Lennox 78H74 Limit Switch 322838-753 Engineered for compatibility with "E"

Engineered for compatibility with "E" series main valves

preventing catastrophic shell and tube damage

The industrial burner sleeve ensures consistent airflow dynamics and thermal distribution

The FILN05-S is rated for ambient temperatures ranging from 32° to 200°F

Lennox 78H74 Limit Switch 322838-753 Engineered for compatibility with "E"The Lennox 78H74 is a critical OEM L185F limit switch designed for precision thermal protection in residential and commercial Lennox heating systems. As a primary safety control, this high limit switch monitors internal heat exchanger temperatures and is engineered to open the electrical circuit if the ambient temperature reaches the L185F set point. This rapid response prevents internal overheating and ensures the system operates within safe HVAC