Lennox 37J56 Circuit Breaker Switch

The Lennox 37J56 Circuit Breaker Switch (also identified as 37J5601) is an OEM-grade fuseholder-type thermal circuit breaker engineered for high-precision overcurrent protection in residential and commercial HVAC systems. Rated for 3 Amps at 250V, this single-pole thermal breaker serves as a critical safety component, protecting transformers (T1) and control boards from electrical damage. Designed with a robust panel-mount housing, it features a push-to-reset manual interface that allows technicians to quickly restore power after an overcurrent event without replacing fuses. This OEM Lennox part is a direct cross-reference for older models including 10K63 and 10K6301, and is compatible with Allied, Armstrong, Ducane, and Concord furnace and air handler equipment. Its 50/60 Hz compatibility and compact 0.05 lb build ensure a seamless fit into existing control panels, maintaining line-voltage integrity and preventing downtime caused by localized circuit faults.

• OEM Standards: Ensures exact electrical specifications and fitment for Lennox furnace, heat pump, and air handler control circuits.
• Thermal Overload Protection: Provides reliable thermal circuit breaker performance to safeguard expensive components like SureLight ignition boards and blowers.
• User-Friendly Reset: Features a manual push-button reset, eliminating the need for 3-amp glass fuses and simplifying field troubleshooting.
• Broad Compatibility: Replaces factory part numbers 37J5601 and 10K63, making it a versatile stocking item for service trucks.
• Industrial Durability: Rated for 250V AC applications, providing high-voltage tolerance for diverse electrical environments.

• Can the 37J56 be used in both 120V and 240V systems? Yes, its 250V rating makes it suitable for standard HVAC line voltage applications, provided the load does not exceed 3 Amps.
• Is the Lennox 37J5601 the same as the 37J56? Yes, these part numbers are technical equivalents and represent the same physical component.
• Why does my 3-amp thermal breaker keep tripping? Frequent tripping often indicates a downstream short in the transformer, a failing blower motor, or a compromised wire harness that exceeds the 3A threshold.

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.