For technicians performing HVAC troubleshooting on York

but you should always verify the part number against your unit's specific parts list or wiring diagram

Technicians should verify airflow restrictions

This gasket is designed to withstand the high-pressure and high-temperature environments of hydronic heating systems

and Westinghouse gas furnaces

Lennox 79L55 Burner Orifice For technicians performing HVAC troubleshootingThe Lennox 79L55 is a precision engineered #42 burner orifice designed to manage fuel delivery within high efficiency gas furnaces. As a direct replacement for the Lennox 79L5501, this component is critical for maintaining the stoichiometric balance required for clean combustion. This #42 sizing is specifically calibrated to meter gas flow at the manifold, ensuring that the burner assembly receives the exact BTUs required for optimal thermal output