Bunn TU3Q-EZ - Manual (Page 20)

Page 20
SERVICE (cont.)
TEMPERATURE PROBE
FIG. 12 TEMPERATURE PROBE
P1798.40
Location:
The temperature probe is located on the tank rear
of the tank lid, behind the tank heater.
Test Procedures:
1. Disconnect the brewer from the power source.
2. Remove the temperature probe from the grom-
met.
3. Submerge the probe in a water bath of approxi-
mately 70
°F (21°C).
4. Connect an ohmmeter to pins 2 and 3 of the J-5
connector on the control board. The indications
should be as follows:
a) 15.3k
± 2k OHMS at 60°F (15°C)
b) 11.8k
± 2k OHMS at 70°F (21°C)
c) 9.3k ± 2k OHMS at 80°F (27°C)
If resistance is present as described, the temperature
probe is operating properly.
If resistance is not present as described, replace the
temperature probe.
Removal and Replacement:
1. Disconnect the brewer from the power source.
2. Pull the existing probe from the tank lid.
3. Cut the white and black wires close to the probe
and discard the probe. Do not disconnect these
wires from the electronic control assembly.
4. On the new probe, cut the white and black wires
near the terminals. Discard the terminals. Insert
the new probe into the tank assembly.
5. Insert the white wire from the new probe and the
white wire from the electronic control assembly
into one of the UR connectors provided with the
replacement kit, and carefully crimp the connec-
tor.
6. Insert the black wire from the new probe and the
black wire from the electronic control assembly
into the remaining UR connector provided with
the replacement kit, and carefully crimp the con-
nector.
7. Refer to Fig. 13 when reconnecting the wires.
FIG. 13 TEMPERATURE PROBE TERMINALS
P2225
To Control Board J-5,
Pins 2 & 3
29460 082300