Fan Relay, SZRKRLA | 24 V | SPST | HVAC fan and blower control |
| Dreyoo 1 Pcs 24V Coil Contactor | 24 V | 2-pole | Higher load HVAC motors and compressors |
| 2nd Electromagnetic Power Relay, MY2NJ Variant | 24 VAC | DPDT | DIN-rail friendly AC/DC control |
2PCS Electromagnetic Power Relay, MY2NJ – DPDT 24 VAC
This DPDT 24 VAC relay is built for DIN-rail systems and offers 2NO/2NC contacts with an 8-terminal setup and a 10A contact rating. Best for general HVAC control tasks like compressor starters, fan circuits, or small pump controls. The LED indicator helps confirm coil activation at a glance. Choose this if you need a compact, DIN-rail compatible solution that fits standard electrical enclosures.
Who it’s best for: technicians wiring small-to-medium HVAC controls in residential or light commercial units requiring reliable DPDT switching. Why selected: strong DIN-rail compatibility and robust 24 VAC coil performance.
Caution: Ensure the enclosure has enough space for two relays and that wiring follows DIN-rail practices to avoid heat buildup.
Supco 90370 General Purpose Fan Relay
This general-purpose relay is designed for fan control and offers SPST-NO or SPDT variants suitable for simple fan or blower circuits. The 24 V coil makes it compatible with many thermostat and control boards. Best for straightforward fan control applications where a single switching path is sufficient. It’s a solid choice when a compact, low-cost relay is needed.
Who it’s best for: DIYers and installers seeking an economical, easy-to-wire fan control relay. Why selected: straightforward operation and flexible contact forms for common HVAC fan setups.
Caution: Check that the chosen variant (SPST-NO vs SPDT) matches your control logic to avoid miswiring the circuit.
2 Pack 24V Fan Relay, SZRKRLA
These isolation relays are designed for HVAC systems including air conditioning, furnaces, and blowers. They operate on 24-volt signals and emphasize stability, corrosion resistance, and longevity. Best for systems requiring reliable isolation between control circuitry and load side, especially in mixed metal environments. Avoid if you need a high-load relay in tight 24 VAC duty cycles and require superior mechanical robustness for continuous cycling.
Who it’s best for: installers seeking durable isolation relays that can handle multiple HVAC control points. Why selected: robust construction and broad compatibility across typical HVAC components.
Caution: While designed to last, verify 24 V control logic matches your control board outputs to ensure proper actuation.
Dreyoo 1 Pcs 24V Coil 40A Contactor
This 24V coil, 2-pole contactor supports high-load HVAC motor circuits with a 40A full-load capacity and 50A resistive load rating. It is UL508-listed and features hermetically sealed coil encapsulation for moisture resistance. Best for rooftop units or commercial-style HVAC installations where motor loads are substantial. Limitations include fixed mechanical footprint and need for proper lug connections.
Who it’s best for: professionals handling larger HVAC motors or systems that require solid switching of higher current loads. Why selected: high current capacity and reliability in harsh environments.
Caution: Ensure compatibility with your specific motor and that wiring terminals match the included lugs and connection points for secure installation.
MY2NJ 24 VAC DPDT Relay – 2nd Variant
This electromagnetic relay supports 24 VAC coils with a DPDT arrangement and 8 terminals, suitable for dual switching paths in control circuits. It is commonly used for motor, compressor, and fan controls that need two independent circuits actuated from a single coil input. Best for compact control panels where two separate loads share a control signal. Caution: verify the coil’s current draw fits your control board’s capability to avoid overloading the driver.
Dreyoo 1 Pack 24V Fan Relay (UL-Certified)
This 90-380 isolation relay is UL-certified for 24 VAC applications and designed to control fans, blowers, and related HVAC components. It emphasizes versatility across Goodman units and other equipment. Best for systems requiring UL certification as a mark of compliance and a reliable switch for everyday fan control. Caution: check unit compatibility, especially when integrating with older or non-standard furnace boards.
ClimaTek 24 Volt General Relay
This general-purpose ClimaTek relay replaces several older part numbers and is designed for durability in HVAC circuits. It is a solid option when you need compatibility with historical control panels. Best for updating aging equipment or replacing worn-out relays in standard HVAC control loops. Caution: confirm exact pinout and coil ratings to ensure a proper fit with existing sockets and boards.
Buying Guide: Key Considerations For 24V HVAC Relays
- Coil Voltage and Load: Ensure the coil voltage matches your control circuits (commonly 24 VAC) and that the contact rating supports the load (amperage and voltage) of the device you are switching.
- Contact Configuration: Choose DPDT for dual switching paths, SPDT for single path control, or SPST for simple on/off loads. Consider if isolation is needed between control and load circuits.
- Mechanical and Environmental Durability: Look for seals, insulation class, and ingress protection if the relay will face dust, moisture, or temperature extremes.
- Physical Footprint and Mounting: DIN-rail compatibility helps with organized panels; confirm space, terminal layout, and lug connections fit your enclosure.
- UL/CSA Certification: When applicable, certification can reflect compliance with safety standards for HVAC environments.
- Compatibility and Replacement: If replacing an existing part, verify part numbers, socket bases, and wiring diagrams to avoid mismatches.
Frequently Asked Questions
- What is a 24V HVAC relay used for?
– It switches load devices like fans, compressors, and blowers using a low-voltage control signal. - Why choose a DPDT relay over SPST?
– DPDT provides two independent switching paths, useful for controlling multiple components from one coil. - Do I need isolation relays in HVAC systems?
– Isolation relays protect control circuits from load-side transients and corrosion, especially in mixed-metal environments. - What should I check before buying a relay?
– Coil voltage, contact form, current rating, mounting method, and environmental suitability. - Are UL-listed relays necessary for residential installs?
– UL certification is advantageous for safety compliance and is often recommended for professional installations.
