Bypass Valve - Bunn Dual TF Operating & Service Manual

SERVICE (cont.)

BYPASS VALVE

1
5
6 .5 .5
A TI A TI C C 4
-M -M 7
N N N N -O -O 3
B U B U 4
5 8
3 2
2 2 6 1
1. 5 1. 5
1
1
3 A C A C
0 V 0 V
12 12
.5 .5
00 00
6- 00 6- 00
48 48
24 24
P /N P /N
Location:
The bypass valves are located inside the right
front and the center front of the hood.
Test Procedures:
1. Disconnect the brewer from the power source and
place 1-3/4 gallon server under funnel.
2. Disconnect the white/green wire and the white/
violet wire on the bypass valve.
NOTE: ECA MODELS ONLY - Brewer must be at
operating temperature to perform step #3 or brew-
lock must be bypassed. To bypass brew-lock
disconnect white/orange and brown/black for right
timer or orange and red/black for left timer from
brew-lock of ECA and connect harness leads to-
gether.
3. Check the voltage across the white/green and the
white/violet wires with a voltmeter. Connect the
brewer to the power source. With the "ON/OFF"
switch in the "ON' position, the selector switch in
the 1 or 1-3/4 gallon position press the start
switch. The indication must be:
a.) 120 volts ac for three wire 120/208 volt mod-
els 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, proceed to #5.
l
ga
1 1⁄2
1 ga l
l
ga
1⁄2
D Y
R EA
R
C TO
LE
SE
M ER
AR
/ W
O N
T
AR
ST
5
C C 6
A TI A TI 4
-M -M 7
-O -O
N N N N 3
B U B U 4
5 8
3 2
ga l
2 2 6 1 1 1⁄2
l
1. 5 1. 5 1 ga
l
1⁄2 ga
1
A C A C
3 0 V 0 V T
AR
12 12 ST
00 00
6- 00 6- 00
48 48 M ER
24 24 AR
P /N P /N / W
O N
R
C TO
LE
SE
D Y
R EA
If voltage is not present as described refer to the wiring
diagrams and check the brewer wiring harness.
5. Check for continuity across the bypass valve coil
terminals.
If continuity is present as described, reconnect the
white/green and white/ violet wires to the bypass
valve, brew-lock if necessary and proceed to #6.
If continuity is not present as described, replace the
bypass valve.
6. Check the bypass valve for coil action. Connect
brewer to the power source. With the "ON/OFF"
switch in the "ON" position press the start switch.
Listen carefully in the vicinity of the by-pass valve
for a "clicking" sound as the coil attracts and repels
the plunger.
If the sound is heard as described, there may be a
P971
blockage in the water line before the bypass valve or
the bypass valve may require inspection for wear and
removal of waterborne particles.
If the sound is not heard as described, replace the
bypass valve.
Removal and Replacement:
1. Remove the wires from the bypass valve.
2. Drain enough water from the tank so bypass valve
is above the water line.
3. Remove water lines from bypass valve.
4. Remove the two nuts retaining the bypass valve
inside the hood and remove bypass valve.
5. Remove hose barb fitting and attach to new by-
pass valve.
6. Install new bypass valve with hose barb fitting.
7. Reconnect the water tubes and the wires to the
bypass valve.
8. Refer to the illustration below when reconnecting
the wires.
Page 13
WHI/GRN to Dispense Valve
WHI/VIO to Brew Selector Switch
LEFT AND RIGHT VALVE
P774
27124 050800