I have an older (1988) Sears natural gas furnace. The furnace will turn on the exhaust fan and I can see and hear the igniter trying to light the burners. I have a Honeywell ignition gas control valve (vr8440p2088) I noticed it has a manual on/off knob that has broken off; it also has push and turn written on the knob. When I replace the broken knob on the control value, I can get the burners to light and normal operation of furnace resumes. The catch is I have to hold on the button down for gas to flow to the burners. Once I release the knob and let it go back up the burners shut off and it the igniter try’s to light it again.
What does that knob do when it’s pushed in?
Any help is appreciated.