Repair· Easy 10 min
Fix intermittent flameout after 4–7 seconds of ignition.
Tools
1/4" nut driver · Fine Scotch-Brite pad · Multimeter (µA)
1
Kill power
Switch off furnace power and shut off gas.
2
Remove sensor
Single screw at burner assembly. Do not bend the rod.
3
Polish rod
Very light Scotch-Brite. Never sandpaper — leaves silica residue that insulates.
4
Verify µA
Series-connect meter on µA scale. Healthy 2–6 µA; replace below 0.5 µA.