Replacement Relay

The Lennox 66C67 is a 24V DPDT electromagnetic relay manufactured by Zettler Controls (model ZC90340-01) and engineered specifically for HVAC applications in residential and light commercial systems. This dual-pole, double-throw relay serves as a critical switching component for furnaces, air handlers, and blower systems, delivering reliable performance in demanding heating and cooling environments. Operating on 24V coil voltage at 50/60 Hz frequency, this relay is designed for seamless integration with Lennox HVAC equipment and compatible control systems. The unit features robust contact ratings across multiple voltage configurations: 125 VAC (82.8 AMP LRA, 13.8 AMP FLA), 208 VAC (45.6 AMP LRA, 7.6 AMP FLA), 250 VAC (41.4 AMP LRA, 6.9 AMP FLA), and 277 VAC (36 AMP LRA, 6 AMP FLA), with resistive load capacity rated at 15 AMP at 277 VAC. These specifications ensure dependable switching performance across typical commercial and residential electrical installations. Compact in design with dimensions of 1.95 inches in height and 5.35 inches in length, this relay offers straightforward installation in control cabinets and system panels. The electromagnetic construction provides consistent, repeatable switching action essential for precise HVAC operation and climate control accuracy. This replacement component is ideal for technicians, contractors, and facility managers requiring authentic Lennox-compatible relay switches for system maintenance, upgrades, or repairs. Its industrial-grade construction ensures extended service life and minimal downtime in critical heating and cooling applications.