Bunn DUAL - Control Thermostat Removal and Replacement

Page 21
!
CAUTIO
N
HO
T WATER
.
MINU
T
ES
B
UNN-O-
M
ATIC
P/N 2
620
- 120 VAC
.
MINUTES
BUNN-O-MATIC
P/N 2620- 120 VAC
START
ON / WA
RMER
SELECTOR
READY
R
E
ADY
ON / WARMER
START
1
1
⁄2
gal
1
ga
l
1⁄
2
ga
l
SE
L
E
C
T
O
R
1
1⁄2
gal
1
gal
1⁄2
gal
CAUTIO N:
WARM ERS AND
SURFA
C
E
S
A
RE
HOT
Location:
The level control board is located inside the front
of the brewer just left of center on the component
bracket
Test Procedure:
1. Disconnect the brewer from the power source.
2. Remove the violet wire from terminal 1 & pink wire
from terminal 4 of the circuit board.
3. With a voltmeter, check the voltage across terminals
2 & 3. 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, proceed to #5.
SERVICE (cont.)
LEVEL CONTROL BOARD AND LEVEL PROBE (Electro/
mechanical only)
If voltage is not present as described, refer to the Wiring
Diagrams and check brewer wiring harness.
5. Reconnect the violet wire to terminal 1.
6. Carefully connect a piece of insulated jumper wire
toterminal4.Keeptheotherendofthiswireaway
from any metal surface of the brewer.
7. With a voltmeter, check the voltage across terminals
1 & 3. 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 after a delay of approximately 1 sec-
ond.
b.) 200 to 240 volts ac for two wire 200 or 240 volt
models after a delay of approximately 1 second.
8. Touch the free end of jumper wire to the brewer
housing. The indication must be 0.
9. Move the jumper wire away from the brewer hous-
ing. The indication must again be:
a.) 120 volts ac for two wire 120 volt models, three
wire 120/208 volt models and three wire 120/240
volt models after a delay of approximately 1 sec-
ond.
b.) 200 to 240 volts ac for two wire 200 or 240 volt
models after a delay of approximately 1 second.
10. Disconnect the brewer from the power source and
remove the jumper wire from terminal 4.
If voltage is present as described, the level control
board is operating properly, proceed to #11.
If voltage is not present as described, replace the level
control board.
11. Reconnect the pink wire to terminal 4.
12. Gently pull the probe out of the tank lid and inspect
for corrosion. Replace it if necessary.
13. Place the probe so that neither end is in contact
with any metal surface of the brewer.
14. With a voltmeter, check the voltage across terminals
1 & 3. 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 after a delay of approximately 1 sec-
ond.
P796
FIG. 18 LIQUID LEVEL CONTROL BOARD
41976 031709