BICO Electric Funace - Manual (Page 6)

THERMOCOUPLE
REPLACEMENT
To replace the Thermocouple:
1. Unplug Furnace
2. Remove screened back from Furnace
3. Undo nuts that hold thermocouple to Pyrometer
4. Take OFF insulation from old thermocouple wires and put it on new thermocouple.
5. Remove old Thermocouple
6. Insert new Thermocouple into Furnace
7. Place lighted match near Thermocouple in Furnace and see if the needle goes up scale.
If the needle goes down scale when heat is applied, then reverse the leads to the Pyrometer.
8. Replace Furnace back
9. Plug in Furnace