Bunn TB3 Guía Del Usuario
Page 17
SERVICE (cont.)
CONTROL THERMOSTAT
4
2
3
1
MI
NU
TE
S
M
IN
UT
ES
MI
NU
TE
S
M
IN
UT
ES
DE
LA
Y
D
IL
UT
IO
N
DE
LA
Y
D
IL
UT
IO
N
BU
NN
-O-
M
AT
IC
BU
NN
-O
-M
AT
IC
P/
N
33
55
P/
N
33
55
5
3
6
4
7
5
6
6
7
8
FIG. 4 CONTROL THERMOSTAT
P3040
Location:
The control thermostat is located inside hood on
the right side just behind the dilution timer.
Test Procedures:
1. Disconnect the brewer from the power source.
2. Locate the blue/black wire on the control thermo-
1. Disconnect the brewer from the power source.
2. Locate the blue/black wire on the control thermo-
stat.
3. With a voltmeter, check the voltage across the
blue/black wire on the control thermostat and
the white wire on the tank heater for 100 volt and
120 volt two wire models or red wire on the tank
heater for 230 volt two wire models. Connect the
brewer to the power source. The indication must
be:
the white wire on the tank heater for 100 volt and
120 volt two wire models or red wire on the tank
heater for 230 volt two wire models. Connect the
brewer to the power source. The indication must
be:
a) 120 volts ac for two wire 120 volt models.
b) 230 volts ac for two wire 230 volt models.
c) 100 volts ac for two wire 100 volt models.
4. Disconnect the brewer from the power source.
If voltage is present as described, proceed to #5.
If voltage is not present as described, refer to the Wir-
ing Diagrams and check the brewer wiring harness.
If voltage is not present as described, refer to the Wir-
ing Diagrams and check the brewer wiring harness.
5. Locate the black wire on the control thermostat.
6. Gently remove the capillary bulb and grommet
6. Gently remove the capillary bulb and grommet
from the tank.
7. With a voltmeter, check the voltage across the
black wire of the control thermostat and the white
wire on the tank heater for 100 volt and 120 volt
two wire models or red wire on the tank heater
for 230 volt two wire models when the control
wire on the tank heater for 100 volt and 120 volt
two wire models or red wire on the tank heater
for 230 volt two wire models when the control
thermostat is turned fully clockwise. Connect the
brewer to the power source. The indication must
be:
brewer to the power source. The indication must
be:
a) 120 volts ac for two wire 120 volt models.
b) 230 volts ac for two wire 230 volt models.
c) 100 volts ac for two wire 100 volt models.
8. Disconnect the brewer from the power source.
If voltage is present as described, reinstall the capillary
tube into the tank to the line 4.5" above the bulb, the
control thermostat is operating properly.
If voltage is not present as described, replace the
thermostat.
tube into the tank to the line 4.5" above the bulb, the
control thermostat is operating properly.
If voltage is not present as described, replace the
thermostat.
Removal and Replacement:
1. Remove both wires from the control thermostat
1. Remove both wires from the control thermostat
terminals.
2. Remove the thermostat capillary bulb by fi rmly
pulling up on the capillary tube at the tank lid. This
will disengage the grommet from the tank lid.
will disengage the grommet from the tank lid.
3. Remove the #8-32 screw holding the control
thermostat to its bracket.
4. Slide the grommet to the line 4.5" above the bulb
on the new capillary tube.
5. Insert the capillary bulb through the hole in the
tank lid and press the grommet fi rmly and evenly
so that the groove in the grommet fi ts into the tank
lid.
so that the groove in the grommet fi ts into the tank
lid.
6. Carefully bend the capillary tube so that the tube
and bulb inside the tank are in a vertical posi-
tion.
tion.
NOTE – The capillary tube must be clear of any electri-
cal termination and not kinked.
cal termination and not kinked.
7. Fasten the new control thermostat to its bracket.
8. Refer to Fig. 5 when reconnecting the wires.
9. Adjust the control thermostat as required.
8. Refer to Fig. 5 when reconnecting the wires.
9. Adjust the control thermostat as required.
FIG. 5 CONTROL THERMOSTAT TERMINALS
P1280
BLK to Tank
Heater
Heater
BLU/BLK to Limit Ther-
mostat
mostat
37235 080204