Bunn Ultra NX Service & Repair Manual page 39

SERVICE - REAR COVER COMPONENTS
Left and Right PTC Heater
FIG. 17 DEFROST HEATER/PTC
Part Removal and Replacement:
1. Disconnect the dispenser from the power
source.
2. Locate the auger motor 4-pin connector,
push-in the connector tab to release connector
from the machine wiring harness.
NOTE: When removing or installing the motor
be sure the split pin in the motor shaft is turned
to a position that will clear the torque sensor
circuit board.
3. Use a 7/16" nut driver or deep well socket to
remove the 3 nuts securing the auger motor
bracket to the chassis.
4. Grab the auger motor with mounting bracket
and begin pulling motor away from auger shaft
being careful that the motor .188 pin clears the
board sensor.
5. Pull insulating pipe cork tape away that is
covering the defrost heater and set aside.
6. Disconnect the defrost heater 3 pin connector
from the machine wiring harness.
7. Locate and grab the defrost heater spring clip,
pull on the spring clip to remove defrost heater
from drum housing. See FIG. 17 & 18.
NOTE: A little force may be needed to pull
defrost heater because the spring clip acts as
wedge to keep defrost heater firmly in position.
8. Before installation of replacement defrost heater,
ensure the heat sink compound is evenly
distributed over the defrost heater surface
that is going to be in direct contact with the
drum housing.
9. Facing the rear cooling drum, position the
surface with the heat sink compound on the
defrost heater assembly to the left and begin
pushing the heater all the way into the housing
until it stops.
10. Reconnect the defrost heater 3-pin connector to
the machine wiring harness.
11. Reuse or use new insulating pipe cork tape to
cover the defrost heater.
FIG. 18 DEFROST HEATER/PTC
39
Spring Clip