Common indicators include a yellow or lift-off flame

often indicating "Pressure Switch Stuck Open" or "Pressure Switch Stuck Closed

or diagnostic LED codes indicating a communication error on the control board

Built with high-grade thermocouple alloys

As a secondary fan control

Lennox 18M65 Gas Valve 30067439-890 Common indicators include a yellowThe Lennox 18M65 is a high performance 1 2" 2 stage natural gas valve designed for precision fuel regulation in residential and light commercial furnaces. As an authentic OEM replacement part, it is functionally identical to the Lennox 18M6501 and serves as a direct substitute for the Honeywell VR8205Q 2746. This 24VAC valve is engineered to handle up to 150,000 BTUH, providing the staged firing rates necessary to maintain high efficiency standards in