Bunn U3A Manuel de service
U3/SRU
SERVICE MANUAL
BUNN-O-MATIC CORPORATION
POST OFFICE BOX 3227
SPRINGFIELD, ILLINOIS 62708-3227
PHONE: (217) 529-6601 FAX: (217) 529-6644
To ensure you have the latest revision of the Operating Manual, or to view the Illustrated
Parts Catalog, Programming Manual, or Service Manual, please visit the Bunn-O-Matic
website, at www.bunn.com. This is absolutely FREE, and the quickest way to obtain the
latest catalog and manual updates. For Technical Service, contact Bunn-O-Matic Corporation
at 1-800-286-6070.
42770.0000C 07/16 ©2010 Bunn-O-Matic Corporation
BUNN-O-MATIC COMMERCIAL PRODUCT WARRANTY
Bunn-O-Matic Corp. (“BUNN”) warrants equipment manufactured by it as follows:
1) Airpots, thermal carafes, decanters, GPR servers, iced tea/coffee dispensers, MCR/MCP/MCA single cup brewers, thermal servers and ThermoFresh® servers (mechanical and digital) 1 year parts and 1 year labor.
2) All other equipment - 2 years parts and 1 year labor plus added warranties as specified below:
a) Electronic circuit and/or control boards - parts and labor for 3 years.
b) Compressors on refrigeration equipment - 5 years parts and 1 year labor.
c) Grinding burrs on coffee grinding equipment to grind coffee to meet original factory screen sieve analysis - parts and
labor for 4 years or 40,000 pounds of coffee, whichever comes first.
These warranty periods run from the date of installation BUNN warrants that the equipment manufactured by it will be
commercially free of defects in material and workmanship existing at the time of manufacture and appearing within the
applicable warranty period. This warranty does not apply to any equipment, component or part that was not manufactured
by BUNN or that, in BUNN’s judgment, has been affected by misuse, neglect, alteration, improper installation or operation,
improper maintenance or repair, non periodic cleaning and descaling, equipment failures related to poor water quality,
damage or casualty. In addition, the warranty does not apply to replacement of items subject to normal use including but
not limited to user replaceable parts such as seals and gaskets. This warranty is conditioned on the Buyer 1) giving 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; 2) if requested by BUNN, shipping the defective equipment prepaid to an authorized
BUNN service location; and 3) receiving prior authorization from BUNN that the defective equipment is under warranty.
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.
If BUNN determines in its sole discretion that the equipment does not conform to the warranty, BUNN, at its exclusive option while the equipment is under warranty, shall either 1) provide at no charge replacement parts and/or labor (during the
applicable parts and labor warranty periods specified above) to repair the defective components, provided that this repair
is done by a BUNN Authorized Service Representative; or 2) shall 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, AT BUNN’S SOLE OPTION
AS SPECIFIED HEREIN, TO REPAIR, 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.
392, A Partner You Can Count On, Air Infusion, AutoPOD, AXIOM, BrewLOGIC, BrewMETER, Brew Better Not Bitter, BrewWISE, BrewWIZARD, BUNN Espress, BUNN Family Gourmet, BUNN Gourmet, BUNN Pour-O-Matic, BUNN, BUNN with
the stylized red line, BUNNlink, Bunn-OMatic, Bunn-O-Matic, BUNNserve, BUNNSERVE with the stylized wrench design,
Cool Froth, DBC, Dr. Brew stylized Dr. design, Dual, Easy Pour, EasyClear, EasyGard, FlavorGard, Gourmet Ice, Gourmet
Juice, High Intensity, iMIX, Infusion Series, Intellisteam, My Café, Phase Brew, PowerLogic, Quality Beverage Equipment
Worldwide, Respect Earth, Respect Earth with the stylized leaf and coffee cherry design, Safety-Fresh, savemycoffee.com,
Scale-Pro, Silver Series, Single, Smart Funnel, Smart Hopper, SmartWAVE, Soft Heat, SplashGard, The Mark of Quality in
Beverage Equipment Worldwide, ThermoFresh, Titan, trifecta, TRIFECTA (sylized logo), Velocity Brew, Air Brew, Beverage
Bar Creator, Beverage Profit Calculator, Brew better, not bitter., Build-A-Drink, BUNNSource, Coffee At Its Best, Cyclonic
Heating System, Daypart, Digital Brewer Control, Element, Milk Texturing Fusion, Nothing Brews Like a BUNN, Picture
Prompted Cleaning, Pouring Profits, Signature Series, Sure Tamp, Tea At Its Best, The Horizontal Red Line, Ultra are either
trademarks or registered trademarks of Bunn-O-Matic Corporation. The commercial trifecta® brewer housing configuration is a trademark of Bunn-O-Matic Corporation.
Page 2
42770 031314
Contents
Circuit Breaker
.....................................................10
Fuse and Fuse Holder ........................................... 11
Contactor
..............................................................12
Control Thermostat ............................................... 14
Limit Thermostat ...................................................16
Thermal Cut-off ................................................... 17
Tank Heater(s)
.......................................................18
Liquid Level Board and Level Probe .................... 20
Digital Timer (Late Models) ................................... 22
Timer (Early Models).............................................24
Pump ....................................................................25
Relay ................................................................... 28
Solenoid ............................................................... 30
Transformer ..........................................................32
Master ON/OFF Switch (Late Models) ...................33
ON/OFF Switch ...................................................... 34
Start Switch (Brew) ............................................... 36
Selector Switch (Half Batch) .................................38
Schematic Wiring Diagrams ..................... 40 thru 56
Page 3
42770 072016
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 person-
nel.
• All electronic components have 120 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 brewer is heated at all times. Keep away from combustibles.
WARNING – • Exercise extreme caution when servicing electrical equipment.
• Unplug the brewer when servicing, except when electrical tests are specified.
• Follow recommended service procedures
• Replace all protective shields or safety notices
PROBLEM
Brew cycle will not start
PROBABLE CAUSE
1. No water
2. No power or incorrect voltage to
the brewer
REMEDY
Water lines and valves to the brewer
must be open.
(A1) Check the terminal block for
120 volts ac across the red and white
terminals and the black and white
terminal on three wire 102/208 volt
or 120/240 volt models.
(A2) Check the terminal block for 208
volts ac, 230 volts ac or 240 volts
ac on "A Series" brewers across the
red and black terminals on two wire
single phase 208 volt, 230 volt and
240 volt models.
(A3) Check the terminal block for 208
volts ac, 240 volts ac, 380 volts ac
across the black and blue terminals,
the blue and red and the black and
red terminals on three wire three
phase 208 volt, 240 volt and 380
volt models.
Page 4
42770 012610
TROUBLESHOOTING (cont.)
PROBLEM
Brew cycle will not start (cont)
PROBABLE CAUSE
2. No power or incorrect voltage to
the brewer (cont)
3. Water level below pump housing.
(Water level in the hot water gauge
glass should be approximately half
full).
4. ON/OFF Switch
REMEDY
(A4) Check the terminal block for
440 volts ac across the black and
blue terminals, black and red terminals and the red and blue terminals
on four wire three phase 440 volt
models.
(B) Check circuit breakers or
fuses.
Be sure water shut-off valve is open
and that the in-line filters or strainers are not blocking water flow. (Do
not confuse water shut-off valve
with the manual fill and drain valve
underneath the brewer).
Refer to Service - ON/OFF Switch for
testing. See page 22
5. Start Switch
6. Relay
7. Timer
8. Pump
9. Solenoid Valve
10. Strainer
Refer to Service - Start Switches for
testing procedures. See page 29
Refer to Service - Relay for testing
procedures. See page 24
Refer to Service - Timer for testing
procedures. See page 31 or 33
Refer to Service - Pump for testing
procedures. See page 23
Refer to Service - Solenoid Valve for
testing procedures. See page 27
(A) Direction of flow arrow must be
pointing towards brewer.
(B) Remove the strainer and check
for obstructions. Clear or replace.
Brew cycle starts with brew lockout
relay engaged.
1. Relay
Page 5
Refer to Service - Relay for testing
procedures. See page 24
42770 012610
TROUBLESHOOTING (cont.)
PROBLEM
Tank not filling
PROBABLE CAUSE
1.ON/OFF Switch (This switch
must be in the "ON" position for
the refill circuit to operate.
2. No water
3. Solenoid Valve
4. Probe
5. Liquid Level Board
REMEDY
Refer to Service - ON/OFF Switch
for testing procedures. See page
22
Be sure water shut-off is open and
that in-line filters or strainers are
not blocking water flow. (Do not
confuse water shut-off valve with
the manual fill and drain valve
underneath brewer).
Refer to Service - Solenoid Valve
for testing procedures. See page
27
Refer to Service - Probe for testing
procedures. See page 20
Refer to Service - Liquid Level
Board for testing procedures. See
page 20
Water running out of the overflow
1.Brewer not level
2. Solenoid Valve
3. Liquid Level Board
4. Probe
5. Manual fill and drain valve underneath brewer open.
Brewer must be level and installed
on a sturdy structure.
Refer to Service - Solenoid Valve
for testing procedures. See page
27
Refer to Service -Liquid Level
Board for testing procedures. See
page 20
Refer to Service - Probe for testing
procedures. See page 20
Be sure valve is closed.
Page 6
42770 012610
TROUBLESHOOTING (cont.)
PROBLEM
Water not hot
Circuit breaker keeps tripping
PROBABLE CAUSE
1. Limit Thermostat
CAUTION - Do not eliminate or
bypass limit thermostat. Use only
Bunn-O-Matic replacement part
#29329.1000
2. Control Thermostat
3. Tank Heater(s)
4. Contactor
1. Circuit Breaker
REMEDY
Refer to Service - Limit Thermostat for testing procedures. See
page19
Refer to Service - Control Thermostat for testing procedures.
See page 17
Refer to Service - Tank Heater for
testing procedures. See page 30
Refer to Service - Contactor for
testing procedures. See page 15
Refer to Service - Circuit Breaker
for testing procedures. See page
14
Water keeps running from swing
spout
Inconsistent coffee yield
Funnels overflow
2. Tank Heater(s)
1. Timer
2. Start Switch
1. Timer
2. Solenoid Valve
3. Lime build-up in swing spout
and pump tubing.
1. Filters
Refer to Service - Tank Heater for
testing procedures. See page 30
Refer to Service - Timer for testing
procedures. See page 31 or 33
Refer to Service - Start Switch for
testing procedures. See page 29
Refer to Service - Timer for testing
procedures. See page 31 or 33
Refer to Service - Solenoid Valve
for testing procedures. See page
27
Remove swing spout and insert
deliming rod down into pump
tubing as far as possible.
®
Use Bunn
filters made for the
U3 brewer.
2. Hole in bottom of funnel obstructed.
Page 7
Remove obstruction.
42770 012610
TROUBLESHOOTING (cont.)
PROBLEM
Funnels overflow (cont.)
Coffee reservoir overflows
PROBABLE CAUSE
3. Pump - Flow Rate
4. Soft Water
1. Coffee reservoir not completely
empty before a brew cycle was
started.
2. Timer
REMEDY
Check pump flow rate with a watch.
Pump flow rate should be approximately 24 ounces in 15 seconds.
Be sure pump assembly is free of
any obstructions.
When using a water softener, a
coarse grind of coffee may be
preferred. If required, a bypass
system is available as an optional
feature.
Be sure coffee reservoir is empty
before brew cycle is started.
Refer to Service -Timer for testing
procedures. See page 31 or 33
Brewer is making unusual noises
3. Pump - Flow Rate
1. Solenoid Valve
2. Plumbing lines
3. Water supply
Check pump flow rate with a watch.
Pump flow rate should be approximately 24 ounces in 15 seconds.
Be sure pump assembly is free of
any obstructions.
The nut on the solenoid must
be tight or it will vibrate during
operation.
Plumbing lines should not be resting on the counter top.
(A) The brewer must be connected
to a cold water line.
(B) Water pressure to the brewer
must not exceed 90 psi (620 kPa).
Install a regulator if necessary to
lower the pressure to approximately 50 psi (345 kPa).
4. Tank Heater(s)
Page 8
Remove and clean lime off the tank
heater. See page 30
42770 012610
This section provides procedures for testing and
replacing various major components used in this
brewer should service become necessary. Refer to
Troubleshooting for assistance in determining the
cause of any problem.
WARNING - Inspection, testing, and repair of electri-
cal equipment should be performed only by qualified
service personnel. The brewer should be unplugged
when servicing, except when electrical tests are re-
quired and the test procedure specifically states to
plug in the brewer.
COMPONENT ACCESS - SRU
WARNING - Disconnect the brewer from the power
source before the removal of any panel or the replacement of any component.
The control thermostat, limit thermostat, pump,
solenoid valve, liquid level probe and tank heater are
accessible by removal of the swing spout, front cupola
cover, rear cupola cover and the cupola.
Disconnect the swing spout nut from the swing
spout base fitting. Remove swing spout.
COMPONENT ACCESS - U3
WARNING - Disconnect the brewer from the power
source before the removal of any panel or the replace-
ment of any component.
All components are accessible by the removal of
the swing spout, front cupola cover, rear cupola cover
and the cupola.
Disconnect the swing spout nut from the swing
spout base fitting. Remove swing spout.
Remove the four #8-32 screws, two on the front and
rear, securing front and rear cupola covers to the
cupola.
Slip cupola off of the component bracket.
Remove the four #8-32 screws, two on each side,
securing the side covers to the cupola.
Slip cupola off of the component bracket.
The on/off switch, selector switch, start switch,
timer, contactor and liquid level control board are accessible by removal of the front lower panel.
Remove the four #8-32 screws securing the front
access panel to the base.
The circuit breaker, fuse and fuse holder are accessible by removal of the rear utility cover.
Remove the six #8-32 screws securing the rear
utility cover to the housing.
FIG. 9a COMPONENT ACCESS
P1317.30
Page 9
P2053.25
FIG. 9b COMPONENT ACCESS
42770 012610
CIRCUIT BREAKER (120/208V and 120/240V Three
J2
S
ET
L
OC
K
L
O
CK
S
E
T
TL1
TL2
TL3
TL4
TL5
J1
Wire Models and 440V Four Wire Models)
P2209.60
FIG. 10a CIRCUIT BREAKER
Location: U3
pump assembly. With a voltmeter, check the voltage
across the black wire and the white wire. Connect
the brewer to the power source. The indication
must be:
a) 120 volts ac for three wire 120/208 volt and
120/240 volt models.
b) 208 or 240 volts ac for four wire 440 volt mod-
els.
3. Disconnect the brewer from the power source.
If voltage is present as described, reconnect the white
wire to the pump assembly and proceed to #4. If voltage is not present as described, refer to the Wiring
Diagrams and check the brewer wiring harness.
4. With the black wire removed, remove the other
black wire from the circuit breaker.
5. Check for continuity across the terminals on the
circuit breaker.
The circuit breaker is located on the right rear of
the component bracket.
P2115.30
FIG. 10b CIRCUIT BREAKER
Location: SRU
The circuit breaker is located on the rear of the
urn, behind the rear utility cover.
Test Procedures:
1. Disconnect the brewer from the power source.
2. Disconnect the black wire from the main harness
from the circuit breaker and the white wire on the
If continuity is present as described the circuit breaker
is operating properly.
If continuity is not present as described, press the reset
button and repeat step 5, if continuity is not present
as described, replace the circuit breaker.
Removal and Replacement:
1. Remove wires from the circuit breaker.
2. Remove the nut securing the circuit breaker to the
component bracket.
3. Remove circuit breaker and discard.
4. Install new circuit breaker on component bracket
and secure with nut.
5. Refer to Fig. 10c and reconnect the wires.
BLK from Main
Harness
BLK from ON/
OFF Switch
FIG. 10c CIRCUIT BREAKER TERMINALS
P1723
Page 10
42770 012610
FUSE AND FUSE HOLDER (208V, 240V, 230V Two
Wire Models and 380V Three Wire Models)
P1731.55
FIG. 11a FUSE AND FUSE HOLDER
Location: U3
The fuse and fuse holder are located on the right
rear of the component bracket.
Test Procedures:
1. Disconnect the brewer from the power source.
2. Remove the cap and fuse from the fuse holder.
3. Remove fuse from the cap.
4. Check for continuity through the fuse.
If continuity is present as described, reinstall the fuse,
the fuse is operating properly.
If continuity is not present as described replace the
fuse.
Removal and Replacement:
Fuse:
1. Remove the cap from the fuse holder.
2. Remove fuse from the fuse holder, inspect, if blown
discard.
3. Install new 5 amp fuse in the fuse holder.
4. Reinstall fuse holder cap.
Fuse Holder:
1. Disconnect the wires from the rear of the fuse
holder.
2. Remove the nut securing the fuse holder to the
component bracket.
3. Push fuse holder through the hole in the component
bracket.
4. Install new fuse holder and fuse through the hole
in the component bracket and secure with nut.
5. Refer to Fig. 11c and reconnect the wires.
P2122.30
FIG. 11b FUSE AND FUSE HOLDER
Location: SRU
The fuse and fuse holder are located on the rear
of the urn behind the rear utility cover.
Page 11
BLK from ON/OFF Switch
(208V, 240V Two Wire
Models and 380V Three
Wire Models)
RED from ON/OFF Switch
(230V Two Wire Models)
BLK from Main Harness
(208V and 240V Two Wire
Models)
BLK from Transformer
(380V Three Wire Models)
RED from Main Harness
(230V Two Wire Models)
FIG. 11c FUSE HOLDER TERMINALS
P1331
42770 012610
CONTACTOR
J
2
S
E
T
L
O
C
K
L
O
C
K
S
E
T
T
L1
TL2
TL3
TL
4
T
L5
J1
P2209.60
FIG. 12a CONTACTOR
Location: U3
The contactor is located on the left front of the
component bracket.
2B. 208V or 240V TWO WIRE MODELS (Prior to
# U300004095), 208V and 240V THREE WIRE
MODELS
Disconnect the black wire from the contactor coil
to the limit thermostat and black wire from the red
wire on the main harness.
2C. 230V MODELS (S/N U300004095 - UP)
Disconnect the red wire from contactor coil to the
limit thermostat and the black wire from the main
harness.
3. Connect the brewer to the power source.
4. Check the voltage across the coil wire and the wire
from the main harness. The indication must be:
a) 120 volts ac for three wire 120/208, 120/240
volt and 380 volt models.
b) 230 volts ac for two wire 230 volt models.
c) 208 or 240 volts ac for two wire 208 or 240 volt
models.
d) 220 or 254 volts ac for four wire 280 or 440
volt models.
P2208.40
FIG. 12b CONTACTOR
Location: SRU
The contactor is located inside the front lower access panel, left of center on the component bracket.
Test Procedures:
1. Disconnect the brewer from the power source.
2A. 120/208V, 120/240V, 380V THREE WIRE MODELS,
380V and 440V FOUR WIRE MODELS
Disconnect the black wire from the contactor coil
to the limit thermostat and black wire from the
white wire on the main harness.
5. Disconnect the brewer from the power source.
If voltage is present as described, proceed to #6.
If voltage is not present as described refer to the Wiring
Diagrams and check the brewer wiring harness.
6. Check for continuity between the black leads on
the contactor coil or the left and right terminals
on the contactor coil on 230V models.
If continuity is present as described, reconnect the
wires and proceed to #7.
If continuity is not present as described, replace the
contactor.
7. On all brewers, with a voltmeter, check the voltage
across the upper left terminal and the upper right
terminal on the contactor. Connect the brewer to
the power source. The indication must be:
a) 120 volts ac for three wire 120/208, 120/240
volt and 380 volt models.
b) 230 volts ac for two wire 230 volt models.
c) 208 or 240 volts ac for two wire 208 or 240 volt
models.
d) 220 or 254 volts ac for four wire 280 or 440
volt models.
8. Disconnect the brewer from the power source.
Page 12
42770 012610
CONTACTOR (cont.)
If voltage is present as described, proceed to #9.
If voltage is not present as described, refer to the Wiring
Diagrams and check the brewer wiring harness.
9. Check for continuity across the terminals on the
left side of the contactor by manually closing the
contacts. Continuity must not present when the
contact is released.
10. Check for continuity across the terminals on the
right side of the contactor by manually closing the
contacts. Continuity must not be present when the
contact is released.
BLK to Right Tank
Heater (T1)
BLK to Terminal
Block (L1)
RED to Left Tank
Heater (T2)
RED to Terminal
Block(L2)
BLK to left
Tank Heater
(L1)
If continuity is present as described, the contactor is
operating properly.
If continuity is not present as described, replace the
contactor.
Removal and Replacement:
1. Disconnect all the wires from the contactor.
2. Remove the two #8-32 screws securing the contactor to the contactor mounting bracket, remove
contactor and protective shield. Discard contactor.
3. Install new contactor with shield between mounting
bracket and contactor and secure with two #8-32
screws
4. Refer to Fig. 13a and reconnect the wires.
BLK Thermal Fuse
to Right Tank Heater
BLK to Terminal
Block (L1)
BLK to Terminal
Block (L2)
RED Thermal Fuse
to Left Tank Heater
RED to Terminal
BLK Thermal
Block (L2)
Fuse to Left
Tank Heater
RED to Right
Tank Heater
(L2)
BLK to Limit
Thermostat
WHI from Main Harness
(120/208V,120/240V,380V
Three Wire Models, 380V and
440V Four Wire Models)
RED from Main Harness
(208V, 240V Two Wire Models
and 208, 240V Three Wire
Models)
120/208V, 120/240V, 208V,
240V, 380V 440V MODELS
FIG. 13a CONTACTOR TERMINALS
Page 13
RED Thermal Fuse
to Right Tank
Heater
230V - CE Models
RED to Limit
Thermostat
P1725
42770 012610
CONTROL THERMOSTAT
Model
120/208V & 120
240V - 3 wire w/
ground single phase
Check Voltage Across
Black wire on thermostat
from main harness to white
wire in terminal block.
Voltage
120V
FIG. 14a CONTROL THERMOSTAT
P2209.60
Location: U3
The control thermostat is mounted on the right
front of the component bracket.
P2113.40
FIG. 14b CONTROL THERMOSTAT
Location: SRU
The control thermostat is mounted on the left front
of the top component bracket.
230V - 2 wire w/
ground single
phase
208V or 240V - 2
wire w/ground
single phase
280V or 440V - 4
wire w/ground 3
phase
380V - 3 wire w/
ground 3 phase
w/ stepdown
transformer
Red wire on thermostat
from main harness to black
wire in terminal block.
Black wire on thermostat
from main harness to red
wire in the terminal block.
Black wire on thermostat
from main harness to white
wire in terminal block.
Black wire on thermostat
from main harness to white
wire on step down transformer.
230V
208V or
240V
220V or
254V
120V
4. Disconnect the brewer from the power source.
If voltage is present as described, proceed to #5.
If voltage is not present as described, refer to the Wiring
Diagrams and check the brewer wiring harness.
5. Disconnect the black wires from the control ther-
mostat.
6. Check for continuity across the terminals on the
control thermostat with the control thermostat in
the "ON" position (fully clockwise), continuity must
not be present when the thermostat is in the "OFF"
position (fully counterclockwise).
If continuity is present as described, the control ther-
mostat is operating properly.
If continuity is not present as described, replace the
control thermostat.
Test Procedures:
1. Disconnect the brewer from the power source.
2. Locate the thermostat and the voltage check
points.
3. Connect the brewer to the power source.
Page 14
Removal and Replacement:
1. Disconnect the wires from the control thermostat.
2. Remove the thermostat capillary bulb by firmly
pulling up on the capillary at the component
bracket. This will disengage the grommet from
the component bracket.
3. Remove the #8-32 screw securing the control
thermostat and mounting bracket to the component
bracket. Remove control thermostat and bracket
as an assembly.
4. Remove knob from control thermostat.
5. Remove the two #6-32 screws securing the control
thermostat to the thermostat mounting bracket.
Remove and discard thermostat.
6. Install new control thermostat on thermostat
42770 012610
CONTROL THERMOSTAT (cont.)
mounting bracket and secure with two #6-32
screw.
7. Install knob on thermostat.
8. Install thermostat and mounting bracket on the
component bracket and secure with one #8-32
screw.
9. Carefully bend the capillary tube so that the tube
and bulb inside the brewer are in the vertical position.
NOTE: The capillary tube must be clear of any electrical
termination and not kinked.
10. Refer to Fig. 7 and reconnect the wires.
11. Adjust the control thermostat as required.
Removal and Replacement:
1. Disconnect the wires from the control thermostat.
2. Remove the thermostat capillary bulb by firmly
pulling up on the capillary at the component
bracket. This will disengage the grommet from
the component bracket.
3. Remove the #8-32 screw securing the control
thermostat and mounting bracket to the component
bracket. Remove control thermostat and bracket
as an assembly.
4. Remove knob from control thermostat.
5. Remove the two #6-32 screws securing the control
thermostat to the thermostat mounting bracket.
Remove and discard thermostat.
6. Install new control thermostat on thermostat
mounting bracket and secure with two #6-32
screw.
7. Install knob on thermostat.
8. Install thermostat and mounting bracket on the
component bracket and secure with one #8-32
screw.
9. Carefully bend the capillary tube so that the tube
and bulb inside the brewer are in the vertical position.
NOTE: The capillary tube must be clear of any electrical
termination and not kinked.
10. Refer to Fig. 15a and reconnect the wires.
11. Adjust the control thermostat as required.
BLK from Main Harness (All Models Except 230V CE Models
RED from Main
Harness (230V CE
Models)
BLK to Limit Thermostat
(All Models Except 230V CE
Models
RED to Limit Thermostat
(230V CE Models)
P1730.80
FIG. 15a CONTROL THERMOSTAT TERMINALS
Page 15
42770 012610
LIMIT THERMOSTAT
Removal and Replacement:
1. Remove the wires from the limit thermostat terminals.
2. Carefully slide the limit thermostat out from under
the retaining clip and remove the limit thermostat.
3. Carefully slide the new limit thermostat into the
retaining clip.
4. Refer to Fig. 16c and reconnect the wires.
FIG. 16a LIMIT THERMOSTAT
P2209.60
Location: U3
The limit thermostat is located on the center front
of the component bracket behind the timer mounting
bracket.
P1732
FIG. 16b LIMIT THERMOSTAT
Location: SRU
The limit thermostat is located on the center rear
of the component bracket behind the tank heater.
BLK to Contactor
(All Models Except
230V CE Models)
Red to Contactor
(230V CE Models)
BLK to Control
Thermostat (All
Models Except
230V CE Models)
RED to Control
Thermostat
(230V Models)
FIG. 16c LIMIT THERMOSTAT TERMINALS
P1800
Test Procedures:
1. Disconnect the brewer from the power source.
2. Disconnect the black wires or the red wires from
the limit thermostat.
3. With an ohmmeter, check for continuity across
the limit thermostat terminals.
If continuity is present as described, the limit thermostat
is operating properly.
If continuity is not present as described, replace the
limit thermostat.
Page 16
42770 012610
THERMAL FUSES (230V-CE MODELS ONLY)
J
2
S
ET
L
O
CK
L
O
C
K
S
E
T
TL
1
T
L2
T
L3
T
L4
TL5
J1
FIG. 17a THERMAL FUSES
Location: U3
The thermal fuses are mounted on the tank heater
terminals and the contactor terminals.
Test Procedures:
1. Disconnect the brewer from the power source.
2. Disconnect the thermal fuse from the tank heater
terminal and the contactor terminal.
3. Check for continuity across the terminals on the
ends of the thermal fuse.
If continuity is present as described, the thermal is
operating properly.
If continuity is not present as described, replace the
thermal fuse.
Removal and Replacement:
1. Disconnect the thermal fuse from the tank heater
terminal and the contactor and discard.
2. Connect the new thermal fuse to the tank heater
terminal and the contactor terminal.
P1750.65
FIG. 17b THERMAL FUSES
Location: SRU
The thermal fuses are mounted on the tank heater
terminals.
P2121.40
Page 17
42770 012610
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