TB3/TB6 Series
Including: TB3; TB3-LP;
TB3Q; TB3Q-LP; TB6; TB6Q
STARTING WITH SERIAL NUMBER: TU00020000
SERVICE & REPAIR MANUAL
BUNN-O-MATIC CORPORATION
POST OFFICE BOX 3227
SPRINGFIELD, ILLINOIS 62708-3227
PHONE: (217) 529-6601 FAX: (217) 529-6644
41722.0000A 07/09 ©2009 Bunn-O-Matic Corporation
BUNN-O-MATIC COMMERCIAL PRODUCT WARRANTY
Bunn-O-Matic Corp. (“BUNN”) warrants equipment manufactured by it as follows:
1) All equipment other than as specified below: 2 years parts and 1 year labor.
2) Electronic circuit and/or control boards: parts and labor for 3 years.
3) Compressors on refrigeration equipment: 5 years parts and 1 year labor.
4) Grinding burrs on coffee grinding equipment to grind coffee to meet original factory screen sieve analysis:
parts and labor for 3 years or 30,000 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, damage or casualty. 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.
BrewWISE, BrewLOGIC, BrewMETER, BrewWIZARD, Bunn Gourmet, BUNN Gourmet Ice, BUNN Pour-O-Matic,
BUNN, Bunn-OMatic, Bunn-O-Matic, BUNNlink, BUNNserve, BUNNSERVE, BUNN Espress, Cool Froth, DBC, Dr.
Brew, Dual, EasyClear, EasyGard, Easy Pour, FlavorGard, Gourmet Ice, Gourmet Juice, High Intensity, IMIX, Infusion Series, Intellisteam, Quality Beverage Equipment Worldwide, The Mark of Quality in Beverage Equipment
Worldwide, My Café, PowerLogic, Safety-Fresh, Scale-Pro, Silver Series, Single, Smart Funnel, Smart Hopper,
SmartWAVE, Soft Heat, SplashGard, System III, ThermoFresh, 392, AutoPOD, AXIOM, Beverage Profit Calculator, Beverage Bar Creator, BUNNsource, Coffee At Its Best, Digital Brewer Control, Nothing Brews Like a BUNN,
Pouring Profits, Pulse Wave, Signature Series, Smart Heat, Tea At Its Best, The Horizontal Red Line, Titan, Ultra,
are either trademarks or registered trademarks of Bunn-O-Matic Corporation.
Page 2
41722 012609
Contents
Trouble Shooting .............................................................................................................. 4
Component Acess ......................................................................................................... 10
Control Thermostat ........................................................................................................ 10
Limit Thermostat ............................................................................................................ 12
Tank Heater .................................................................................................................... 13
Lighted ON/OFF Switch .................................................................................................. 14
Non Lighted ON/OFF Switch ........................................................................................... 15
Start Switches ................................................................................................................ 16
Inlet Solenoids ............................................................................................................... 17
Dual Timer (TB3/TB6) .................................................................................................... 18
Digital Timer (TB3Q/TB6Q) ............................................................................................ 20
Schematic Wiring Diagrams .......................................................................................... 22
Page 3
41722 070209
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,andrepairofelectricalequipmentshouldbeperformedonlybyqualiedservicepersonnel.
• Allelectroniccomponentshave120voltacandlowvoltagedcpotential on their terminals. Shorting of
terminals or the application of external voltages may result in board failure.
• Intermittentoperationofelectroniccircuitboardsisunlikely.Boardfailurewillnormallybepermanent.If
an intermittent condition is encountered, the cause will likely be a switch contact or a loose connection at a
terminal or crimp.
• Solenoidremovalrequiresinterruptingthewatersupplytothevalve.Damagemayresultifsolenoidsare
energized for more than ten minutes without a supply of water.
• Theuseoftwowrenchesisrecommendedwheneverplumbingttingsaretightenedorloosened.Thiswill
help to avoid twists and kinks in the tubing.
• Makecertainthatallplumbingconnectionsaresealedandelectricalconnectionstightandisolated.
• Thisbrewerisheatedatalltimes.Keepawayfromcombustibles.
WARNING – • Exerciseextremecautionwhenservicingelectricalequipment.
• Unplugthebrewerwhenservicing,exceptwhenelectricaltestsarespecied.
• Followrecommendedserviceprocedures
• Replaceallprotectiveshieldsorsafetynotices
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 wire crimps for
120 volts across the black and
white terminals on two wire 120
volt brewers.
(A2) Check the wire crimps for
200 volts on "B Series" brewers
or 230 volts on "A Series" brewers across the red and black
terminals.
(B) Check circuit breakers or
fuses.
Page 4
41722 070209
TROUBLESHOOTING (cont.)
PROBLEM
Brew cycle will not start (cont.)
PROBABLE CAUSE
3. ON/OFF Switch
4. Start Switch
5. Timer
6. Solenoid Valve
7. Water strainer/flow control
(If equipped)
REMEDY
Refer to Service - ON/OFF
Switch for testing.
Refer to Service - Start Switch
for testing procedures.
Refer to Service - Timer for testing procedures.
Refer to Service - Solenoid Valve
for testing procedures.
(A) Direction of flow arrow must
be pointing towards brewer.
(B) Remove the strainer/flow
control and check for obstructions. Clear or replace.
Water is not hot
1. (A) Limit Thermostat
(B) Thermal Cut-Off (230V)
CAUTION - Do not eliminate
or bypass limit thermostat or
thermal cut-off. Use only BOM
replacement parts.
2. Control Thermostat
3. Tank Heater
Refer to Service - Limit Thermostat for testing procedures.
Thermal Cut-Off for testing
procedures.
Refer to Service - Control Thermostat for testing procedures.
Refer to Service - Tank Heater
for testing procedures.
Page 5
41722 070209
TROUBLESHOOTING (cont.)
PROBLEM
Inconsistent beverage level in
dispenser
PROBABLE CAUSE
1. Strainer /flow control
(If equipped)
2. Syphon System
3. Lime Build-up
CAUTION - Tank and tank components should be delimed
regularly depending on local
water conditions. Excessive mineral build-up on stainless steel
surfaces can initiate corrosive
reactions resulting in serious
leaks.
REMEDY
(A) Direction of flow arrow must
be pointing towards the brewer.
(B) Remove the strainer/flow
control and check for obstruction. Clear or replace.
The brewer must be level or
slightly lower in front to syphon
properly.
Inspect the tank assembly for
excessive lime deposits. Delime
as required.
Consistently low beverage level
in the dispenser
Spitting or excessive steaming
4. Water Pressure
1. Timer
2. Strainer/flow Control
(If equipped)
1. Lime Build-up
CAUTION - Tank and tank components should be delimed
regularly depending on local
water conditions. Excessive mineral build-up on stainless steel
surfaces can initiate corrosive
reactions resulting in serious
leaks.
Page 6
The water pressure to the brewer
must be at least 20 psi (138kPa)
and minimum 1.0 gpm flow rate.
Timer dial must indicate at least
two minutes and fifteen seconds.
Refer to Operating Manual.
(A) Direction of flow arrow must
be pointing towards brewer.
(B) Remove the strainer/flow
control and check for obstructions. Clear or replace.
Inspect tank assembly for excessive lime deposits. Delime as
required.
41722 070209
TROUBLESHOOTING (cont.)
PROBLEM
Spitting or excessive steaming
(cont.)
Dripping from sprayhead
PROBABLE CAUSE
2. Control Thermostat
1. Syphon System
2. Lime Build-up
CAUTION - Tank and tank components should be delimed
regularly depending on local
water conditions. Excessive mineral build-up on stainless steel
surfaces can initiate corrosive
reactions resulting in serious
leaks.
3. Solenoid Valve
REMEDY
Refer to Service - Control Thermostat for testing procedures.
The brewer must be level or
slightly lower in front to syphon
properly.
Inspect the tank assembly for
excessive lime deposits. Delime
as required.
Remove the solenoid valve and
clear any obstructions. Rebuild
or replace the valve if necessary.
Water flows into tank continuously (ON/OFF Switch "ON")
Water flows into tank continuously (ON/OFF Switch "OFF")
Beverage overflows dispenser
1. Timer
1. Solenoid Valve
1.Dispenser
2. Timer
3. Solenoid Valve
Refer to Service - Timer for testing procedures.
Remove the Solenoid Valve and
clean any obstruction. Rebuild
or replace the valve if necessary.
The dispenser must be completely empty before starting a
brew cycle.
Refer to Service - Timer for testing procedures.
Remove the Solenoid Valve and
clean any obstruction. Rebuild
or replace the valve if necessary.
Page 7
41722 070209
TROUBLESHOOTING (cont.)
PROBLEM PROBABLE CAUSE
Weak beverage
1. Filter Type
2. Coffee Grind
3. Sprayhead
4. Funnel Loading
5. Water Temperature
REMEDY
BUNN® paper filters must be used
for proper extraction.
A fine or drip grind must be used
for proper extraction.
A six-hole stainless steel sprayhead must be used for proper
extraction.
The BUNN® paper filter must be
centered in the funnel and the
bed of ground leveled by gentle
shaking.
Place an empty funnel on an empty
dispenser beneath the sprayhead.
Initiate a brew cycle and check the
water temperature immediately
below the sprayhead with a thermometer. The reading should not
be less than 200°F (93°C). Adjust
the control thermostat to increase
the water temperature. Replace if
necessary.
Dry coffee grounds remain in the
funnel
Brewer is making unusal noises
1. Funnel Loading
1. Solenoid
2. Plumbing Lines
3. Water Supply
Page 8
The BUNN® paper filter must be
centered in the funnel and the
bed of grounds leveled by gently
shaking.
The nut on the solenoid must
be tight or it will vibrate during
operation.
Plumbing lines should not 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 working pressure to approximately 50 psi (345 kPa).
41722 070209
TROUBLESHOOTING (cont.)
PROBLEM
PROBABLE CAUSE
REMEDY
Brewer is making unusal noises
(cont.)
4. Tank Heater
Remove and clean lime off the
tank heater.
Page 9
41722 070209
SERVICE
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 electrical equipment should be performed only by qualified
service personnel. The brewer should be unplugged
when servicing, except when electrical tests are required and the test procedure specifically states to
plug-in the brewer.
COMPONENT ACCESS
WARNING - Disconnect the brewer from the power
source before the removal of any panel or the replacement of any component.
All components are accessible by the removal of
the top cover, front inspection panel, and rear panel.
CONTROL THERMOSTAT
FIG. 10-2 CONTROL THERMOSTAT
Location:
The control thermostat is located in the hood.
Test Procedures:
1. Disconnect the brewer from the power source.
2. Locate the blue wire on the control thermostat.
3. Check the voltage across the blue/black wire on
the control thermostat and the white wire on the
tank heater on 120V models or red wire on the
tank heater on two wire 200V or 230V models
with a voltmeter. Connect the brewer to the power
source. The indication must be:
a) 120 volts ac for two wire 120 volt models.
b) 200 to 230 volts ac for two wire 200 or 230
volt models.
4. Disconnect the brewer from the power source.
FIG. 10-1 COMPONENT ACCESS
Page 10
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. Locate the black wire on the control thermostat.
6. Gently remove the capillary bulb and grommet
from the tank.
7. Check the voltage across the black wire of the
control thermostat and the white wire on the tank
heater on 120V models or red wire on the tank
heater on two wire 200V or 230V models with a
voltmeter when the control thermostat is turned
fully clockwise. Connect the brewer to the power
(CONTINUED)
41722 070209
SERVICE (cont.)
CONTROL THERMOSTAT (cont.)
source. The indication must be:
a) 120 volts ac for two wire 120 volt models.
b) 200 to 230 volts ac for two wire 200 volt or 230
volt models.
8. Disconnect the brewer from the power source.
If voltage is present as described, reinstall the capillary
tube into the tank to the line 4.5" above the bulb, the
control thermostat is operating properly.
If voltage is not present as described, replace the
thermostat.
Removal and Replacement:
1. Disconnect the control thermostat wires.
2. Remove the thermostat capillary bulb by firmly
pulling-up on the capillary at the tank lid. This will
disengage the grommet from the tank lid.
3. Remove the one #6-32 screw securing the control
thermostat to the component bracket inside the
hood.
4. Slide the grommet to the line 4.5" above the bulb
on the new capillary tube.
5. Insert the capillary bulb through the hole in the
tank lid and press the grommet firmly and evenly
so that the groove in the grommet fits into the tank
lid.
6. Carefully bend the capillary tube so that the tube
and bulb inside the tank are in the vertical posi-
tion.
FIG. 11-1 CONTROL THERMOSTAT TERMINALS
NOTE - The capillary tube must be clear of any electrical termination and not kinked.
7. Using one #6-32 screw, secure the control thermo-
stat to the component bracket inside the hood.
8. Adjust the control thermostat as required.
Page 11
FIG. 11-2 REPLACEMENT CONTROL THERMOSTAT
41722 070209
SERVICE (cont.)
LIMIT THERMOSTAT
If continuity is present as described, the limit thermostat
is operating properly.
If continuity is not present as described, replace the
limit thermostat.
Removal and Replacement:
1. Remove all wires from limit thermostat terminals.
2. Carefully slide the limit thermostat out from under
the retaining clip and remove limit thermostat.
3. Carefully slide the new limit thermostat into the
retaining clip.
4. Refer to the schematics when reconnecting the
wires.
FIG. 12-1 LIMIT THERMOSTAT
Location:
The limit thermostat is located inside the rear of
the hood on the tank lid.
Test Procedures:
1. Disconnect the brewer from the power source.
2. Disconnect the blue and black wires from the limit
thermostat.
3. Check for continuity across the limit thermostat
terminals with a ohmmeter.
to Tank
Heater Switch
Lead from
Control Thermostat
FIG. 12-2 LIMIT THERMOSTAT TERMINALS
Page 12
41722 070209
SERVICE (cont.)
TANK HEATER
FIG.13-1TANKHEATER
Location:
The tank heater is located inside the tank and
secured to the tank lid.
Test Procedures:
1. Disconnect the brewer from the power supply.
2. Turn on thermostat. Check the voltage across the
black and white wires on 120 volt models or the
black and red wires for 200 volt models and 230
volt models with a voltmeter. Connect the brewer
to the power source. The indication must be:
a) 120 volts ac for two wire 120 volt 20 amp
models .
b) 200 to 230 volts ac for two wire 200 or 230 volt
models.
3. Disconnect the brewer from the power source.
If voltage is present as described, proceed to #4
If voltage is not present as described, refer to the Wiring Diagrams and check wiring harness.
HEATER RESISTANCE
1680W-120V 7.9 - 9.2
1680W-100V 5.5 -6.4
1680W-230V 29.0 -33.7
TERMINAL TO SHEATH - INFINITE (OPEN)
If resistance is not present as described, replace the
tank heater.
NOTE- If any resistance is read between sheath and
either terminal, remove and inspect heater for
cracks in the sheath.
Removal and Replacement:
1. Disconnect the brewer from the power supply.
2. Disconnect the water supply from the brewer.
3. Disconnect the wires from the limit thermostat.
4. Disconnect the wires from the tank heater terminals.
5. Remove sprayhead and the hex nut securing the
sprayhead tube to the hood. Set aside for reassembly.
6. Remove the six #10 screws securing the tank lid
to the tank.
7. Remove the tank lid with limit thermostat, sprayhead tube and tank heater.
8 Remove the two hex nuts securing the tank heater
to the tank lid. Remove tank heater with gaskets
and discard.
9. Install new tank heater with gaskets on the tank
lid and secure with two hex nuts.
10. Install tank lid with limit thermostat, sprayhead
tube and tank heater using six #10 screws.
11. Secure sprayhead tube to hood using hex nut
removed in step 4.
12. Install sprayhead.
15. Reconnect the wires to the limit thermostat and
tank heater.
16. Reconnect the water and power supply.
4. Disconnect the wires from the tank heater terminals.
5. Check resistance value across tank heater terminals
and compare to chart.
If resistance is present as described, reconnect the
wires, the tank heater is ok.
Page 13
41722 070209
SERVICE (cont.)
LIGHTED ON/OFF SWITCH (TB3/TB3Q)
P/N 37080.0000
Orange light
FIG. 14-1 LIGHTED ON/OFF SWITCH
Location:
The ON/OFF switch is located in the front of the
hood, above and to the left of the brew funnel.
Test Procedure:
Brewers W/Out Half Batch or Sweetener Options
1. Disconnect the brewer from the power source.
2. Remove the wires from all four terminals.
3. Check for continuity across the two terminals on
the lower right of the switch (as shown). Continuity
must be present across these terminals in the ON
position.
Removal and Replacement:
1. Remove the wires from the switch terminals.
2. Compress the clips inside the hood and gently
push the switch through the opening.
3. Push the new switch into the opening and spread
the clips to hold the switch captive in the hood.
4. Refer to FIG. 14-2 when reconnecting the wires.
BLACK
WHITE
If continuity is present as described, reconnect the
wires, the switch is operating properly. If continuity
is not present as described, replace the switch.
NOTE: No continuity will show across the upper
left terminals of the lighted switch since the light is
neon.
WHT/VIO
P/N 37080.0000
2 WHT/VIO
FIG. 14-2 LIGHTED ON/OFF SWITCH TERMINALS
Page 14
41722 070209
SERVICE (cont.)
ON/OFF SWITCH-TB6/Q (Sweetner ½ Batch Option-TB3/Q)
P/N 03356.0003
Non Lighted
FIG. 15-1 NON LIGHTED ON/OFF SWITCH
WHI/VIO
BLACK
PINK
optional
½ batch
GRAY
Optional
½ batch
FULL/OFF/HALF-TB3/TB3Q
Location:
The switch is located on the front control panel.
Test Procedure:
1. Disconnect the brewer from the power source.
2. Disconnect the wires from switch terminals.
3. Check for continuity across the center and right
and across center and left terminals in rows one
through four when the switch is in the oposite
position.
If continuity is not present as described, replace the
switch.
If continuity is present as described, replace the wires
the switch is operating properly.
Removal and Replacement:
1. Remove the wires from the switch terminals.
2. Remove the clips on the switch bezel inside the
hood and gently push the switch through the
opening.
3. Push the new switch into the opening from inside
the hood and secure into place by pressing the
bezel through the front of the hood. Make sure
the clips on the switch bezel are locked around
the switch housing and spread the clips to hold
the switch captive in the hood.
4. Refer to FIG. 15-2 when reconnecting the wires.
WHI/VIO
WHITE
BRN/WHI
WHI/GRN
BLACK
WHI/VIO
UNSWEET/OFF/SWEET-TB3/TB3Q
w/SWEETENER & EMPTY DETECT
WHI/VIO
YELLOW
BLACK
BRN/BLK
LEFT/OFF/RIGHT-TB6
Page 15
FIG. 15-2 ON/OFF SWITCH TERMINALS
41722 070209
SERVICE (cont.)
START SWITCHES
P/N 37079.0000 P/N 37080.0001
Non Lighted Green ready light
FIG. 16-1 START SWITCHES
Location:
The start switch is located in the front of the hood,
above and to the right of the brew funnel.
WHI/YEL
to Timer T5
WHI/ORN
to Timer T3
P/N 37079.0000
Test Procedure:
1. Disconnect the brewer from the power source.
2. Remove the wires from all four terminals.
3. Check for continuity across the two terminals on
the right side of the switch when it is held in the
lower position. Continuity must not be present
across these terminals in the upper position.
4. Check for continuity across the two terminals on
the left side of the switch when it is held in the
lower position. Continuity must not be present
across these terminals in the upper position.
If continuity is not present as described, replace the
switch.
If continuity is present as described, reconnect the
wires, the switch is operating properly.
If continuity is not present as described, replace the
switch.
NOTE: No continuity will show across the left terminals
of the lighted switch since the light is neon.
WHI/YEL
to Timer T5
GREEN
WHI/ORN
to Timer T3
RED
P/N 37079.0000
WHI/YEL
to Timer T5
BLK
to T. Stat
Removal and Replacement:
1. Remove the wires from the switch terminals.
2. Compress the clips inside the hood and gently
push the switch through the opening.
3. Push the new switch into the opening and spread
the clips to hold the switch captive in the hood.
4. Refer to Fig. 16-2 when reconnecting the wires.
Page 16
WHI/ORN
to Timer T3
BLU/BLK
P/N 37080.0001
to T. Stat
FIG. 16-2 START SWITCH TERMINALS
41722 070209
SERVICE (cont.)
INLET VALVES
FIG. 17-1 INLET VALVES
Location:
The solenoid valve(s) are located inside the trunk
on the lower center part of the component bracket. Solenoids in the early models are located in the hood.
Test Procedures:
1. Check the solenoid valve for coil action. With "ON/
OFF" switch in the "ON' upper position press start
switch and listen carefully in the vicinity of the
solenoid valve for a" clicking" sound as the coil
magnet attracts.
2. Disconnect the brewer from the power source.
If the sound is heard as described and water will not
pass through the solenoid valve, there may be a blockage in the water line before the solenoid valve or, the
solenoid valve may require inspection for wear, and
removal of waterborne particles.
If the sound is not heard as described, proceed to
#3.
three wire 120/240 volt models.
b) 200 to 230 volts ac for two wire 200 or 230 volt
models.
7. Disconnect the brewer from the power source,
If voltage is present as described, proceed to #8
If voltage is not present as described, refer to Wiring
Diagrams and check brewer wiring harness.
8. Check for continuity across the solenoid terminals.
If continuity is present as described, reconnect the
white and black wire from the timer.
If continuity is not present as described, replace the
solenoid valve.
Removal and Replacement:
1. Disconnect the brewer from the power source.
2. Turn off the water supply to the brewer.
3. Remove the wires from the solenoid.
4. Disconnect the water lines to and from the solenoid
valve.
5. Remove the two screws securing the solenoid
mounting bracket to the component bracket.
6. Install new solenoid valve to the component
bracket.
7. Securely fasten the water lines to and from the
solenoid valve.
8. Refer to schematics when reconnecting the
wires.
3. Disconnect the brewer from the power source.
4. Connect a voltmeter across the solenoid terminals
(leave wires connected).
5. Connect the brewer to the power source. With the
"ON/OFF" switch in the "ON" upper position press
the start switch.
6. Check the voltage across the solenoid. The indication must be:
a) 120 volts ac for two wire 120 volt models and
Page 17
41722 070209
SERVICE (cont.)
BREW/DILUTION TIMER (TB3 & TB6)
FIG. 18-1 BREW/DILUTION TIMER
Location:
The timer is located in left side of the hood.
Test Procedure:
NOTE: Do not remove or install wires while timer board
is installed. Pressure applied to one side may cause
damage to the board.
1. Disconnect the brewer from the power source and
remove the top cover.
2. With a voltmeter, check the supply voltage across
terminals TL1 and TL2. Connect the brewer to the
power source. Turn on the "ON/OFF" switch. The
voltage must be:
a) 120 volts ac for two wire 120 volt models.
b) 200 to 230 volts ac on two wire 200 volt or
230 volt models.
3. Disconnect the brewer from the power source.
If voltage is present as described, the timer is operating properly.
If voltage is not present as described, disconnect the
brewer from the power source and replace the timer.
Removal and Replacement:
1. Remove the two #6-32 screws, lock washers and
spacers securing timer to bracket.
2. Disconnect all wires from the timer.
3. Refer to schematic and reconnect wires.
4. Install new timer to bracket with the two #6-32
screws, lock washers and spacers.
5. Adjust the timer as required.
SW1
J-1
TRM-1
TRM-2
TRM-3
TRM-4
TRM-5
TRM-6
J-4
If voltage is present as described, proceed to #4.
If voltage is not present as described, refer to the Wir-
ing Diagrams and check the wiring harness.
4. With a voltmeter, check the BREW output voltage
across terminals TL2 and TL4; and the DILUTION
output voltage across terminals TL2 and TL6.
Connect the brewer to the power source, turn on
the "ON/OFF" switch and press the "START" switch.
The voltage must be:
a) 120 volts ac for two wire 120 volt models.
b) 200 to 230 volts ac for two wire 200 volt or 230
volt models.
Page 18
FIG. 18-2 TIMER TERMINALS
Terminals:
J-1 ½ batch connector
J-4 Dilution delay time 1-2 (NORMAL), 3-4 (2x)
SW-1 Programming Enable/Disable
TRM-1 White/Violet L1 in from ON/OFF switch
TRM-2 White (Red) Neutral (L2)
TRM-3 White/Orange Start switch
TRM-4 White/Green Brew solenoid
TRM-5 White/Yellow Start switch
TRM-6 White/Blue Dilution solenoids
41722 070209
SERVICE (cont.)
BREW/DILUTION TIMER (TB3 & TB6) (cont.)
FIG. 19-1 BREW/DILUTION TIMER TRIACS
Triacs:
TH-1/MV-1 Brew solenoid
TH-2/MV-2 Dilution solenoid
Page 19
41722 070209
SERVICE (cont.)
DIGITAL BREW TIMER (TB3Q & TB6Q)
to the power source, turn on the "ON/OFF" switch
and press the "START" switch. The indication must
be as follows:
a) 120 volts ac for two wire 120 volt models.
b) 200 to 230 volts ac on two wire 200 volt or
230 volt models.
If voltage is not present as described, refer to the
Wiring Diagrams and check the wiring harness to the
start switch.
If start voltage is present as described (but no output
voltage), replace the timer.
FIG. 20-1 DIGITAL TIMER
Location:
The timer is located in left side of the hood.
Test Procedure
NOTE: Do not remove or install wires while timer board
is installed. Pressure applied to one side may cause
damage to the board.
1. Disconnect the brewer from the power source and
remove the top cover.
2. With a voltmeter, check the supply voltage across
terminals TL1 and TL2. Connect the brewer to the
power source. Turn on the "ON/OFF" switch. The
voltage must be:
a) 120 volts ac for two wire 120 volt models.
b) 200 to 230 volts ac on two wire 200 volt or
230 volt models.
3. Disconnect the brewer from the power source.
If voltage is present as described, proceed to #4.
If voltage is not present as described, refer to the Wir-
ing Diagrams and check the wiring harness.
Removal and Replacement:
1. Remove the two #6-32 screws, lock washers and
spacers securing timer to bracket.
2. Disconnect all wires from the timer.
3. Refer to schematic and reconnect wires.
4. Install new timer to bracket with the two #6-32
screws, lock washers and spacers.
5. Adjust the timer as required.
TRM-1
TRM-2
SW1
TRM-3
J-2
TRM-4
J-1
TRM-5
4. With a voltmeter, check the output voltage across
terminals TL1 and TL4. Connect the brewer to the
power source, turn on the "ON/OFF" switch and
press the "START" switch. The voltage must be:
a) 120 volts ac for two wire 120 volt models.
b) 200 to 230 volts ac for two wire 200 volt or 230
volt models.
If voltage is present as described, the timer is operating properly. If voltage is not present as described,
proceed to #5.
5. With a voltmeter, check the input start voltage
across terminals TL2 and TL5. Connect the brewer
Page 20
FIG. 20-2 DIGITAL TIMER
Terminals:
J-2 ½ batch connector
J-1 Multi batch (NOT USED IN TB SERIES)
SW-1 Programming Enable/Disable
TRM-1 White/Violet L1 from ON/OFF switch
TRM-2 White (Red) Neutral (L2)
TRM-3 White/Orange Start switch
TRM-4 White/Green Brew solenoid
TRM-5 White/Yellow Start switch
41722 070209
SERVICE (cont.)
DIGITAL BREW TIMER (TB3Q & TB6Q) (cont.)
FIG. 21-1 DIGITAL TIMER TRIACS
Triacs:
Q-1/MV-2 Brew solenoid output
MV-1 Line in
Page 21
41722 070209
SCHEMATIC WIRING DIAGRAM TB3Q
(OPTIONAL)
READY INDICATOR
BLU/BLK
BLK
SW. & THERMOSTAT
LIMIT
THERMOSTAT
L1
BLK
BLU/BLK
BLK
GREEN
TANK HEATER
N
WHI
WHI
WHI
WHI
SW2
"KEEP WARM HEATER"
SW1
BLK
WHI/VIO
WHI/VIO
WHI
WHI
WHI/ORA
WHI/GRN
WHI/YEL
SOL
1
2
3
4
5
BREW
TIMER
37234.0001A 08/04 © 2004 BUNN-O-MATIC CORPORATION
120 VOLTS AC
2 WIRE
SINGLE PHASE
SCHEMATIC WIRING DIAGRAM
TB3QA
LIMIT
THERMOSTAT
SW1
BREW
TIMER
BLK BLK
BLK
BLU/BLK RED
RED
RED
WHI WHI
WHI/VIO
WHI/VIO
WHI/GRN
WHI/GRN
WHI/ORN
L1
L2
GRN/YEL
WHI/YEL
37234.0003A 11/04 © 2004 BUNN-O-MATIC CORPORATION
230 VOLTS AC
2 WIRE
SINGLE PHASE
SOL
SW2
"KEEP WARM" HEATER
TANK HEATER
THERMAL
FUSE
THERMAL
FUSE
SW. &
THERMOSTAT
Page 22
41722 070209
SCHEMATIC WIRING DIAGRAM TB3, TB3B, TB3-LP
OPTIONAL
READY
INDICATOR
SWITCH &
THERMOSTAT
LIMIT
THERMOSTAT
"KEEP WARM" HEATER
ON/OFF SWITCH
37234.0007A 02/08 © 2008 BUNN-O-MATIC CORPORATION
START
SWITCH
DILUTION
BREW/DILUTION
TIMER
BREW
TANK HEATER
BLU/BLK BLKBLK
BLK
6 5 4 3 2 1
WHI
WHI WHI
WHI/VIO
WHI/BLU
WHI/ORN
WHI/YEL
WHI/VIO
WHI/VIO
WHI/GRN
WHI
WHI
L1 N
100 VOLTS AC
120 VOLTS AC
2 WIRE + GND
SINGLE PHASE
BLU/BLK BLK
GRN
Chassis Ground
Earth Ground
SOL
SOL
Page 23
41722 070209
37234.0008B 10/08 © 2008 BUNN-O-MATIC CORPORATION
SCHEMATIC WIRING DIAGRAM
TB3B W/HALF-BATCH
100 VOLTS AC
120 VOLTS AC
2 WIRE + GND
SINGLE PHASE
OPTIONAL
READY
INDICATOR
SWITCH &
THERMOSTAT
LIMIT
THERMOSTAT
"KEEP WARM" HEATER
START
SWITCH
BREW/DILUTION
TIMER
TANK HEATER
BLU/BLK BLKBLK
6 5 4 3 2 1
WHI
WHIWHI
WHI/VIO
WHI/BLU
WHI/ORN
WHI/YEL
WHI/VIO
WHI/VIO
WHI/GRN
WHI
L1 N
BLU/BLK BLK
GRN
Chassis Ground
Earth Ground
WHI/VIO
BLK
HALF/OFF/FULL SWITCH
SW1A SW1B SW1C SW1D
GRY
PNK
J1
1
3
½ BATCH
DILUTION
BREW
SOL
SOL
SCHEMATIC WIRING DIAGRAM TB3Q
LIMIT
THERMOSTAT
L1
BLK
BLU/BLK
N
WHI
WHI
WHI
WHI
"KEEP WARM HEATER"
SW1
BLK
WHI/VIO
WHI/VIO
WHI
WHI
WHI/ORA
WHI/GRN
WHI/YEL
1
2
3
4
5
BREW
TIMER
37234.0009B 06/08 © 2008 BUNN-O-MATIC CORPORATION
120 VOLTS AC
2 WIRE
SINGLE PHASE
SOL
SWITCH &
THERMOSTAT
TANK HEATER
BLU
BLK
GRNPOWER CORD
Chassis GroundEarth Ground
OPTIONAL
READY
INDICATOR
START SWITCH
BLU/BLK
BLK
Page 24
41722 070209
LIMIT
THERMOSTAT
BLU/BLK
TANK HEATER
"KEEP WARM" HEATER
START
L1
N
BLK
WHI
BLK
BREW
TIMER
WHI
WHI
GREEN
WHI/YEL
WHI/ORA
BLK
WHI/GRN
WHI/GRN
WHI/VIO
WHI
BRN/WHI
WHI/VIO
WHI
WHI
WHI/BLK
SCHEMATIC WIRING DIAGRAM TB3Q
W/SWEETENER & EMPTY BAG DETECT
120 VOLTS AC
2 WIRE
SINGLE PHASE
THERMOSTAT
SOL
SOL
12345
SOL
WHI/BLU
WHI/VIO
LOW PRESSURE
SWITCH
SWTNR
UNSWEET/OFF/SWEET
SOLD OUT INDICATOR
BLU
WHI/VIO
WHI/VIO
BLK
RELAY
37234.0010A 04/08 © 2008 BUNN-O-MATIC CORPORATION
2
5
7
N.O.COM.
SCHEMATIC WIRING DIAGRAM TB3A
OPTIONAL
READY
INDICATOR
SWITCH &
THERMOSTAT
LIMIT
THERMOSTAT
"KEEP WARM" HEATER
ON/OFF SWITCH
37234.0011A 10/08 © 2008 BUNN-O-MATIC CORPORATION
START
SWITCH
DILUTION
SOL
1
SOL
2
BREW
TANK HEATER
BLU
BLU/BLK
BLK
BLK BLK
BLK
RED
WHI WHI
WHI/VIO
WHI/BLU
WHI/ORN
WHI/YEL
RED
WHI/VIO
WHI/VIO WHI/GRN
RED
RED
L1 N
230 VOLTS AC
2 WIRE
SINGLE PHASE
THERMAL
FUSE
THERMAL
FUSE
BREW/DILUTION
TIMER
6 5 4 3 2 1
GRN
Chassis Ground
Earth Ground
Page 25
41722 070209
SCHEMATIC WIRING DIAGRAM TB6
WHI/ORN
BRN/BLK
LEFT/OFF/RIGHT SWITCH
SW1B
SW1DSW1CSW1A
TANK HEATER
BLK BLU/BLK
L1
WHI
BLK
BLK
WHI
SW. &
THERMOSTAT
WHI
120 VOLTS A C
2 WIRE
SINGLE PHASE
"KEEP WARM" HEATER
LIMIT
THERMOSTAT
WHI/VIO
WHI/YEL
WHI/BLU
TIMER
5
6
4
3
2
1
WHI/GRN
WHI
N
WHI
41974.0000A 03/09 © 2009 BUNN-O-MATIC CORPORATION
OPTIONAL
READY INDICATOR
BLU BLK
START SWITCH
DILUTION
LEFT RIGHT
BREW
YEL
YEL
SW2A
SOL
SOL SOL
GRN
Chassis Ground Earth Ground
Page 26
41722 070209
SCHEMATIC WIRING DIAGRAM TB6Q
WHI/ORN
BRN/BLK
LEFT/OFF/RIGHT SWITCH
SW1B
SW1DSW1CSW1A
TANK HEATER
BLK BLU/BLK
L1
WHI
BLK
BLK
WHI
SW. &
THERMOSTAT
WHI
120 VOLTS A C
2 WIRE
SINGLE PHASE
"KEEP WARM" HEATER
LIMIT
THERMOSTAT
WHI/VIO
WHI/YEL
TIMER
5
4
3
2
1
WHI/GRN
WHI
N
WHI
41975.0000A 03/09 © 2009 BUNN-O-MATIC CORPORATION
OPTIONAL
READY INDICATOR
BLU BLK
START SWITCH
DILUTION
LEFT RIGHT
BREW
YEL
YEL
SW2A
SOL
SOL SOL
GRN
Chassis Ground Earth Ground
Page 27
41722 070209
Loading...