Lennox 66J78 Limit Switch Els PW 17895 Always verify your specific model

Always verify your specific model number against the factory parts list

For ducts wider than 4 feet

Precise 3/16" I

This indicates the open temperature is 80°F and the close temperature is 31°F

Lennox 66J78 Limit Switch Els PW 17895 Always verify your specific modelExperienced HVAC contractors recognize the Lennox 66J78 Limit Switch as a critical safety component for maintaining furnace integrity and preventing heat exchanger damage. This OEM Lennox replacement part is a 36T series disc style control designed for High Limit or Secondary Rollout applications. It features a Normally Closed (NC) circuit that opens on temperature rise to interrupt the heating cycle if internal temperatures exceed safe operating