Maintenance and Troubleshooting   |   5-43
OPTIONAL 
If working on the Heater Plate with it still in the Oven is not practi-
cal, remove it from the Oven. To do this, record all wire termination 
points at the Terminal Strips (J1, J2) inside the Seal Body and then 
disconnect the wires.  
 
Unscrew the Thermal Insulating Tube from the Lower Heater Plate, 
and move the tube downward to free it from the Heater Plate. 
 
Rotate the Seal Body/Thermal Insulation Tube away from the ana-
lyzer to allow more room to remove the Heater Plate, taking care not 
to damage the wires. 
 
Tilt the top of the Heater Plate forward and pull the Heater Plate up 
and out of the Oven. Move the Heater Plate to a suitable work bench 
to work on it.
11.  Replace the Heater Elements and RTDs (Figures 5-8 and 5-9):
Replacing a faulty Heater Element:
a.  Remove the faulty Heater Element from its channel in the Upper 
Heater Plate and carefully pull its wire out from the Seal Body and 
through the Lower Heater Plate.
b.  Install a new Heater Element (P/N 300-8684) in the channel it was 
removed from.
c.  Label the Heater Element wire “Overtemp Heater” or “Heater” as 
required.
Replacing internal Overtemp and/or Heater RTDs:
Looking at the front of the Heater Plate, the RTD on the right side is 
“Overtemp” and the RTD on the left side is “Heater”.
a.  Unscrew the faulty RTD from the Upper Heater Plate and care-
fully pull its wire out from the Seal Body and through the Lower 
Heater Plate.
b.  Thread the new RTD (P/N 300-4924) into the Upper Heater Plate 
and tighten it using short needle-nose pliers.
  Label the RTD wire “Overtemp RTD” or “Heater RTD” as required.
c.  Repeat Steps ‘a’ and ‘b’ if replacing the other RTD.
NOTE
NOTE