Reznor 97479 Relay

The Reznor 97479 Time Delay Relay is a critical field-service component designed for precise sequence control in Reznor gas-fired unit heaters. Engineered for high-duty cycle applications, this DPDT (Double Pole Double Throw) relay manages the timing of the blower motor and inducer fan, ensuring the heat exchanger reaches optimal temperature before airflow begins and purging residual heat during the post-purge cycle. Operating on a standard 24V control circuit, the 97479 prevents short-cycling and thermal stress on the equipment. This OEM Reznor replacement part is essential for maintaining the factory-specified firing sequence and HVAC system efficiency. For technicians performing furnace relay troubleshooting, the 97479 offers a direct-fit solution that eliminates the compatibility risks associated with universal timing boards. Its robust electrical contacts are rated for the inductive loads typical of industrial heating units, providing reliable timed delay switching in demanding commercial environments.

• Precise Timing Control: Ensures proper heat exchanger pre-heating and post-purge cooling to extend equipment lifespan.
• OEM Compatibility: Designed specifically for Reznor unit heaters, ensuring correct mounting footprints and terminal alignments.
• Versatile DPDT Configuration: Provides flexible switching options for both standard and multi-stage heating sequences.
• Industrial Build Quality: High-grade internal coils and contact points resist pitting and carbon buildup in high-use cycles.

Common HVAC Questions:

What are the symptoms of a failing Reznor 97479 relay?
Common signs include the blower motor failing to kick on after the burners ignite, the fan running indefinitely after the thermostat is satisfied, or the unit tripping on its high-limit switch due to a lack of airflow timing.

Can this time delay relay be used on other gas-fired heaters?
While functionally similar to other 24V delays, the 97479 is spec’d for Reznor’s internal wiring schematics. Using a non-OEM HVAC blower delay may require field modifications and could alter the safety timings of the unit.

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.