Control Thermostat - Bunn Single TF Operating & Service Manual

SERVICE (cont.)

CONTROL THERMOSTAT

22978.0000
J1
J2
SET
LOC
K
Location:
The control thermostat is located inside the
lower left front of the brewer on the component
bracket.
1. Disconnect the brewer from the power source.
2. Locate the blue wires on the control thermostat.
3. Check the voltage across the blue wires on the
control thermostat and the white insert on the two
or three pole 120V, 120/208V, 120/240V terminal
block and the red insert on two pole 200V or 240V
terminal blocks with a voltmeter. Connect the
brewer to the power source. The indication must
be:
a.) 120 volts ac for two wire 120 volt models, three
wire 120/208 volt models and three wire 120/240
volt models.
b.) 200 to 240 volts ac for two wire 200 or 240 volt
models.
4. Disconnect the brewer from the power source.
If voltage is present as described, reconnect the wire
and proceed to #5.
If voltage is not present as described, refer to the
wiring diagrams and check the brewer wiring harness
5. Locate the black wires on the control thermostat.
6. Gently remove the capillary bulb and grommet
from the tank.
7. Check the voltage across the black wires of the
control thermostat and the white insert on the two
pole or three pole 120V, 120/208V or 120/240V
terminal blocks and the red insert on two pole
200V/240V terminal blocks with a voltmeter when
the control thermostat is turned "ON" (fully clock-
wise). Connect the brewer to the power source.
The indication must be:
a.) 120 volts ac for two wire 120 volt models, three
wire 120/208 volt models and three wire 120/240
volt models.
b.) 200 to 240 volts ac for two wire 200 or 240 volt
models.
Voltage must not be indicated across these termi-
nals when the thermostat is turned "OFF" (fully
counterclockwise).
P999
8. Disconnect the brewer from the power source.
If voltage is present as described, reinstall the capil-
lary tube into the tank to the line 7" above the bulb, the
control thermostat is operating properly.
If voltage is not present as described, replace the
thermostat.
Page 20
27118 100400