Ensure the threaded nut is snug and the mica insulation remains intact

Universal Refrigerant Compatibility: Supports a comprehensive range of traditional and A2L refrigerants including R410A

while the plastic cap is for protection during installation

Common Questions: Can this relay replace the 42-19736-04

This part is essential for maintaining CSA certified safety standards in natural gas or LP systems where down-stream controls require consistent

Lennox 99K63 Rollout Switch Ensure the threaded nut isThe Lennox 99K63 Rollout Switch is a critical safety component designed for precise thermal monitoring in residential and commercial gas furnaces. Engineered as a manual reset rollout switch, this part is calibrated to actuate at 250 degrees F (+ 12F), immediately interrupting the burner circuit if it detects flame rollout or excessive heat concentrations outside the combustion chamber. This OEM Lennox replacement part, also identified by part number