Industrial-Grade Build: Cast bronze body construction and brass internal trim minimize corrosion and extend the service life of the valve assembly

designed for heavy-duty applications including furnaces

preventing nuisance lockouts caused by poor wiring harness connectivity

If your motor is overheating due to improper capacitance or a failing dielectric

and enthalpy control sequences

Lennox 25W78 Insert 318518-761 Industrial-Grade Build: Cast bronze bodyThe Lennox 25W78 NOx Insert is a critical combustion component engineered specifically for Lennox gas furnaces to reduce nitrogen oxide emissions. Designed for high efficiency heating systems, this OEM Lennox replacement part ensures that the burner assembly maintains optimal fuel to air ratios for a cleaner, more environmentally compliant burn. Constructed from heavy duty steel to withstand high temperature furnace environments, the 25W78 insert