Service and Parts | 6-7
Thermocouple Replacement
The tip of the thermocouple is positioned in the furnace so that it is
near, but not touching, the cell housing or the furnace heater coil.
Use Figure 8-3:
1. Open the sensor door to expose sensor components.
2. Disconnect thermocouple wires from terminals +TC- on the sensor
board.
3. Remove the 2 speed clips from the thermocouple mounting tabs. Use
needle-nose pliers to remove the clips.
4. Pull the thermocouple straight down and remove it from the furnace.
5. Insert the new thermocouple aligning the tab with the two posts on
the bottom plate. Be careful not to damage the ceramic tip while inserting
the assembly.
6. Attach one new speed nut to each post.
7. Attach the thermocouple wires to the +TC- terminals on the sensor
card (yellow wire is positive (+)).
8. Perform an oxygen calibration.