Bunn TU3Q - Manual (Page 24)

Page 24
SERVICE (cont.)
10288 031604
Location:
Viewing the brewer from the front, the sweetener
solenoid is mounted on the left side of the solenoid
mounting bracket which is secured to the bottom base
housing.
Test Procedure:
1. Disconnect the brewer from the power source.
2. With a voltmeter, check the voltage across the
brown/white and white/violet wires on the sweet-
ener solenoid terminals when the OFF/SELECTOR
switch is in the “SWEET” position and the start
switch is momentarily placed in the lower posi-
tion. Connect the brewer to the power source.
After the approximate setting on the delay dial,
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, re-
main for the approximate setting on the dilution
dial, and then return to its previous indication.
3. Disconnect the brewer from the power supply.
If voltage is present as described, proceed to #4.
If voltage is not present as described, refer to the Wir-
ing Diagrams and check the wiring harness.
4. Remove both wires from the coil and check for
continuity across the coil terminals. If continuity
is present as described, reconnect the brown/white
and white/violet wires and proceed to #5.
If continuity is not present as described, replace the
solenoid valve.
SWEETENER SOLENOID VALVE (OPTIONAL)
FIG. 18 SWEETENER SOLENOID VALVE
P2844
5. Check the solenoid valve for coil action. Connect
the brewer to the power source, place the
OFF/SELECTOR switch in the “SWEET” position
and momentarily place the start switch in the lower
position and release. At the start of a brew cycle,
listen carefully in the vicinity of the solenoid valve
for a “clicking” sound as the coil magnet attracts
and at the end of the brew cycle when the plunger
is released.
6. Disconnect the brewer from the power source.
If the sound is heard as described and sweetener will
not pass through the solenoid valve, there may be a
blockage in the sweetener line before or after the so-
lenoid valve or, the solenoid valve may require inspec-
tion for wear, and removal of particles.
If the sound is not heard as described, replace the
solenoid valve.
Removal and Replacement:
1. Remove all wires from the solenoid valves.
2. Turn off the sweetener supply to the brewer.
3. Disconnect the water lines to and from the sole-
noid valves.
4. Remove the two #8-32 keps nuts holding the
mounting bracket to the trunk base.
5. Lift out the bracket.
6. Remove the two #10-32 slotted-head screws hold-
ing the solenoid valve to the mounting bracket.
7. Securely install the new solenoid valve to the
mounting bracket.
8. Attach the mounting bracket to the trunk base.
9. Securely fasten the sweetener and water lines to
and from the solenoid valves.
10. Refer to Fig. 19 when reconnecting the wires.
FIG.19 SOLENOID VALVE TERMINALS
P2843
SWEETENER
SOLENOID (OPTIONAL)
BRN/WHI to
Selector Switch
WHI/VIO to Brew Timer TL1
WHI/VIO to Brew Solenoid