Control Thermostat - Bunn VP17 series Service & Repair Manual

SERVICE (cont.)

CONTROL THERMOSTAT

FIG. 2 CONTROL THERMOSTAT
Location:
The control thermostat is located inside the trunk
on the left side of the component bracket.
Test Procedures:
1. Disconnect the brewer from the power source.
2. With a voltmeter, check the voltage across the
blue wire on the control thermostat and the white
wire on the tank heater. Connect the brewer to the
power source. The indication must be:
a) 100 volts ac for two wire 100 volt models.
b) 120 volts ac for two wire 120 volt models.
3. Disconnect the brewer from the power source.
If voltage is present as described, proceed to #4.
If voltage is not present as described, refer to the Wiring
Diagrams and check the brewer wiring harness.
4. Gently remove the capillary bulb and grommet
from the tank.
5. With a voltmeter, check the voltage across the black
wire of the control thermostat and the white wire
on the tank heater when the control thermostat is
turned "ON" (Fully clockwise). Connect the brewer
to the power source. The indication must be:
a) 100 volts ac for two wire 100 volt models.
b) 120 volts ac for two wire 120 volt models.
6. Voltage must not be present when the thermostat
is turned to the "OFF" position.
7. 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.
Removal and Replacement:
1. Remove wires from control thermostat leads.
2. Remove the thermostat capillary bulb by firmly
pulling up on the capillary at the tank lid. This will
disengage the grommet from the tank lid.
3. Remove the one #8-32 screw securing the con-
trol thermostat to the component bracket in the
trunk.
4. Slide the grommet to the line 4.5" above the bulb
P1161.40
on the new capillary tube.
5. Insert the capillary bulb through the hole in the
tank lid and press the grommet firmly and evenly
so that the groove in the grommet fits into the tank
lid.
6. Carefully bend the capillary tube so that the tube
and bulb inside the tank are in the vertical posi-
tion.
NOTE - The capillary tube must be clear of any electri-
cal termination and not kinked.
7. Using one #8-32 screw secure the control thermo-
stat to the component bracket inside the trunk.
8. Refer to Fig. 3 when reconnecting the wires.
9. Adjust the control thermostat as required.
FIG. 3 CONTROL THERMOSTAT TERMINALS
Page 4
BLU to BLU Lead from
Limit Thermostat
BLK to BLK Lead from
Tank Heater
P1263
46721 052512