Bypass Valve - Bunn Dual Operating & Service Manual

SERVICE (cont.)

BYPASS VALVE

FIG. 1 BYPASS VALVES
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 a server beneath the funnel.
2. Check the water level in the tank to confirm that it
is within 1/2" from the top of the tank.
3. Connect the brewer to the power source.
4. Check the bypass valve for coil action. Place the
ON/OFF switch in the "ON" position, press and
release the BREW switch. Listen carefully in the
vicinity of the bypass valve for a "clicking" sound as
the coil magnet attracts and repels the plunger.
5. Disconnect the brewer from the power source.
If the sound is heard as described, there may be a
blockage in the bypass valve or the water line to the
sprayhead. Remove the bypass valve and inspect for
wear, and remove waterborne particles.
If the sound is not heard as described, proceed to #6.
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6. Connect the voltmeter lead ends to the bypass
valve coil terminals. Connect the brewer to the
power source. With the selector switch in the 1 or
1-1/2 gallon position, place "ON/OFF" Switch in the
"ON" position. Press and release the brew switch.
The indication must be:
a.) 120 volts ac for three wire 120/208 volt and
three wire 120/240 volt models.
b.) 200 to 240 volts ac for two wire 200 or 240 volt
models.
7. Disconnect the brewer from the power source.
If voltage is present as described, but no coil action is
observed, nor "clicking" heard, bypass valve is defec-
tive. Replace valve and test again to verify repair.
If voltage is not present as described, refer to Wiring
Diagrams and check the brewer wiring harness. Also
check the control board for proper operation. See
Pages 22 through 27.
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 Fig. 2 when reconnecting the wires.
LEFT AND RIGHT VALVE
FIG. 2 BYPASS VALVE TERMINALS
Page 15
WHI/GRN To Dispense Valve
WHI/VIO to Brew Selector
Switch
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