Lennox 25G43 Time Delay Relay

The Lennox 25G43 Time Delay Relay is a critical component for managing sequence-of-operation timing in residential and commercial HVAC units. Also identified by part number 25G4301, this 24V AC time delay relay is engineered to prevent short-cycling and coordinate staged cooling demands. In modern Lennox HVAC systems, this specific relay-on-make and delay-on-break timer ensures independent component timing, allowing for precise control of fan circuits and compressor delay functions. With its 0.75 Amp rating and compatibility with 50/60 Hz frequencies, the 25G43 provides the necessary timing intervals to optimize system performance and equipment longevity. It functions effectively in retrofit applications where a third cooling stage is added, allowing for a user-selectable stage-up timer. This OEM Lennox replacement part is built for the demanding environments of the HVACR industry, ensuring that gas valve assemblies and balanced terminals operate in the exact sequence required for safe and efficient heating and cooling cycles.

• Direct OEM Replacement: Seamlessly replaces Lennox 25G4301 and Littlefuse SSAC CT30S1 models, maintaining original system specifications.
• Prevents Short-Cycling: Protects high-cost components like compressors by enforcing a 30-second delay-on-break interval.
• Versatile Application: Ideal for fan control circuits, defrost cycles, and refrigeration units requiring precise 24V timing control.
• Enhanced Safety: Controls the operation of gas furnaces and HRV/ERV systems, ensuring components satisfy thermostat demands before shutting down.
• Simplified Installation: Standard 2-terminal configuration allows for quick integration into existing Lennox control boards.

Is the Lennox 25G43 compatible with older 25G4301 units?
Yes, the Lennox 25G43 is technically identical to the 25G4301 and can be used as a direct 1:1 replacement in all Lennox furnace and AC systems.

What is the standard delay timing for this relay?
This HVAC delay timer typically features a 1-second delay-on-make and a 30-second delay-on-break to coordinate multi-stage cooling and protect the system from rapid cycling.

Can this relay be used for 120V applications?
No, this specific model is designed for 24V AC control circuits. Always verify the input voltage at the transformer or control board before installation.

Disclaimer: While we strive for 100% accuracy, product data and specifications are subject to change. Please contact our team to confirm compatibility or technical details before purchasing.