Bypass Valve - Bunn Dual Service Manual

SERVICE (cont.)

BYPASS VALVE

FIG. 1 BYPASS VALVES
Location:
The bypass valves are located on the sprayhead
panel inside 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
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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 two wire 120 volt models,
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 defective.
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.
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 bypass
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.
NOTE: If one of the terminals is marked "I", connect
WHI/GRN wire to it.
FIG. 2 BYPASS VALVE TERMINALS
Page 11
WHI/GRN to Dispense
Valve
WHI/VIO to Brew
Selector Switch
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41976 031709