This equipment heats and dispenses water on demand for beverages and cooking purposes. It has a panel
above the faucet that indicates the status of the dispenser. This equipment is for indoor use, either wall-mounted
or on a sturdy counter or shelf.
WARRANTY
Bunn-O-Matic Corp. (“Bunn”) warrants the equipment manufactured by it to be commercially free from defects
in material and workmanship existing at the time of manufacture and appearing within one year from the date of
installation. In addition:
1.) Bunn warrants electronic circuit and/or control boards to be commercially free from defects in material and
workmanship for two years from the date of installation.
2.) Bunn warrants the compressor on refrigeration equipment to be commercially free from defects in material
and workmanship for two years from the date of installation.
3.) Bunn warrants that the grinding burrs on coffee grinding equipment will grind coffee to meet original factory
screen sieve analysis for three years from date of installation or for 30,000 pounds of coffee, whichever comes first.
This warranty does not apply to any equipment, component or part that was not manufactured by Bunn or that,
in Bunn’s judgement, has been affected by misuse, neglect, alteration, improper installation or operation, improper
maintenance or repair, damage or casualty.
THE FOREGOING WARRANTY IS EXCLUSIVE AND IS IN LIEU OF ANY OTHER WARRANTY, WRITTEN OR
ORAL, EXPRESS OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, ANY IMPLIED WARRANTY OF EITHER
MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. The agents, dealers or employees of Bunn are
not authorized to make modifications to this warranty or to make additional warranties that are binding on Bunn.
Accordingly, statements by such individuals, whether oral or written, do not constitute warranties and should not
be relied upon.
The Buyer shall give Bunn prompt notice of any claim to be made under this warranty by telephone at (217)
529-6601 or by writing to Post Office Box 3227, Springfield, Illinois, 62708-3227. If requested by Bunn, the Buyer
shall ship the defective equipment prepaid to an authorized Bunn service location. If Bunn determines, in its sole
discretion, that the equipment does not conform to the warranty, Bunn shall repair the equipment with no charge
for parts during the warranty period and no charge for labor by a Bunn Authorized Service Representative during
the warranty period. If Bunn determines that repair is not feasible, Bunn shall, at its sole option, replace the
equipment or refund the purchase price for the equipment.
THE BUYER’S REMEDY AGAINST BUNN FOR THE BREACH OF ANY OBLIGATION ARISING OUT OF THE SALE
OF THIS EQUIPMENT, WHETHER DERIVED FROM WARRANTY OR OTHERWISE, SHALL BE LIMITED, AS
SPECIFIED HEREIN, TO REPAIR OR, AT BUNN’S SOLE OPTION, REPLACEMENT OR REFUND.
In no event shall Bunn be liable for any other damage or loss, including, but not limited to, lost profits, lost sales,
loss of use of equipment, claims of Buyer’s customers, cost of capital, cost of down time, cost of substitute
equipment, facilities or services, or any other special, incidental or consequential damages.
2
10420 072500
Page 3
USER NOTICES
The notices on this dispenser should be kept in good condition. Replace unreadable or damaged labels.
12593.0000
00656.0000
00831.0000
3
10044.0000
10420 072500
Page 4
ELECTRICAL REQUIREMENTS
O
N
OFF
m
b
tric
O
C
M
A
G
CAUTION - The dispenser must be disconnected from the power source until specified in
Initial Set-Up.
This dispenser requires 2-wire, grounded service rated 120, 208, or 240 volts ac, 20 amp, single phase.
(Refer to the dispenser’s dataplate for exact voltage requirement.)
Electrical Hook-Up
CAUTION – Improper electrical installation will damage electronic components.
WHITE
NEUTRAL
L1 BLACK
120V.A.C.
1.An electrician must provide electrical service as specified.
2.Using a voltmeter, check the voltage and color coding of each conductor at
the electrical source.
3.Remove the upper and lower rear panels. Place the tank heater switch on the
electronic control assembly in the “OFF” position.
L2 RED
4.Install a strain relief and the proper electrical wiring to the terminal block.
5.Connect the dispenser to the power source and verify the voltage at the termi-
208 or 240V.A.C.
L1 BLACK
nal block before proceeding. Reinstall both rear panels.
6.If plumbing is to be hooked-up later be sure the dispenser is disconnected from
the power source. If Plumbing has been hooked-up, the dispenser is ready for
Initial Set-Up
.
PLUMBING REQUIREMENTS
This dispenser must be connected to a COLD WATER system with operating pressure between 20 and 90 psi (138
and 620 kPa) from a 1⁄2" or larger supply line. A shut-off valve should be installed in the line before the dispenser.
Install a regulator in the line when pressure is greater than 90 psi (620 kPa) to reduce it to 50 psi (345 kPa). The
water inlet fitting is 1⁄4" flare.
NOTE - Bunn-O-Matic recommends 1⁄4" copper tubing for installations of less than 25 feet and 3⁄8" for more than
25 feet from the 1⁄2" water supply line. At least 18 inches of an FDA approved flexible beverage tubing, such as
reinforced braided polyethylene or silicone, before the dispenser will facilitate movement to clean the countertop.
It can be purchased direct from Bunn-O-Matic (part number 00326-0000). Bunn-O-Matic does not recommend
the use of a saddle valve to install the dispenser. The size and shape of the hole made in the supply line by this type
of device may restrict water flow.
This equipment must be installed to comply with the Basic Plumbing Code of the Building Officials
and Code Administrators International, Inc. (BOCA) and the Food Service Sanitation Manual of the
1. Flush the water line and securely attach it to the flare fitting on the
rear of the dispenser.
2. Turn-on the water supply.
This equipment is to be installed to
comply with the Basic Plumbing Code of
Administrators International, Inc. (BOCA)
the Building Officials and Code
and the Food Service Sanitation M
of the Food and Drug Administration (FDA).
anual
P1770
4
10420 072500
Page 5
INITIAL SET-UP
OFF
CAUTION - The dispenser must be disconnected from the power source throughout the initial set-up, except
when specified in the instructions.
1.Remove the upper rear panel and place the tank heater switch in
the “OFF” position and replace the panel.
2.Connect the dispenser to the power source and turn-on the water
supply.
3.Water will automatically flow into the tank to the proper level and
shut-off. This will take approximately 10 minutes.
DO NOT
!
CAUTION
Until Water Comes From Opened Faucet!
Turn On The Tank Heater Switch
H
ot W
Automatically When Unit Is C
ater Systems –
Coffee Brew
Accordance W
ers –
Failure To Comply Voids Warranty!
ith The Installation Instructions!
W
ater Tank W
Fill The W
onnected To Power!
ater Tank In
ON
ill Fill
O
O
N
N
STOP
READ NOTICE
4.Disconnect the dispenser from the power source, remove the up-
per rear panel and place the tank heater switch in the “ON” position, and replace the panel.
WARNING
HAZARDOUS
VOLTAGE
DISCONNECT FROM
POWER SOURCE
BEFORE REMOVING!
5.Connect the dispenser to the power source and wait approximately
twenty minutes for the water in the tank to heat.
6.On models with ready indicator, the indicator will glow when the
P1771
proper water temperature for use is achieved.
NOTE - Discontinue dispensing if the indicator LED turns off. Dispense only when the indicator LED glows.
DRAINING THE DISPENSER
CAUTION - The dispenser must be disconnected from the power source throughout these steps.
1. Disconnect the dispenser from the power source.
2. Shut-off and disconnect the incoming water supply
3. Remove the 4-40 screws at the sides of the top panel.
4. Gently remove one of the grommets from the tank lid.
5. Insert a tube to the bottom of the tank and syphon ALL of the water out. Bunn-O-Matic has a syphon assem-
bly available (#12440.0000) for this purpose.
NOTE - The dispenser must be full using the INITIAL SET-UP steps before reconnecting to the power source.
CLEANING
The use of a damp cloth rinsed in any mild, non-abrasive, liquid detergent is recommended for cleaning all
surfaces on Bunn-O-Matic equipment.
WALL MOUNTED INSTALLATION
If the dispenser is wall mounted, the bottom of the dispenser should be at the same height as a counter or
table top. Use B.O.M. part #12542.0000 for side mounted Wall Bracket Kit or # 13125.0001 for front mounted
Wall Bracket Kit .
SUPPORT FOR LARGE RECEPTACLES
CAUTION: If the dispenser is to be used with larger receptacles such as pitchers or pots, those receptacles must
be adequately supported during dispensing of hot water to avoid spillage of very hot water. This support may be
provided by a table or counter top, or use B.O.M. part #12599.0000 Shelf Kit
5
10420 072500
Page 6
TROUBLESHOOTING
A troubleshooting guide is provided to suggest probable causes and remedies for the most likely problems
encountered. If the problem remains after exhausting the troubleshooting steps, contact the Bunn-O-Matic Technical Service Department.
•Inspection, testing, and repair of electrical equipment should be performed only by qualified service personnel.
•All electronic components have 120 – 240 volt ac and low voltage dc potential on their terminals. Shorting of
terminals or the application of external voltages may result in board failure.
•Intermittent operation of electronic circuit boards is unlikely. Board failure will normally be permanent. If an
intermittent condition is encountered, the cause will likely be a switch contact or a loose connection at a
terminal or crimp.
•Solenoid removal requires interrupting the water supply to the valve. Damage may result if solenoids are
energized for more than ten minutes without a supply of water.
•The use of two wrenches is recommended whenever plumbing fittings are tightened or loosened. This will
help to avoid twists and kinks in the tubing.
•Make certain that all plumbing connections are sealed and electrical connections tight and isolated.
•This dispenser is heated at all times. Keep away from combustibles.
WARNING
•Exercise extreme caution when servicing electrical equipment.
•Disconnect the dispenser from the power source when servicing, except when electrical tests are speci-
fied.
•Follow recommended service procedures
•Replace all protective shields or safety notices
Problem
Equipment will not operate.
Probable Cause
1. No power or incorrect voltage
2. Safety overflow switch
Remedy
(A) Check the terminal block for the correct voltage. It should be:
a.) 100 to 120 volts ac across the black and
white terminals for 100 to 120 volt models
or,
b.) 200 to 240 volts ac across the red and
black terminals for 200 to 240 volt models.
(B) Check circuit breakers or fuses.
Refer to Service – safety overflow switch
for testing procedures. See page 17.
6
10420 011599
Page 7
TROUBLESHOOTING (cont.)
ProblemProbable CauseRemedy
Automatic refill will not operate
after drawing hot water.
Water flows into the tank continuously (Dispenser disconnected from power source).
1. No water
2. Water strainer/flow control
3. Safety overflow switch
4. Liquid level system
5. Solenoid valve
1. Solenoid valve
Check plumbing and shut-off valves.
(A) Direction of flow arrow must be pointing towards dispenser.
(B) Remove the strainer/flow control and
check for obstructions. Clear or replace.
Refer to Service – safety overflow switch
for testing procedures. See page 17.
Refer to Service – electronic controls for
testing procedures. See page 10.
Refer to Service – solenoid valve for testing procedures. See page 18.
Refer to Service – solenoid valve for testing procedures. See page 18.
Water flows into the tank continuously (Dispenser connected
1. Liquid level system
Refer to Service – electronic controls for
testing procedures. See page 10.
to power source).
Water is cold.
1. Tank heater switch
Tank heater switch must be in the “ON”
position.
2. Safety overflow switch
Refer to Service – safety overflow switch
for testing procedures. See page 17.
3. Limit thermostat
Refer to Service – limit thermostat for testing procedures. See page 16.
CAUTION – Do not eliminate or bypass limit thermostat. Use only B.O.M. replacement part #23717.0001.
4. Tank heater
Refer to Service – tank heater for testing
procedures. See page 19.
5. Temperature control
Refer to Service – electronic controls for
testing procedures. See page 10.
7
10420 011599
Page 8
TROUBLESHOOTING (cont.)
ProblemProbable CauseRemedy
Water boils continuously.
1. Temperature control
Refer to Service – electronic controls for
testing procedures. See page 10.
2. Lime build-up
Inspect the tank assembliy for excess lime
deposits. Delime as required.
CAUTION – Tanks and tank components should be delimed reglarly depending on local water conditions. Excessive mineral build-up on stainless steel surfaces can initiate corrosive reactions resulting in serious leaks.
Dispenser is making unusual
noises.
1. Solenoid valve
2. Plumbing lines
The nut on top of the solenoid valve must
be tight or it will vibrate during operation.
Plumbing lines should not be resting on the
counter top.
3. Water supply
(A) The dispenser must be connected to a
cold water line.
(B) Water pressure to the dispenser must
not be higher than 90 psi (620 kPa). Install
a regulator if necessary to lower the working pressure to approximately 50 psi (345
kPa).
Ready indicator will not light.
(when temperature is within 4°
of its selected setting.)
1. Temperature control
2. Ready Indicator LED
Refer to Service – electronic controls for
testing procedures. See page 10.
Replace the indicator LED.
8
10420 072500
Page 9
SERVICE
OFF
OFF
O
FF
This section provides procedures for testing and
replacing various major components used in this dispenser should service become necessary. Refer to
Troubleshooting for assistance in determining the cause
of any problem.
Component Access
WARNING – Disconnect the dispenser from the power
source before the removal of any panel or the replacement of any component.
The limit thermostat, liquid level probe, tank heater,
and temperature sensor are located at the top of the
dispenser. Access is gained by removing the top lid,
attached with three 4-40 slotted-head screws.
The triac assembly is located beneath the tank. Access
is gained by removing four feet and the bottom panel
attached with seven 8-32 slotted-head screws.
NOTE - Completely drain the tank before tipping the
dispenser.
P1770
The check valve, electronic control assembly, safety
overflow switch, solenoid valve, overflow tube temperature sensor and terminal block are located at the
rear of the dispenser. Access is gained by removing
the upper and lower rear panels. The upper is attached
with six 8-32 slotted-head screws. The lower is attached
with four 8-32 slotted-head screws. The middle panel
must not be removed from the dispenser.
!
T
N
R
E
O
N
E
L
O
C
E
P
R
N
M
U
A
O
O
P
S
C
Y
Y
R
N
E
N
A
A
W
F
F
O
O
L
O
P
T
A
M
V
N
O
E
O
R
M
M
F
E
E
T
C
R
C
A
E
E
L
R
N
P
N
O
E
WARNING
F
R
O
E
C
!
B
S
I
D
DO NO
!
N
O
O
O
N
C
E
N
Until Wa
C
I
A
T
T
Turn O
O
U
N
STOP
T
D
ter Comes From
A
IO
E
n The Tank Heater Switch
Hot W
R
Au
N
tom
a
te
a
r S
tically W
y
C
stem
offe
Op
Acco
e B
h
s
e
–
ened F
n U
rdan
W
re
w
n
ate
F
it Is C
ers
ce
a
r Ta
i
W
– Fill Th
l
aucet!
u
ith Th
on
r
nk W
e
necte
T
o
ill Fill
e
e W
In
C
d To
o
stalla
a
m
te
Po
p
r Ta
l
tion
y
w
V
nk In
er
Instru
o
!
ids
ction
W
ar
s!
ra
nt
y!
P1770
WARNING – Inspection, testing, and repair of electrical
equipment should be performed only by qualified service personnel. Disconnect the dispenser from the
power source when servicing, except when electrical
tests are required and the test procedure specifically
states to connect the dispenser to the power source.
Tank Heater ........................................................ 19
Electronic Control Assembly Troubleshooting:
Check these items first
•Is circuit board popped-out of bracket?
•Is circuit board wet due to misaligned overflow
tube?
•Is water in overflow cup activating float switch?
•Is overflow cup not making good contact with tank?
•Is dispenser being operated with panels removed?
9
10420 011599
Page 10
SERVICE (cont.)
OFF
Electronic Controls
D
O NO
Un
til W
Hot Water Systems
Automatically When Unit Is Connected To Power!
Coffee Brewers
Accordance With The Installation Instructions!
F
a
!
T
Tu
a
ter
il
u
r
CAUTION
rn
O
Co
e
T
o
C
W
H
D
I
S
C
P
O
B
E
F
O
.0000
O
ON
O
N
E
N
C
P
I
T
O
O
T
S
N
D
A
E
n T
R
he Tank
mes From
H
Open
eater S
– Water Tank Will Fill
ed Fa
w
itch
– Fill The Water Tank I
uce
t!
o
m
p
ly
V
o
n
id
s
W
ar
r
a
n
t
y
!
A
R
N
I
N
G
A
Z
A
R
V
D
O
O
L
T
U
A
S
G
E
O
N
N
W
E
C
E
R
T
S
F
R
R
O
E
O
U
R
M
R
E
C
M
E
O
V
I
N
G
!
12561.0000
M2522.1000
00971.0000
P1773
Location:
FIG. 1 ELECTRONIC CONTROL
P1772
12565.0002
01520.0000
02328.0003
FIG. 2 TRIAC
The electronic control assembly is located inside the rear of the dispenser. Access will also be needed to the
temperature sensor, overflow tube temperature sensor, and liquid level probe located on the tank lid and to the
triac assembly located beneath the tank.
General:
This system controls the liquid level and water temperature of the dispenser. These two functions act independently of each other and should be tested separately.
H5E, H5X LIQUID LEVEL CONTROL
PROBLEM: Overflows
Drain cup
Unplug Ready Lamp
Retry
Liquid Level Control Flow Charts
No
No
Replace Ready Lamp
Replace Probe
H5E, H5X LIQUID LEVEL CONTROL
PROBLEM: Does Not Refill
Overflow Cup Full
?
No
Disconnect Level Probe
Voltage present at
Solenoid Valve
?
Unplug Ready Lamp
Ye s
Remove Power
Ye s
Does Water Flow
No
Replace Solenoid Valve
Drain cup
Retry
Overflow
?
Ye s
Drain cup
Disconnect Probe
Wire From Probe
Short Probe Wire
To Chassis
Retry
Overflow
?
Ye s
?
Ye s
No
Replace Probe
Drain cup
Disconnect Wire From
Solenoid Valve
Retry
Voltage present at
Solenoid Valve
?
No
Replace Control Assembly
Ye s
Replace Ready Lamp
10
Overflow
?
No
Replace Control Assembly
Ye s
Replace Solenoid Valve
10420 011599
Page 11
SERVICE (cont.)
Electronic Controls (cont.)
Liquid Level Control Test Procedure
1. Disconnect the dispenser from the power source.
2. Check the voltage across terminals 3 & 4 of the
electronic control assembly with a voltmeter. Connect the dispenser to the power source. The indication must be:
a.) 100 to 120 volts ac for 100 to 120 volt models
or
b.) 200 to 240 volts ac for 200 to 240 volt models.
3. Disconnect the dispenser from the power source.
If voltage was present as described, proceed to #4.
If voltage was not present as described, refer to
the Wiring Diagrams and check the dispenser wiring harness.
4. Remove the pink wire from terminal 5 of the elec-
Temperature Control Flow Charts
tronic control assembly.
5. Check the voltage across terminals 1 & 4 of the
electronic control assembly with a voltmeter. Connect the dispenser to the power source. The indication must be:
a.) 100 to 120 volts ac for 100 to 120 voltmodels
or
b.) 200 to 240 volts ac for 200 to 240 volt models
after a delay of approximately 5 seconds.
6. Disconnect the dispenser from the power source.
If voltage was present as described, the liquid level
control of the system is operating properly, proceed to
#7.
If voltage was not present as described, replace the
electronic control assembly and the temperature sensor in the tank lid.
NOTE - Each electronic control assembly is calibrated
to a temperature sensor. Both components MUST be
replaced as a set.
H5X THERMOSTAT
PROBLEM: Water Not Hot Enough
Jumper JP1
In Boil Position
?
Ye s
Red Light On
Constantly
?
Ye s
Measure Voltage
At Tank Heater
Voltage Present
?
No
Limit Thermostat OK
?
Ye s
Replace Control Assembly
Measure Voltage
At Tank Heater
Voltage Present
?
Ye s
Recheck Water Temperature
No
No
Replace Steam Sensor
Ye s
Replace Tank Heater
No
Replace Limit Thermostat
No
Check For Split Tank Heater
Reposition Jumper
Replace Triac
Reinstall Original
Control Assembly
Red Light On
Constantly
?
No
Replace Control Assembly
Ye s
Recheck Water Temperature
H5E THERMOSTAT
PROBLEM: Water Not Hot Enough
Red Light On
Constantly
?
Ye s
Measure Voltage
At Tank Heater
Voltage Present
?
No
Limit Thermostat OK
?
Ye s
Replace Control Assembly
Measure Voltage
At Tank Heater
Voltage Present
?
Ye s
Recheck Water Temperature
No
Clockwise Contiuously
Ye s
Replace Tank Heater
No
Replace Limit Thermostat
No
Check For Split Tank Heater
Turn Temperature
Adjustment Screw
Replace Triac
Reinstall Original
Control Assembly
Red Light On
?
No
Replace Control Assembly
Ye s
Adjust For Correct
Water Temperature
11
10420 011599
Page 12
SERVICE (cont.)
Electronic Controls (cont.)
7. Reconnect the pink wire to terminal 5 of the electronic control assembly.
8. Loosen the compression fitting, remove the probe
from the tank lid, and inspect it for mineral deposits. Replace it if necessary. Keep the exposed ends
of the probe away from any metal surface of the
dispenser.
9. Check the voltage across terminals 1 & 4 of the
electronic control assembly with a voltmeter. Connect the dispenser to the power source. The indication must be:
a.) 100 to 120 volts ac for 100 to 120 volt models
or
b.) 200 to 240 volts ac for 200 to 240 volt models
after a delay of approximately 5 seconds.
10. Touch the screw head end of the probe to the dispenser housing. The indication must be 0.
11. Move the probe away from the dispenser housing.
The indication must again be:
a.) 100 to 120 volts ac for 100 to 120 volt models
or
b.) 200 to 240 volts ac for 200 to 240 volt models
after a delay of approximately 5 seconds.
12. Disconnect the dispenser from the power source.
If voltage was present as described, reinstall the probe,
the sensing function of the system is operating properly.
If voltage was not present as described, check the pink
probe wire and the green ground wire for continuity
and/or replace the probe.
Temperature Control Test Procedure
1. Disconnect the dispenser from the power source.
2. Check the voltage across terminals 3 & 4 of the
electronic control circuit board with a voltmeter.
Connect the dispenser to the power source.The indication must be:
a.) 100 to 120 volts ac for 100 to 120 volt models
or
b.) 200 to 240 volts ac for 200 to 240 volt models.
3. Disconnect the dispenser from the power source.
If voltage was present as described, proceed to #4.
If voltage was not present as described, refer to the
Wiring Diagram and check the dispenser wiring harness.
4. Connect the dispenser to the power source and
place the tank heater switch in the “ON” position.
5. Observe the red indicator on the electronic control
circuit board.
6. Disconnect the dispenser from the power source.
Temperature Control Flow Charts (cont.)
H5X THERMOSTAT
PROBLEM: Boils Excessively - Fills Cup
Drain cup
Retry
Red Light On While
Boiling
?
Disconnect Blue Wire From
Control Board Pin 7
Retry
Still Boiling
?
No
Replace Control Assembly
Ye s
Replace Steam Sensor
No
Ye s
Replace Control Assembly
Ye s
Still Boiling
?
No
Finished
Replace Triac Assembly
Check For Split
Tank Heater
12
H5E THERMOSTAT
PROBLEM: Boils
Drain cup
Retry
Red Light On While
Boiling
?
No
Disconnect Blue Wire From
Control Board Pin 7
Retry
Still Boiling
?
No
Replace Control Assembly
Ye s
Replace Control Assembly
Ye s
Replace Triac Assembly
Check For Split
Tank Heater
10420 011599
Page 13
SERVICE (cont.)
Electronic Controls (cont.)
If the indicator was on or blinking, the temperature sensor is operating properly, proceed to #7.
If the indicator was off, check the sensor connection
on the electronic control circuit board and/or replace
the temperature sensor and the electronic control assembly.
NOTE - Each temperature sensor is calibrated to an
electronic control assembly. Both components MUST
be replaced as a set.
7. Check the voltage across the tank heater terminals
with a voltmeter. Connect the dispenser to the
power source. The indication must be:
a.) 100 to 120 volts ac for 100 to 120 volt models
or
b.) 200 to 240 volts ac for 200 to 240 volt models
while the red indicator on the circuit board is on or
blinking.
8. Disconnect the dispenser from the power source.
If voltage was present as described, the temperature
control of the system is operating properly.
If voltage was not present as described, contact BunnO-Matic to order an electronic control assembly, temperature sensor, and triac assembly for evaluation and
proceed to #9.
to a temperature sensor. Both components MUST be
replaced as a set.
10. Check the voltage across the tank heater terminals
with a voltmeter. Connect the dispenser to the
power source. The indication must be:
a.) 100 to 120 volts ac for 100 to 120 volt models
or
b.) 200 to 240 volts ac for 200 to 240 volt models
while the red indicator on the circuit board is on or
blinking.
11. Disconnect the dispenser from the power source.
If voltage was present as described, return the new
triac assembly to Bunn-O-Matic for credit. The temperature control of the system is operating properly.
If voltage was not present as described, reinstall your
existing electronic control assembly and temperature
sensor, and proceed to #12.
12. Replace the triac assembly.
13. Check the voltage across the tank heater terminals
with a voltmeter. Connect the dispenser to the
power source. The indication must be:
a.) 100 to 120 volts ac for 100 to 120 volt models
or
b.) 200 to 240 volts ac for 200 to 240 volt models
while the red indicator on the circuit board is on or
blinking.
14. Disconnect the dispenser from the power source.
9. Replace the electronic control assembly and temperature sensor.
NOTE - Each electronic control assembly is calibrated
If voltage was present as described, the temperature
control of the system is operating properly. Return the
new electronic control assembly and temperature sensor to Bunn-O-Matic for credit.
13
10420 011599
Page 14
SERVICE (cont.)
Electronic Controls (cont.)
Electronic Controls Removal and Replacement
NOTE - Each electronic control assembly is calibrated
to a temperature sensor probe. Both components MUST
be replaced as a set.
1. Remove all wires from the electronic control assembly terminals.
2. Remove the two 8-32 screws holding the electronic
control assembly to the component bracket.
3. Disconnect the temperature sensor, overflow tube
temperature sensor, and indicator wires from the
left side of the electronic control assembly board.
4. Remove the temperature sensor from the grommet in the tank lid.
5. Install the new temperature sensor into the grommet on the tank lid. Route the wires to the location
of the new electronic control assembly.
6. Attach the temperature sensor, overflow tube temperature sensor, and indicator wires to the electronic control assembly.
7. Fasten the new electronic control assembly to its
bracket.
BLU to Triac Assy
WHI/BRN to Tank Heater Switch
TAN to Triac Assy
PNK to Liquid Level Probe
WHI or RED to Terminal Block
BLK to Overflow Safety Switch
GRN to Chassis Ground
WHI/BLU to Solenoid
P1774
FIG. 3 WIRING CONNECTIONS
WHI & WHI to
Temperature Sensor
PNK & GRY to
Heater Indicator
Refill Indicator
Power Indicator
Ready Indicator
8. Reconnect the wires.
9. Review the initial set-up procedures.
Triac Assembly Removal and Replacement
NOTE - Each triac installation requires the use of an
approved silicone heat sink compound. Bunn-O-Matic
recommends the use of Dow Corning 340 compound or
equivalent. It can be purchased direct from Bunn-OMatic (part # 12572.0002).
1. Place the tank heater switch on the electronic control assembly in the “OFF” position.
2. Completely drain the tank.
3. Carefully set the dispenser on its face (faucet side).
4. Remove the four feet attached with four 8-32
phillips-head screws.
5. Remove the bottom panel and four feet attached
with seven 8-32 slotted-head screws.
6. Remove the existing triac assembly held in place
with a 10-32 hex keps nut.
7. Apply a small amount of the silicone heat sink compound to the copper heat sink.
8. Securely fasten the new triac assembly to the bottom of the tank in the same relative position as the
one removed. Bunn-O-Matic recommends tightening the nut to a torque setting of approximately 18
inch-pounds.
9. Route the wires up around the rear of the dispenser.
10. Reinstall the bottom panel and four feet.
11. Stand the dispenser upright.
12. Disconnect the other ends of the old triac assembly wires.
13. Connect the TAN and BLU wires with spade terminals of the new assembly to the electronic control
assembly, FIG. 3.
14. Connect the BLU wire with the ring terminal to the
tank heater, FIG. 13.
15. Connect the WHI/VIO wire of the new assembly to
the WHI or RED terminal at the terminal block.
GRY & GRY
toThermistor
FIG. 4 WIRING CONNECTIONS
P1774
14
10420 011599
Page 15
SERVICE (cont.)
85-115°110-140°135-165°160-190°185-208°
Electronic Controls (cont.)
Adjustments
This dispenser can maintain any temperature between
85 and 208°F by selecting and setting one of five variable range control potentiometers.
1. Fill the dispenser according to the steps in the Initial Set-up.
2. Select the range containing the desired temperature by plugging the two-pin socket onto the mating connector of one of the range control boards.
Both pins must be connected to the socket.
3. Place the tank heater switch in the “ON” position
and observe the glowing red indicator near the right
edge of the control board. The controller is applying full power to the heater when the indicator is
on all the time. The indicator will begin to flash as
the temperature nears the set point. The set temperature is reached when the indicator flashes only
very briefly. The water is hotter than the set temperature when the indicator remains off. This initial setting will only be an approximation.
4. Take the temperature of the stream of water immediately below the faucet as it flows from the dispenser with an accurate thermometer. Do not take
the temperature of water collected in a container.
5A. TO INCREASE THE TEMPERATURE
Turn the potentiometer screw of the temperature
range selected in step 2 in a clockwise direction
with a small screwdriver. One full turn of the screw
will result in an approximate 1°F change. Allow
the temperature to stabilize as described in step 3
and repeat step 4. Continue until the desired water
temperature is achieved.
5B. TO DECREASE THE TEMPERATURE
Turn the potentiometer screw of the temperature
range selected in step 2 in a counterclockwise direction with a small screwdriver. One full turn of
the screw will result in an approximate 1°F change.
Draw a large quantity of water at the faucet, allow
the temperature to stabilize as described in step 3
and repeat step 4. Continue until the desired water
temperature is achieved.
NOTE - The entire adjustment span is approximately
25 complete revolutions. The potentiometer will cease
to adjust when turned too far in either direction. It is
not damaged, simply turn it back a few turns and try
again.
FIG. 5 TEMPERATURE RANGE SELECTION
15
P1775
10420 011599
Page 16
SERVICE (cont.)
Limit Thermostat
Location:
The limit thermostat is located on the tank lid.
To test the limit thermostat, access will also be needed
to the terminal block located at the rear of the dispenser.
P1772
FIG. 6 LIMIT THERMOSTAT
Test Procedure:
1. Disconnect the dispenser from the power source.
2. There are two black wires on the limit thermostat
terminals. One comes from the terminal block. The
other goes directly to the tank heater terminal.
Remove the black wire at the limit thermostat coming from the terminal block.
3. Check the voltage across the black wire removed
from the limit thermostat and the white wire or red
wire of the terminal block with a voltmeter. Connect the dispenser to the power source. The indication must be:
a.) 100 to 120 volts ac for 100 to 120 volt models
or
b.) 200 to 240 volts ac for 200 to 240 volt models.
4. Disconnect the dispenser from the power source.
If voltage was present as described, reconnect the black
wire and proceed to #5.
If voltage was not present as described, refer to the
Wiring Diagrams and check the dispenser wiring harness.
5. Check for continuity across the terminals of the
limit thermostat.
If continuity is not present as described, the circuit is
broken. Press the reset button of the limit thermostat
and recheck for continuity.
If continuity is not present as described, replace the
limit thermostat.
Removal and Replacement:
1. Remove both wires from the limit thermostat terminals.
2. Remove the two #10-32 nuts attaching the limit
thermostat to the top of the tank.
3. Install the new limit thermostat and secure into
place with two #10-32 nuts.
4. Refer to FIG. 7 when reconnecting the wires.
BLK to Terminal Block
BLK to Tank Heater
Reset
P1776
FIG. 7 LIMIT THERMOSTAT WIRING
16
10420 011599
Page 17
SERVICE (cont.)
OFF
Safety Overflow Switch
DO NOT
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Until Water Comes From Opened Faucet!
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P1772
FIG. 8 SAFETY OVERFLOW SWITCH
Location:
The safety overflow switch is located inside the rear of
the dispenser inside the copper overflow cup.
For testing or removal of the safety overflow switch,
access may also be needed by removing the two screws
attaching the electronic control assembly to its mounting bracket.
Removal and Replacement:
1. Disconnect the black wires from the safety overflow switch.
2. Remove the nut beneath the copper overflow cup.
3. Remove the entire switch assembly from the cup.
4. Place the new switch assembly into the cup, wires
first. Make sure that a gasket is in place around the
threaded switch stem.
NOTE - The magnets must be at the top of the float and
there must be NO stainless steel washers installed for
the safety overflow switch to operate properly.
5. Install the nut beneath the copper overflow cup.
Be sure not to overtighten.
6. Reconnect the wires, FIG. 9.
Test Procedure:
1.Once voltage is verified at the power source, check
for continuity across the safety overflow switch
red wires only until the plastic float is raised and
check that continuity returns when the plastic float
is again lowered.
If continuity is present as described, reconnect each
of the red wires to the black wires, the safety overflow
switch is operating properly.
If continuity is not present as described, replace the
safety overflow switch.
RED to BLK Wire from
Terminal Block
RED to BLK Wire from
Electronic Control #3
P1777
FIG. 9 SAFETY OVERFLOW WIRING
17
10420 011599
Page 18
SERVICE (cont.)
Solenoid Valve
Location:
The solenoid valve is located inside the rear of the dispenser on the right side near the bottom.
To test the solenoid valve, access will also be needed
to the electronic control assembly.
1.Disconnect the dispenser from the power source
and turn-off the water supply to the dispenser.
2.Remove the pink wire from terminal 5 of the electronic control assembly.
3.Check the voltage across the solenoid valve coil
terminals with a voltmeter. Connect the dispenser
to the power source. The indication must be:
a.) 100 to 120 volts ac for 100 to 120 volt models
or
b.) 200 to 240 volts ac for 200 to 240 volt models
after a delay of approximately 5 seconds.
4.Disconnect the dispenser from the power source.
If voltage was present as described, proceed to #5.
If voltage was not present as described, refer to the
Wiring Diagrams and check the dispenser wiring harness.
7. Check the solenoid valve for coil action. Connect
the dispenser to the power source. Listen carefully
in the vicinity of the solenoid valve for a “clicking”
sound after approximately 5 seconds, as the coil
magnet attracts the plunger.
8. Disconnect the dispenser from the power source.
9. Reconnect the pink wire to terminal 5 of the electronic control assembly.
If the sound was heard as described and water will not
pass through the solenoid valve, there may be a blockage in the water line before or after the solenoid valve
or the solenoid valve may require inspection for wear
and removal of waterborne particles.
If the sound was not heard as described, replace the
solenoid valve.
Removal and Replacement:
1. Remove all wires from the solenoid valve coil.
2. Turn-off the water supply to the dispenser.
3. Disconnect the water lines to and from the solenoid valve.
4. Remove the two 8-32 slotted-head screws holding
the solenoid valve and mounting bracket to the
component bracket.
5. Lift-out the solenoid valve.
6. Remove the two 10-32 slotted-head screws holding the solenoid valve to its mounting bracket.
7. Securely install the new solenoid valve to its mounting bracket. The direction of flow arrow must be
pointing towards the tank lid.
8. Attach the solenoid valve and mounting bracket to
the component bracket.
9. Securely fasten the water lines to and from the solenoid valve.
10. Reconnect the wires, FIG. 11.
WHI/BLU to Electronic Control #1
5.Remove both wires from the solenoid valve coil
terminals.
6.Check for continuity across the solenoid valve coil
terminals.
If continuity is present as described, reconnect the
wires and proceed to #7.
If continuity is not present as described, replace the
solenoid valve coil.
18
WHI or RED to Terminal Block
P1779
FIG. 11 SOLENOID VALVE WIRING
10420 011599
Page 19
SERVICE (cont.)
N
e
m
T
e
OFF
Tank Heater
Location:
The tank heater is located in the tank lid.
Removal and Replacement:
1. Remove the wires to the tank heater.
2. Remove the 8-32 nuts from the tank heater flange.
3. Remove the tank heater.
4. Inspect the tank heater gasket and replace if necessary.
5. Securely install the new tank heater. Be certain of a
watertight seal.
6. Reconnect the wires, FIG. 13.
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P1772
FIG. 12 TANK HEATER
Test Procedure:
1. Disconnect the dispenser from the power source.
2. Check the voltage across the terminals of the tank
heater with a voltmeter. Connect the dispenser to
the power source. The indication must be:
a.) 100 to 120 volts ac for 100 to 120 volt models
or
b.) 200 to 240 volts ac for 200 to 240 volt models.
3. Disconnect the dispenser from the power source.
If voltage is present as described, proceed to #4.
If voltage is not present as described, replace the tank
heater.
4. Remove the tank heater from the tank lid and inspect it for cracks in the sheath.
If the sheath shows no sign of damage, proceed to #5.
If the sheath is damaged, replace the tank heater.
BLU to Triac Assy
FIG. 13 TANK HEATER WIRING
BLK to Limit
Thermostat
P1780
5. Check for continuity across the tank heater terminals.
If continuity is present as described, reinstall the tank
heater. The tank heater is operating properly.
If continuity is not present as described, replace the
tank heater.