Bunn-O-Matic TB3, TB3-LP Operation Manual

TB3

TB3-LP

OPERATING & SERVICE MANUAL

BUNN-O-MATIC CORPORATION

POST OFFICE BOX 3227

SPRINGFIELD, ILLINOIS 62708-3227

PHONE: [phone] FAX: [phone]

37235.0000D 05/06 ©2004 Bunn-O-Matic Corporation www.bunn.com

CONTENTS

Introduction .....................................................................2

Warranty ..........................................................................2

User Notices .....................................................................3

Electrical & Plumbing Requirements ............................... 4

Initial Set-Up ....................................................................5

Adjusting Brew Volumes .................................................. 6

Auto Sweetener Set-up .................................................... 6

Operating Controls ...........................................................7

Cleaning ...........................................................................8

Auto Sweetener Cleaning .................................................8

Tea Brewing ...................................................................... 8

Troubleshooting ............................................................... 9

Service ...........................................................................15

Wiring Diagrams ............................................................28

INTRODUCTION

This equipment will brew a three-gallon batch of fresh tea into an awaiting dispenser. The tea will be dispensed at

approximately room temperature to conserve ice. The brewer is only for indoor use on a sturdy counter or shelf.

BUNN-O-MATIC COMMERCIAL PRODUCT WARRANTY

Bunn-O-Matic Corp. (“BUNN”) warrants equipment manufactured by it as follows:

1) All equipment other than as specifi ed 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 fi rst.
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 [phone] or by writing to Post Offi ce Box 3227,
Springfi eld, 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 modifi cations 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 specifi ed 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 profi ts, 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.

Page 2

37235 050205

USER NOTICES

Carefully read and follow all notices on the equipment and in this manual. They were written for your pro­tection. All notices on the equipment should be kept in good condition. Replace any unreadable or damaged

#00831.0000

#37881.0000

#00656.0000

#06064.0000

WARNING

• FILL WATER TANK
BEFORE ENERGIZING

• DO NOT OVERLOAD
CIRCUIT

• KEEP AWAY FROM
COMBUSTIBLES

• DO NOT DEFORM
PLUG OR CORD

SEE

INSTRUCTIONS

• FAILURE TO COMPLY
RISKS EQUIPMENT
DAMAGE, FIRE OR
SHOCK

• BREWER ENERGIZED
UNLESS UNPLUGGED

#03408.0000

#03409.0000

#32540.0000

BREWERS

CAUTION – Disconnect the power source from the brewer prior to the removal
of any panel for the replacement or adjustment of any component.
NOTE: Check that the brewer is connected to water supply, the tank is properly
filled, and a funnel and server are in place, prior to setting or modifying batch
sizes.

1. Modifying batch sizes. To modify a batch volume, first check that the SET/

LOCK switch is in the “SET” position on the circuit board. If the brewer has
a batch selector switch, position it to the size to be changed.
To increase a batch size, Press and hold the START or BREW switch until
three clicks are heard. Release the switch and then press it again one or
more times. Each time the switch is pressed, two seconds are added to the
brew time period. Allow the brew cycle to finish in order to verify that the
desired volume has been achieved.
To decrease a batch size, Press and release the START or BREW switch
once for every two-second interval to be removed from the total brew time
period; then immediately press and hold down the START or BREW switch
until three clicks are heard. Release the switch. Allow the brew cycle to
finish in order to verify that the desired volume has been achieved.

2. Setting batch sizes. To set a batch volume, first check that the SET/LOCK

switch is in the “SET” position on the circuit board. Press and hold the
START or BREW switch until three distinct clicks are heard (this will take
approximately ten seconds), and then release the switch. (Failure to re­lease the switch within two seconds from the third click causes the volume
setting to be aborted). View the level of the liquid being dispensed. When
the desired level is reached, turn the ON/OFF switch to “OFF”. The brewer
remembers this volume and will continue to brew batches of this size until
the volume setting procedure is repeated. Empty server(s), turn selector
switch to positions that have yet to be set, and repeat batch setting proce­dure until all batch sizes are set.

NOTE: When brewing coffee, batch volumes will decrease due to absorption by
the coffee grounds.

32540.0000C 09/01 ©1999 Bunn-O-Matic Corporation

TIMER SETTING

Page 3

37235 050205

ELECTRICAL REQUIREMENTS

CAUTION - The brewer must be disconnected from the power source until specifi ed in Initial Set-Up.

120V model brewers require 2-wire, grounded service rated 120 volts ac, 15 amp, single phase, 60 Hz.
"A" model brewers require 2-wire, grounded service rated 230 volts ac, 10 amp, single phase, 50 Hz.
"B" model brewers require 2-wire, grounded service rated 100 volts ac, 15 amp, single phase, 60 Hz.

WARNING - If the power cord is ever damaged, it must be replaced by the manufacturer or its service agent with
a special cord available from the manufacturer or its service agent in order to avoid a hazard.

Proceed as follows:

Electrical Hook-Up

CAUTION – Improper electrical installation will damage electronic components.

1. An electrician must provide electrical service as specifi ed.

2. Using a voltmeter, check the voltage and color coding of each conductor at the electrical source.

3. Remove top cover from the brewer.

4. Rotate the control thermostat knob fully counterclockwise to the "OFF" position and replace the top cover.

5. Connect the brewer to the power source.

6. If plumbing is to be hooked up later be sure the brewer is disconnected from the power source. If plumbing
has been hooked up, the brewer is ready for Initial Set-Up.

PLUMBING REQUIREMENTS

These brewers must be connected to a cold water system with operating pressure between 20 (138) and 90
psi (620 kPa) from a 1⁄2" or larger supply line. A shut-off valve should be installed in the line before the brewer.
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 fi tting is 1⁄4" fl are.

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. A tight coil of copper tubing in the water line will facilitate moving the brewer
to clean the countertop. Bunn-O-Matic does not recommend the use of a saddle valve to install the brewer. The
size and shape of the hole made in the supply line by this type of device may restrict water fl ow.

This equipment must be installed to comply with the Basic Plumbing Code of the Building Offi cials
and Code Administrators International, Inc. (BOCA) and the Food Service Sanitation Manual of the
Food and Drug Administration (FDA). For models installed outside the U.S.A., you must comply with
the applicable Plumbing/Sanitation Code for your area.

1. Remove the shipping cap from the bulkhead fi tting on the rear of the brewer.

2. Flush the water line and securely attach it to the bulkhead fi tting on the rear of the brewer.

3. Turn on the water supply.

NOTE: TheFlow Control/Strainer assembly is internal, located inside the back panel.

Page 4

37235 050506

INITIAL SET-UP

CAUTION - The brewer must be disconnected from the power source throughout the initial set-up, except when

specifi ed in the instructions.

1. Remove the top lid from the brewer.

2. Rotate the control thermostat knob fully counterclockwise to the "OFF" position and replace the top lid.

3. Set the delay knob of the timer on the right side of the hood at eight minutes and the dilution knob of the

timer on the right side of the hood at three minutes and forty-fi ve seconds.

4. Remove the metal discharge tip from the funnel to speed up the set-up procedure. Insert the empty funnel

into the funnel rails.

5. Place an empty dispenser on the brewer base. Be sure the funnel discharge is directly above the hole in the

dispenser top lid.

6. Plug in the brewer and place the ON/OFF switch in the "ON" position. Momentarily press the start switch.

Water will fl ow into the tank and will shut off after three minutes. Press the start switch again. During the
second period, the tank will fi ll to its capacity and the excess will fl ow from the funnel into the dispenser.

7. Place the ON/OFF switch in the "OFF" position.

8. Disconnect the brewer from the power source and remove the top lid.

9. Rotate the control thermostat knob fully clockwise to

the "ON" position and replace the top lid.

10. Plug in the brewer and wait for the water in the tank

to heat to the proper temperature (approximately 20
minutes). Some water will drip from the funnel during
this time; this is due to expansion and should not occur
thereafter.

11. Place an empty dispenser under the funnel.

12. Place the ON/OFF switch in the "ON" position and press

the start switch. Empty the dispenser after water has
stopped fl owing from the funnel.

13. Allow the water in the tank to reheat to the proper

temperature.

14. Place the ON/OFF switch in the "ON" position and press

the start switch.

15. Place the ON/OFF switch in the "OFF" position im-

mediately after water stops fl owing from the funnel.
Check the water volume in the dispenser. It should be
seventy-six ounces.

16. If not, unplug the brewer, remove the top lid, and adjust

the timer on the left side of the hood as required. See
Adjusting Brew Volumes. Replace the top lid, plug in
the brewer, start, and measure another concentrate
cycle.

17. Repeat steps 13-16 until the proper water volume is achieved.

18. Unplug the brewer and remove the top lid.

19. Set the delay knob of the timer on the right side of the hood at three minutes and empty the dispenser.

20. Place the ON/OFF switch in the "ON" position, momentarily press the start switch, and allow both the con-

centrate and dilution cycles to occur.

oo

oo

Page 5

37235 050205

INITIAL SET-UP (cont.)

21. When all water stops fl owing, check the water volume in the dispenser. It should be 396 ounces.

22. If not, unplug the brewer and remove the top lid.

23. Adjust the dilution knob of the timer on the right side of the hood as required. Replace the top lid, plug in
the brewer, start, and measure another brew cycle.

24. Repeat steps 20-23 until the proper water volume is achieved.

25. Return the delay knob of the timer on the right side of the hood to eight minutes. Replace the top lid and
plug in the brewer.

26. Reinstall the metal discharge tip into the funnel.

27. Load the funnel with a BUNN® paper fi lter and approximately four ounces of loose tea leaves.

28. Place the ON/OFF switch in the "ON" position, momentarily press the start switch, and allow both the con­centrate and dilution cycles to occur. Observe the funnel discharge and the dilution streams near the end of
the brew cycle. The dilution stream should stop approximately thirty seconds after the funnel discharge has
stopped.

29. If not, unplug the brewer and remove the top lid.

30. Adjust the delay knob of the timer on the right side of the hood as required. Replace the top lid and plug in
the brewer.

31. Repeat steps 27-30 until the proper dilution timing is achieved.

ADJUSTING BREW VOLUMES

CAUTION - Disconnect the power source from the brewer prior to the removal of any panel for the replacement

or adjustment of any component.
NOTE: Prior to setting or modifying batch sizes, check that the brewer is connected to water supply, the tank is
properly fi lled, and a funnel and server are in place.

1. Modifying batch sizes. To modify a batch volume, fi rst check that the SET/LOCK switch is in the "SET" posi-
tion on the circuit board.

To increase a batch size. Press and hold the START or BREW switch until three clicks are heard. Release

the switch (Failure to release the switch within two seconds after the third click causes the volume setting to
be aborted and previous volume setting will remain in memory) and press it again one or more times. Each
time the switch is pressed, two seconds are added to the brew time period. Allow the brew cycle to fi nish in
order to verify that the desired volume has been achieved.

To decrease a batch size. Press and release the START or BREW switch once for every two-second interval

to be removed from the total brew time period; then immediately press and hold down the START or BREW
switch until three clicks are heard. Release the switch. (Failure to release the switch within two seconds after
the third click causes the volume setting to be aborted and previous volume setting will remain in memory).
Allow the brew cycle to fi nish in order to verify that the desired volume has been achieved.

2. Setting batch sizes. To set a batch volume, fi rst check that the SET/LOCK switch is in the "SET" position on
the circuit board. Press and hold the START or BREW switch until three distinct clicks are heard, and then
release the switch. (Failure to release the switch within two seconds after the third click causes the volume
setting to be aborted and previous volume setting will remain in memory). View the level of the liquid being
dispensed. When the desired level is reached, turn the ON/OFF switch to "OFF" (lower). The brewer remembers
this volume and will continue to brew batches of this size until the volume setting procedure is repeated.

NOTE: When brewing tea, batch volumes will decrease due to absorption by the tea grounds.

3. Setting programming disable feature. If it becomes necessary to prevent anyone from changing brew times
once programmed, you can set the SET/LOCK switch to the "LOCK" position. This will prevent any program­ming to be done until switch is once again placed in the "SET" position.

Page 6

37235 050205

AUTO SWEETENER SET-UP

CAUTION - The brewer must be disconnected from the power source throughout the Initial Set-Up, except

when specifi ed in the instructions.

1. Remove the top lid and rear panel.

2. Make sure the brewer water supply is off.

3. Connect sweetener hose from the bag in a box delivery system to the rear fi tting marked "Sweetener" .
IMPORTANT - System delivery pressure must be regulated between 30-40 psi. System also needs to deliver
product for at least 4 minutes without shutting off. Some pump systems shut off after a few minutes of continu­ous running.

4. Set the "Delay knob on the dilution timer to the 3 minute setting. (The minimum delay setting)

5. Plug brewer into the power source.

6. Place an empty reservoir under the dilution nozzle of the brewer.

7. Close the adjustment valve on the rear of the brewer fully (clockwise), then open (counterclockwise) 1/2

turn.

8. Set the selector switch to the "Sweetened" side and press the "Start" switch momentarily. (After approximately

3 minutes the sweetener will come out of the dilution nozzle.)

9. Run sweetener for 1 minute, then set selector switch to the "Off" position. The fl ow will stop.

10. Measure the amount of sweetener dispensed and calculate if the volume needs to be increased or decreased

(Dilution cycle is usually between 3 to 3 1/2 minutes).

11. If adjustment is needed, turning the adjustment valve clockwise decreases the amount of sweetener dis-

pensed and turning the adjustment valve counterclockwise increases the amount of sweetener dispensed.

12. Set the "Delay" knob on the dilution timer back to the 6 to 7 minute setting.

13. After the desired volume has been set, turn the water supply on.

14. Reinstall the top lid and rear panel.
The brewer may now be returned to service.

OPERATING CONTROLS

A. ON/OFF Switch

ON - Placing the switch in the left position allows the start switch to activate a timed brew cycle for three gallons

of tea.
OFF - Placing the switch in the right position stops the brew cycle. Stopping a brew cycle after it has been started
will not stop the fl ow of water into the funnel until the tank syphons down to its proper level. The switch should

always be placed in this position after a brew cycle and whenever the brewer is unattended.

B. Start Switch
Starts a brew cycle when the ON/OFF switch is in the "ON" position.

C. UNSWEET/OFF/SWEET Selector Switch (Models with Sweetener Only)
UNSWEET - Placing the switch in the left positional allows the start switch to activate a timed brew cycle for
three gallons of tea without sweetener.
OFF - Placing the switch in the middle position stops the brew cycle. Stopping a brew cycle after it has been
started will not stop the fl ow of water into the funnel until the tank syphons down to its proper level. The switch

should always be placed in this position after a brew cycle and whenever the brewer is unattended.
SWEET - Placing the switch in the right positional allows the start switch to activate a timed brew cycle for three

gallons of tea with sweetener.

Page 7

37235 050205

CLEANING

CAUTION - CLEAN AND SANITIZE YOUR ICED TEA BREWER DAILY

1. Remove and thoroughly clean the entire brew funnel. The funnel tip and screen must be free from any tea
particles or residue. Reassemble the funnel.

2. Place the ON/OFF switch in the "OFF" position. Remove and thoroughly rinse the sprayhead. The holes must
be open and clear of any mineral deposits. Wipe the sprayhead panel clean with a damp cloth.

3. Insert the deliming spring into the sprayhead fi tting until no more than two inches is visible and move it in
and out 5 or 6 times. Insert the spring into the airvent hole in the sprayhead panel and move it in and out 5
or 6 times. Reattach the sprayhead.

4. Wash the entire outside surface of the brewer with a clean damp cloth.

CAUTION - DO NOT KEEP BREWED ICED TEA OVERNIGHT. THE SERVER MUST BE CLEANED DAILY.

AUTO SWEETENER CLEANING

1. Remove the connector off of the bag in a box.

2. Place the end in a bucket of hot water (120°-130°F)

3. Place an empty reservoir on the base under the dilution nozzle.

4. Set the selector switch to the "Sweetened" setting.

5. Press and release the "Start" switch.

6. Run three brew cycles in a row, emptying the reservoir after each cycle.

7. When the three cycles have been completed, hook the connector back up to the bag in a box system. (This

will keep buildup from occurring in the system.)

This procedure should be performed weekly or as needed to keep the system clear.

TEA BREWING

1. Begin each brew cycle with a clean empty brew funnel and server. (Be sure the server lid doesn’t interfere
with the fl ow of dilution water.)

2. Insert a BUNN® fi lter into the funnel.

3. Pour the packet of loose fresh tea leaves into the fi lter. Approximately four ounces is recommended.

4. Level the bed of tea leaves by gently shaking.

5. Slide the funnel into the funnel rails until it stops.

6. Place the ON/OFF switch in the "ON" position.

7. Momentarily press the start switch.

CAUTION - The funnel contains hot liquids. Remove funnel slowly.

8. Carefully remove the brew funnel and discard the used fi lter when tea no longer drips from the funnel tip.

9. Place the ON/OFF switch in the "OFF" position to prevent a false start.

10. Fresh tea is available at the faucet.

Page 8

37235 080204

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 qualifi ed service person-

nel.

• 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 fi ttings 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 specifi ed.

• 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

3. Strainer/Flow Control
(.750GPM)

Remedy

Water lines and valves to the brewer
must be open.

Check circuit breakers or fuses.

(A) Direction of fl ow arrow must be
pointing upwards in the brewer.

(B) Remove the strainer/fl ow con­trol and check for obstructions.
Clear or replace.

Page 9

37235 050205

TROUBLESHOOTING (cont.)

PROBLEM

Brew cycle will not start (cont.)

PROBABLE CAUSE

4. ON/OFF Switch

5. Start Switch

6. Brew Timer

7. Brew Solenoid Valve

8. Internal Flow control (.195
GPM)

REMEDY

Refer to Service - ON/OFF Switch
for testing. See page 24

Refer to Service - Start Switch for
testing procedures. See page 23

Refer to Service - Brew Timer for
testing procedures. See page 18

Refer to Service - Brew Solenoid
Valve for testing procedures. See
page 16

(A) Direction of fl ow arrow must be
pointing towards check valve.

(B) Remove the fl ow control and
check for obstructions. Clear or
replace.

Water is not hot

Dilution cycle will not start

1. Limit Thermostat
CAUTION - Do not eliminate or
bypass limit thermostat or thermal
cut-off. Use only BOM replacement
part 29329.0001

2. Control Thermostat

3. Tank Heater

1. ON/OFF Switch

2. Start Switch

Refer to Service - Limit Thermostat
for testing procedures. See page
22

Refer to Service - Control Ther­mostat for testing procedures. See
page 17

Refer to Service - Tank Heater for
testing procedures. See page 27

Refer to Service - ON/OFF Switch
for testing procedures. See page
24

Refer to Service - Start Switch for
testing procedures. See page 23

3. Dilution Timer

Page 10

Refer to Service - Dilution Timer for
testing procedures. See page 21

37235 080204

TROUBLESHOOTING (cont.)
PROBLEM

Dilution cycle will not start (cont.)

Inconsistent beverage level in
dispenser

PROBABLE CAUSE

4. Dilution Solenoid Valve

1. Internal Flow Control (.195
GPM)

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

Refer to Service - Dilution Solenoid
Valve for testing procedures. See
page 20

(A) Direction of fl ow arrow must be
pointing towards the check valve.

(B) Remove the fl ow 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 high or low beverage
level in the dispenser

4. Water Pressure

1. Brew Timer/Delay Timer

2. Strainer/Flow Control
(.750GPM)

The water pressure to the brewer
must be at least 20 psi (138 kPa).

With the ON/OFF switch "ON" adjust
the brew timer to achieve the rec­ommended 76 oz. of concentrate
then the dilution timer to achieve a
total of 396 oz. for each three-gal­lon brew cycle.

(A) Direction of fl ow arrow must be
pointing upwards in the brewer.

(B) Remove the strainer/fl ow con­trol and check for obstructions.
Clear or replace.

Page 11

37235 080204

TROUBLESHOOTING (cont.)
PROBLEM

Spitting or excessive steaming

Drip-out time too long

Dripping from sprayhead

PROBABLE CAUSE

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.

2. Control Thermostat

1. Funnel Tip

1. Syphon System

REMEDY

Inspect tank assembly for excessive
lime deposits. Delime as required.

Refer to Service - Control Ther­mostat for testing procedures. See
page 17

The brew funnel should be cleaned
thoroughly before each brew cycle
to lessen the chance of tea leaf par­ticles clogging the drip-out tip.

The brewer must be level or slightly
lower in front to syphon properly.

Water flows into tank continu­ously (ON/OFF Switch "ON") or
(UNSWEET/OFF/SWEET Switch in
"UNSWEET" or "SWEET" position)

Water flows into tank continu­ously (ON/OFF Switch "OFF") or
(UNSWEET/OFF/SWEET Switch in
"OFF" position)

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. Brew Solenoid Valve

1. Brew Timer

1. Brew Solenoid Valve

Inspect the tank assembly for ex­cessive lime deposits. Delime as
required.

Refer to Service - Brew Solenoid
Valve for testing procedures. See
page 16

Refer to Service - Brew Timer for
testing procedures. See page 18

Refer to Service - Brew Solenoid
Valve for testing procedures. See
page 16

Page 12

37235 050205

TROUBLESHOOTING (cont.)
PROBLEM

Beverage overfl ows dispenser

PROBABLE CAUSE

1. Dispenser

2. Brew Timer

3. Brew Solenoid Valve

4. Dilution Timer

5. Dilution Solenoid Valve

REMEDY

The dispenser must be complete­ly empty before starting a brew
cycle.

Refer to Service - Brew Timer for
testing procedures. See page 18

Remove the Brew Solenoid Valve
and clean any obstruction. Rebuild
or replace the valve if necessary.
See page 16

Refer to Service - Dilution Timer for
testing procedures. See page 21

Refer to Service - Dilution Solenoid
Valve for testing procedures. See
page 20

Weak beverage

1. Filter Type

2. Tea

3. Sprayhead

4. Funnel Loading

5. Water Temperature

®

BUNN

paper fi lters must be used

for proper extraction.

A suffi cient quantity of fresh, loose
tea leaves should be used for
proper extraction.

A clean stainless steel sprayhead
must be used for proper extrac­tion.

The BUNN® paper fi lter must be
centered in the funnel and the bed
of tea leaves 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.

Page 13

37235 080204

TROUBLESHOOTING (cont.)

PROBLEM

Dry tea leaves remain in the fun­nel

Brewer is making unusual noises

PROBABLE CAUSE

1. Funnel Loading

1. Solenoid(s)

2. Plumbing Lines

3. Water Supply

REMEDY

®

The BUNN

paper fi lter must be
centered in the funnel and the bed
of grounds leveled by gently shak­ing.

The nut on the solenoid(s) 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 working pressure to ap­proximately 50 psi (345 kPa).

Sweetener is not working

4. Tank Heater

1. Sweetener box is empty

2. Flow Adjustment screw is
closed

3. Solenoid is defective

4. The Pump is defective

Remove and clean lime off the tank
heater. See page 27

Check the Sweetener box to make
sure it is not out of product.

Check the Flow Adjustment screw
to make sure the valve has not
closed.

Refer to Service -Sweetener Sole­noid Valve for testing procedures.
See page 26

Check the manufacturers warranty
for additional information on test­ing and replacement of a defective
pump.

Page 14

37235 111904

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 qualifi ed
service personnel. The brewer should be disconnected
from the power source when servicing, except when
electrical tests are required and the test procedure
specifi cally 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 and rear inspection panel.

The top cover is attached with one #6-32 screw.
Removal of the top cover will allow access to ON/OFF
switch, start switch, brew timer, dilution timer, control
thermostat, limit thermostat and tank heater,

The rear inspection panel is attached with six #8-32
screws. Removal of the rear panel will allow access to
the brew solenoid valve, dilution solenoid valve and
the sweetener solenoid valve (optional), .195 GPM &
.750 GPM fl ow control and check valves.

Contents

Brew Solenoid Valve ............................................16

Control Thermostat ..............................................17

Digital Brew Timer................................................18

Dilution Timer ......................................................20

Dilution Solenoid Valve ........................................21

Limit Thermostat ..................................................22

Start Switch ....................................................... 23

ON/OFF Switch .....................................................24

UNSWEET/OFF/SWEET Switch .............................25

Sweetner Solenoid ...............................................26

Tank Heater ......................................................... 27

Wiring Diagrams ................................................. 28

FIG. 1 COMPONENT ACCESS

P3034

Page 15

37235 050205

SERVICE (cont.)

4

2

3

1

MM

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35

5

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5

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6

7

8

BREW SOLENOID VALVE

If continuity is not present as described, replace the
solenoid valve.

L
E

D

6. Check the solenoid valve for coil action. Connect
the brewer to the power source. 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.

7. 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, replace the
solenoid valve.

FIG. 2 BREW SOLENOID VALVE

P3040

Location:
Viewing the brewer from the rear the brew sole­noid valve is mounted on the left side of the mounting
bracket.

Test Procedures:

1. Disconnect the brewer from the power source.

2. Disconnect the white/violet and white/green wires
from the solenoid valve. With the ON/OFF switch
in the "ON" upper position press the start switch.

3. With a voltmeter, check the voltage across the
white/violet and white/green wires. Connect the
brewer to the power source. The indication must
be:

a) 120 volts ac for two wire 120 volt models.
b) 230 volts ac for two wire 230 volt models.
c) 100 volts ac for two wire 100 volt models.

4. Disconnect the brewer from the power source,

Removal and Replacement:

1. Remove all wires from solenoid valves.

2. Turn off the water supply to the brewer.

3. Disconnect the water lines to and from the sole­noid valves.

4. Remove the two #8-32 keps nuts holding the
mounting bracket to the brewer base.

5. Lift out the bracket.

6. Remove the two #10-32 slotted-head screws hold­ing the solenoid valve to the mounting bracket.

7. Securely install the new solenoid valve to the
mounting bracket.

8. Attach the mounting bracket to the brewer base.

9. Securely fasten the water lines to and from the
solenoid valves.

10. Refer to the Fig.3 when reconnecting the wires

WHI/VIO to Dilution
Solenoid

WHI/GRN to
Brew Timer TL4

WHI/VIO to Brew Solenoid
WHI/VIO to Brew Timer TL1

If voltage is present as described, proceed to #5
If voltage is not present as described, refer to Wiring
Diagrams and check brewer wiring harness.

5. Check for continuity across the solenoid valve coil
terminals.

If continuity is present as described, reconnect the
white/violet from the ON/OFF switch and white/green
wire from the brew timer.

Page 16

WHI/BLU to Dilution
Timer TL4

BREW
SOLENOID

DILUTION
SOLENOID

FIG.3 SOLENOID VALVE TERMINALS

P1278

37235 080204

SERVICE (cont.)

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35

5

CONTROL THERMOSTAT

thermostat is turned fully clockwise. Connect the
brewer to the power source. The indication must

be:
a) 120 volts ac for two wire 120 volt models.
b) 230 volts ac for two wire 230 volt models.
c) 100 volts ac for two wire 100 volt models.

8. Disconnect the brewer from the power source.

C

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5

6

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­5

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TE

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MI

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MI

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A

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P3040

FIG. 4 CONTROL THERMOSTAT

Location:

The control thermostat is located inside hood on

the right side just behind the dilution timer.

Test Procedures:

1. Disconnect the brewer from the power source.

2. Locate the blue/black wire on the control thermo­stat.

3. With a voltmeter, check the voltage across the
blue/black wire on the control thermostat and
the white wire on the tank heater for 100 volt and
120 volt two wire models or red wire on the tank
heater for 230 volt two wire models. Connect the
brewer to the power source. The indication must
be:

a) 120 volts ac for two wire 120 volt models.
b) 230 volts ac for two wire 230 volt models.
c) 100 volts ac for two wire 100 volt models.

4. 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. Remove both wires from the control thermostat
terminals.

2. Remove the thermostat capillary bulb by fi rmly
pulling up on the capillary tube at the tank lid. This
will disengage the grommet from the tank lid.

3. Remove the #8-32 screw holding the control
thermostat to its bracket.

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 fi rmly and evenly
so that the groove in the grommet fi ts into the tank
lid.

6. Carefully bend the capillary tube so that the tube
and bulb inside the tank are in a vertical posi­tion.

NOTE – The capillary tube must be clear of any electri­cal termination and not kinked.

7. Fasten the new control thermostat to its bracket.

8. Refer to Fig. 5 when reconnecting the wires.

9. Adjust the control thermostat as required.

If voltage is present as described, proceed to #5.
If voltage is not present as described, refer to the Wir-
ing 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. With a voltmeter, check the voltage across the
black wire of the control thermostat and the white
wire on the tank heater for 100 volt and 120 volt
two wire models or red wire on the tank heater
for 230 volt two wire models when the control

Page 17

BLK to Tank
Heater

BLU/BLK to Limit Ther­mostat

P1280

FIG. 5 CONTROL THERMOSTAT TERMINALS

37235 080204

SERVICE (cont.)

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5

DIGITAL BREW TIMER

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P3040

FIG. 6 DIGITAL BREW TIMER

Location:
The timer is located in the hood, on the left side.

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 front access panel.

2. Remove the two #8-32 screws securing circuit
board to the mounting bracket.

3. Remove circuit board and spacers (as required).

4. With a voltmeter, check the voltage across terminals
TL1 and TL2 when the "ON/OFF" switch is in the
"ON" position. Connect the brewer to the power
source. The indication must be:

a) 120 volts ac for two wire 120 volt models.
b) 230 volts ac for two wire 230 volt models.
c) 100 volts ac for two wire 100 volt models.

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.

If voltage is not as described, disconnect the brewer
from the power source and replace the timer.

7. With a voltmeter, check the voltage across ter­minals TL1 and TL4 when the "ON/OFF" switch
is in the "ON" position. Connect the brewer to the
power source and press the "START" switch. The
indication must be as follows:

a) 120 volts ac for two wire 120 volt models.
b) 230 volts ac for two wire 230 volt models.
c) 100 volts ac for two wire 100 volt models.

If voltage is present as described, the brew timer is
operating properly. Reset the timer as required, to
obtain the desired brew volume.
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 #8-32 screws securing circuit
board to the hood.

2. Remove circuit board and spacers (as required).

3. Remove all wires from the timer.

4. Attach all wires to the replacement timer board
prior to installation to the component mounting
bracket. Refer to FIG. 7 when reconnecting the
wires.

5. Install new circuit board with spacers (as required)
to the component mounting bracket.

6. Adjust the timer as described below.

Timer Setting:
NOTE: Prior to setting or modifying volumes, check
that the brewer is connected to water supply, the
tank is properly fi lled, and a funnel and server are in
place.
NOTE: All volume settings must be done with the
sprayhead installed.

6. With a voltmeter, check the voltage across terminals
TL1 and TL4 when the "ON/OFF" switch is in the
"ON" position. Connect the brewer to the power
source. The indication must be 0 volts.

If voltage is as described, proceed to #7.

Page 18

1. Modifying brew volumes. To modify a brew vol­ume, fi rst check that the SET/LOCK switch is in the
"SET" position on the circuit board.

37235 080204

SERVICE (cont.)
DIGITAL BREW TIMER (cont.)

To increase a brew volume, place the ON/OFF
switch in the "ON" position, press and hold the START
switch until three clicks are heard. Release the switch
and press it again one or more times. (Failure to re­lease the switch within two seconds after the third click
causes the volume setting to be aborted and previous
volume setting will remain in memory.) Each time the
switch is pressed, two seconds are added to the brew
time period. Allow the brew cycle to fi nish in order to
verify that the desired volume has been achieved.

To decrease a brew volume, place the ON/OFF
switch in the "ON" position, press and release the
START switch once for every two-second interval to
be removed from the total brew time period; then im­mediately press and hold down the START switch until
three clicks are heard. Release the switch. (Failure to
release the switch within two seconds after the third
click causes the volume setting to be aborted and
previous volume setting will remain in memory). Al­low the brew cycle to fi nish in order to verify that the
desired volume has been achieved.

3. Setting programming disable feature. If it be-
comes necessary to prevent anyone from changing
brew time once programmed, you can set the SET/
LOCK switch to the "LOCK" position. This will prevent
any further programming until switch is once again
put into the "SET" position.

2. Setting brew volumes. To set a brew volume,
fi rst check that the SET/LOCK switch is in the "SET"
position on the circuit board. Place the ON/OFF switch
in the "ON" position, press and hold the START switch
until three distinct clicks are heard and then release
the switch. (Failure to release the switch within two
seconds after the third click causes the volume setting
to be aborted and previous volume setting will remain
in memory.)
View the level of the liquid being dispensed. When
the desired level is reached, turn the ON/OFF switch
to "OFF".
NOTE: Several ounces of water will continue to sy­phon from the tank after turning the switch "OFF".
The brewer remembers this volume and will continue
to brew batches of this size until the volume setting
procedure is repeated.
NOTE: When brewing tea, volume will decrease due
to absorption by the tea grounds.

TL1 - WHI/VIO to Dilution Timer and
WHI/VIO to ON/OFF Switch
TL2 - WHI to Power Cord (100V & 120V) or
RED to Power connector (230V) and
WHI to Dilution Timer (100V & 120V) or
RED to Dilution Timer (230V)
TL3 - WHI/ORN to Start Switch
TL4 - WHI/GRN to Brew Solenoid
TL5 - WHI/YEL to Start Switch

P2037

FIG. 7 DIGITAL TIMER WIRING

Page 19

37235 080204

SERVICE (cont.)

4

2

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8

DILUTION SOLENOID VALVE

P3040

FIG. 8 DILUTION SOLENOID VALVE

Location:
Viewing the brewer from the rear the dilution sole­noid is mounted on the center of the solenoid mount­ing bracket which is secured to the trunk base.

Test Procedure:

1. Disconnect the brewer from the power source.

2. With a voltmeter, check the voltage across the
white/blue and white/violet wires on the dilution
solenoid terminals when the ON/OFF switch is in
the “ON” position and the start switch is momen­tarily placed in the lower position. Connect the
brewer to the power source. After the approximate
setting on the delay dial, the indication must be:

a) 120 volts ac for two wire 120 volt models.
b) 230 volts ac for two wire 230 volt models.
c) 100 volts ac for two wire 100 volt models, re-

main for the approximate setting on the dilution
dial, and then return to its previous indication.

3. Disconnect the brewer from the power supply.

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. Remove both wires from the coil and check for
continuity across the coil terminals.

If continuity is present as described, reconnect the
white/blue and white/violet wires and proceed to #5.
If continuity is not present as described, replace the
solenoid valve.

5. Check the solenoid valve for coil action. Connect

Page 20

the brewer to the power source, place the ON/OFF
switch in the “ON” position and momentarily place
the start switch in the lower position and release.
Listen carefully after the approximate setting on
the delay dial in the vicinity of the solenoid valve
for a “clicking” sound as the coil magnet attracts
and after the approximate setting on the dilution
dial, repels the plunger.

6. 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 or after 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, replace the
solenoid valve.

Removal and Replacement:

1. Remove all wires from the solenoid valves.

2. Turn off the water supply to the brewer.

3. Disconnect the water lines to and from the sole­noid valves.

4. Remove the two 8-32 keps nuts holding the
mounting bracket to the trunk base.

5. Lift out the bracket.

6. Remove the two 10-32 slotted-head screws hold­ing the solenoid valve to the mounting bracket.

7. Securely install the new solenoid valve to the
mounting bracket.

8. Attach the mounting bracket to the trunk base.

9. Securely fasten the water lines to and from the
solenoid valves.

10. Refer to Fig. 9 when reconnecting the wires.

WHI/VIO to Dilution
Solenoid

BREW
SOLENOID

FIG. 9 SOLENOID VALVE TERMINALS

WHI/GRN to
Brew Timer TL4

DILUTION
SOLENOID

WHI/VIO to Brew Solenoid
WHI/VIO to Brew Timer TL1

WHI/BLU to Dilution
Timer TL4

P1278

37235 080204

SERVICE (cont.)

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35

5

DILUTION TIMER

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FIG. 10 DILUTION TIMER

P3040

Location:
The dilution timer is located inside the hood on the
right side. It consists of the dial plate with two dials
and circuit board.

Test Procedure:

1. Disconnect the brewer from the power source and
remove the wires from terminals TL3, TL4, & TL5
of the timer and rotate both dials fully counter­clockwise.

2. With a voltmeter, check the voltage across termi­nals TL1 and TL2 when the ON/OFF switch is in the
"ON" position. Connect the brewer to the power
source. The indication must be:

a) 120 volts ac for two wire 120 volt models.
b) 230 volts ac for two wire 230 volt models.
c) 100 volts ac for two wire 100 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.

If continuity is present as described, reconnect the
wires to terminals TL3, TL4, & TL5 of the timer board
and proceed to #5.
If continuity is not present as described, refer to the
Wiring Diagrams and check the wiring harness.

5. With a voltmeter, check the voltage across termi­nals TL1 and TL4 when the ON/OFF switch is in the
"ON" position and the start switch is momentarily
placed in the lower position. Connect the brewer to
the power source. After a delay of approximately
three minutes, the indication must be:

a) 120 volts ac for two wire 120 volt models for

approximately one minute and then return to its
previous indication.

b) 230 volts ac for two wire 230 volt models for

approximately one minute and then return to its
previous indication.

c) 100 volts ac for two wire 100 volt models for

approximately one minute and then return to its
previous indication.

6. Disconnect the brewer from the power source.

If voltage is present as described, the timer is operat­ing properly. Adjust the timer dials as required.
If voltage is not present as described, replace the
timer.

Removal and Replacement:

1. Remove all wires from the timer.

2. Remove the circuit board and dial plate from the
brackets.

4. Install the new dial plate and circuit board to the
brackets.

5. Refer to Fig. 11 when reconnecting the wires.

6. Adjust the timer dials as required.

WHI/BLU to Dilution Solenoid

RED/BLK to Start Switch

WHI to Brew Timer (100V &
120V Models)
RED to Brew Timer (230V
Models)

WHI/VIO to ON/OFF Switch

GRN to Start Switch

4. Check for continuity across the green and red/
black wires when the start switch is held in the
lower position.

Page 21

FIG. 11 DILUTION TIMER TERMINALS

P1281

37235 080204

SERVICE (cont.)

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5

LIMIT THERMOSTAT

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FIG. 12 LIMIT THERMOSTAT

P3040

Location:
The limit thermostat is located inside the hood on
the tank lid.

5. With a voltmeter, check the voltage across the
exposed terminal of the limit thermostat and the
white wire from the power cord or the red wire
from the power connector. Connect the brewer to
the power source. The indication must be:

a) 120 volts ac for two wire 120 volt models.
b) 230 volts ac for two wire 230 volt models.
c) 100 volts ac for two wire 100 volt models.

6. Disconnect the brewer from the power source.

If voltage is present as described, reconnect the blue/
black wire to the limit thermostat. The limit thermostat
is operating properly.
If voltage is not present as described, replace the limit
thermostat.

Removal and Replacement

1. Remove both wires from the limit thermostat
terminals.

2. Carefully slide the limit thermostat out from under
the retaining clip.

3. Carefully slide the new limit thermostat into the
retaining clip.

4. Refer to Fig. 13 when reconnecting the wires.

Test Procedure:

1. Disconnect the brewer from the power source and
remove the black wire from the limit thermostat.

2. With a voltmeter, check the voltage across the
black wire removed from the limit thermostat
and the white wire or red wire on the tank heater
terminal. Connect the brewer to the power source.
The indication must be:

a) 120 volts ac for two wire 120 volt models.
b) 230 volts ac for two wire 230 volt models.
c) 100 volts ac for two wire 100 volt models.

3. Disconnect the brewer from the power source.

If voltage is present as described, reconnect the black
wire and proceed to #4.
If voltage is not present as described, refer to the Wir-
ing Diagrams and check the wiring harness.

4. Remove the blue/black wire from the limit ther­mostat.

BLU/BLK to
Control
Thermostat

BLK to Power Cord or
Power Connector

P1800

FIG. 13 LIMIT THERMOSTAT TERMINALS

Page 22

37235 050205

SERVICE (cont.)
START SWITCH

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 present as described, reconnect the
wires, the switch is operating properly.
If continuity is not present as described, replace the
switch.

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. 15 when reconnecting the wires.

GRN to Dilution
Timer TL5

WHI/YEL to Brew
Timer TL5

FIG. 14 START SWITCH

P3034

Location:

The start switch is located in the front of the hood,

above and to the right of the brew funnel.

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.

If continuity is present as described, proceed to #4.
If continuity is not present as described, replace the
switch.

RED/BLK to Dilu­tion Timer TL3

FIG. 15 START SWITCH TERMINALS

WHI/ORN to
Brew Timer TL3

P1283

Page 23

37235 080204

SERVICE (cont.)

ON/OFF SWITCH

If voltage is present as described, proceed to #6.
If voltage is not present as described, refer to the Wir-
ing Diagrams and check the wiring harness.

6. Check for continuity across the center and end
terminals of the top row when the switch is in the
“ON” position.

If continuity is present as described, replace the wires,
the switch is operating properly.
If continuity is not present as described, replace the
switch.

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. 17 when reconnecting the wires.

FIG. 16 ON/OFF SWITCH

P3034

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 Option

1. Disconnect the brewer from the power source.

2. Remove the black and white/violet wires from the
switch terminals.

3. With a voltmeter, check the voltage across the
black wire removed from the ON/OFF switch and
the white wire remaining on the switch terminal.

4. Connect the brewer to the power source. The
indication must be:

a) 120 volts ac for two wire 120 volt models.
b) 230 volts ac for two wire 230 volt models.
c) 100 volts ac for two wire 100 volt models.

5. Disconnect the brewer from the power source.

BLK to Power Cord (100V &

WHI/VIO to Dilution
Timer

WHI/VIO

WHI/VIO to Brew
Timer TL1

120V Models
BLK to Power Connector
(230V Models)

FIG.17 ON/OFF SWITCH TERMINALS

WHI to Dilution Timer TL2
(100V & 120V Models)
RED to Dilution Timer (230V
Models)

P1282

Page 24

37235 050205

SERVICE (cont.)

UNSWEET/OFF/SWEET SWITCH (Sweetner Option)

5. Disconnect the black and white wires from the
center terminals.

6. Disconnect the brown/white and white/violet wires
from the right side terminals.

7. Check for continuity across the center and right
terminals in rows one through four when the
switch is in the "SWEET” position.

If continuity is present as described, replace the wires
on the right side and proceed to #8.
If continuity is not present as described, replace the
switch.

8. Disconnect the white/violet wires on the left side
terminal.

9. Check for continuity across the center and left
side terminals in rows one through four when the
switch is in the "UNSWEET” position.

P3034

FIG. 18 UNSWEET/OFF/SWEET SWITCH

Location:

The UNSWEET/OFF/SWEET switch is located in
the front of the hood, above and to the left of the
brew funnel.

Test Procedure:

1. Disconnect the brewer from the power source.

2. With a voltmeter, check the voltage across the

black wire and white wire on the selector switch.

3. Connect the brewer to the power source. The

indication must be:
a) 120 volts ac for two wire 120 volt models.
b) 230 volts ac for two wire 230 volt models.
c) 100 volts ac for two wire 100 volt models.

4. Disconnect the brewer from the power source.

If continuity is present as described, replace the wires
the switch is operating properly.
If continuity is not present as described, replace the
switch.

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. 19 when reconnecting the wires.

WHT/GRN to
Brew Sol

WHT/VIO
to Brew
Timer TL1

BLK to Power Cord

BRN/WHI to
Sweetener Sol

WHT to Power Cord

If voltage is present as described, proceed to #5.
If voltage is not present as described, refer to the Wir-
ing Diagrams and check the wiring harness.

Page 25

P1763

FIG.19 UNSWEET/OFF/SWEET

SWITCH TERMINALS

37235 050205

SERVICE (cont.)
SWEETNER SOLENOID VALVE

P3298

FIG. 20 SWEETNER SOLENOID VALVE

Location:
Viewing the brewer from the front, the sweetener
solenoid is mounted on the right side of the solenoid
mounting bracket which is secured to the bottom base
housing.

If continuity is not present as described, replace the
solenoid valve.

5. Check the solenoid valve for coil action. Con­nect the brewer to the power source, place the
UNSWEET/OFF/SWEET switch in the “SWEET”
position and momentarily place the start switch
in the lower position and release. At the start of
a brew cycle, listen carefully in the vicinity of the
solenoid valve for a “clicking” sound as the coil
magnet attracts and at the end of the brew cycle
when the plunger is released.

6. Disconnect the brewer from the power source.

If the sound is heard as described and sweetener
will not pass through the solenoid valve, there may
be a blockage in the sweetener line before or after
the solenoid valve or, the solenoid valve may require
inspection for wear, and removal of particles.
If the sound is not heard as described, replace the
solenoid valve.

Test Procedure:

1. Disconnect the brewer from the power source.

2. With a voltmeter, check the voltage across the
brown/white and white/violet wires on the sweet­ener solenoid terminals when the UNSWEET/OFF/
SWEET switch is in the “SWEET” position and the
start switch is momentarily placed in the lower
position. Connect the brewer to the power source.
After the approximate setting on the delay dial, the
indication must be:

a) 120 volts ac for two wire 120 volt models.
b) 230 volts ac for two wire 230 volt models.
c) 100 volts ac for two wire 100 volt models,
remain for the approximate setting on the dilution

dial, and then return to its previous indication.

3. Disconnect the brewer from the power supply.

If voltage is present as described, proceed to #4.
If voltage is not present as described, refer to the Wir­ing Diagrams and check the wiring harness.

Removal and Replacement:

1. Remove all wires from the solenoid valves.

2. Turn off the sweetener supply to the brewer.

3. Disconnect the water lines to and from the sole­noid valves.

4. Remove the two #8-32 keps nuts holding the
solenoid bracket to the mounting bracket.

5. Lift out the valve and bracket.

6. Remove the two #10-32 slotted-head screws hold­ing the solenoid valve to the mounting bracket.

7. Securely install the new solenoid valve to the
mounting bracket.

8. Attach the solenoid valve and bracket to the
mounting bracket.

9. Securely fasten the sweetener and water lines to
and from the solenoid valves.

10. Refer to Fig. 19 when reconnecting the wires.

WHI/VIO to Brew Solenoid
WHI/VIO to Brew Timer TL1

4. Remove both wires from the coil and check for
continuity across the coil terminals. If continuity
is present as described, reconnect the brown/white
and white/violet wires and proceed to #5.

Page 26

BRN/WHI to Selector
Switch

P2843

FIG. 21 SOLENOID VALVE TERMINALS

37235 050205

SERVICE (cont.)

M

I

N

U

T

E

S

M

I

N

U

T

E

S

D

E

L

A

Y

DI

L

U

T

I

O

N

B

U

N

N

-

O

-

M

A

T

IC

P

/

N

3

35

5

TANK HEATER

IC
T
A

M

-

5

6

O

-

N

4

3355

N

7

U

N

B

P/

3

8

6

7

2

5

S
E

1

6

T
U

4

IN

M

ON
I
T

3

S

ILU

E

D

T
U
N

I
M

Y

A
EL
D

P3040

FIG. 22 TANK HEATER

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. With a voltmeter, check the voltage across the
black and white wires on 100 volt and 120 volt
models or the black and red wires for 230 volt
models. Connect the brew to the power source.
The indication must be:

a) 120 volts ac for two wire 120 volt models .
b) 230 volts ac for two wire 230 volt models.

c) 100 volts ac for two wire 100 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 wiring harness.

NOTE- If the tank heater remains unable to heat,

remove and inspect heater for cracks in the
sheath.

Removal and Replacement:

1. Disconnect the black wire and the white or red
wire from the tank heater terminals.

2. Remove sprayhead and the hex nut securing the
sprayhead tube to the hood. Set aside for reas­sembly.

3. Disconnect vent tube.

4. Remove the six #10 thread cutting screws securing
the tank lid to the tank.

5. Remove the tank lid with limit thermostat, spray­head tube, tank heater and vent tube.

6. Remove the two hex nuts securing the tank heater
to the tank lid. Remove tank heater with gaskets
and discard.

7. Install new tank heater with gaskets on the tank
lid and secure with two hex nuts.

8. Install tank lid with limit thermostat, sprayhead
tube, tank heater and vent tube using six #10
thread cutting screws.

9. Secure sprayhead tube to hood using a hex nut.

10. Install sprayhead.

11. Connect vent tube to fi tting.

12. Reconnect the wires to the limit thermostat, tank
heater. See limit thermostat section in this manual
when reconnecting wires.

13. Refer to Fig. 23 when reconnecting the tank heater
wires.

WHI to Power Cord (100V

BLK to Control
Thermostat

& 120V Models)
RED to Power Connector
(230V Models)

4. Disconnect the black wire and the white wire or
red wire from the tank heater terminals.

5. Check for continuity across the tank heater termi­nals.

If continuity is present as described, reconnect the
wires, the tank heater is operating properly.
If continuity is not present as described, replace the
tank heater.

Page 27

FIG. 23 TANK HEATER TERMINALS

P1284

37235 080204

SCHEMATIC WIRING DIAGRAM TB3, TB3B, TB3-LP

OPTIONAL

READY

INDICATOR

BLU

L1 N

LIMIT

THERMOSTAT

BLU/BLK

ON/OFF SWITCH

BLK

SWITCH &

THERMOSTAT

BLK

BLK BLK

"KEEP WARM" HEATER

GRN

WHI

TANK HEATER

WHI WHI

WHI

BREW
TIMER

DILUTION

TIMER

5 4 3 2 1 5 4 3 2 1

WHI/VIO WHI/VIO

WHI/VIO

WHI/VIO WHI/GRN

DILUTION

SOL

1

BREW

SOL

2

WHI

WHI/BLU

WHI/ORN

WHI/YEL

START

SWITCH

RED/BLK

GRN

100 VOLTS AC
120 VOLTS AC

2 WIRE

SINGLE PHASE

37234.0000C 05/06 © 2004 BUNN-O-MATIC CORPORATION

WHI

Page 28

37235 053006

SCHEMATIC WIRING DIAGRAM

TU3, TB3 W/SWEETENER

READY INDICATOR

BLU/BLK

SELECTOR SWITCH

UNSWEET/OFF/SWEET

BLK

120 VOLTS AC

2 WIRE

SINGLE PHASE

WHI/VIO

WHI WHI

WHI/BLU

BRN/WHI
WHI/ORN

WHI/YEL

27432.0000E 08/04 © 1996 BUNN-O-MATIC CORPORATION

WHI/BLU

Page 29

37235 050205

SCHEMATIC WIRING DIAGRAM TB3A

OPTIONAL

READY

INDICATOR

BLU

L1 N

LIMIT

THERMOSTAT

BLU/BLK

ON/OFF SWITCH

BLK

SWITCH &

THERMOSTAT

BLK

THERMAL

FUSE

BLKBLK

"KEEP WARM" HEATER

GRN/YEL

THERMAL

FUSE

RED

TANK HEATER

WHIWHI

RED

BREW
TIMER

WHI/VIO WHI/VIO

WHI/VIO

WHI/VIO WHI/GRN

SOL

1

BREW

DILUTION

SOL

2

RED

WHI/BLU

WHI/ORN

WHI/YEL

230 VOLTS AC

2 WIRE

SINGLE PHASE

37234.0005A 05/05 © 2005 BUNN-O-MATIC CORPORATION

DILUTION

TIMER

5 4 3 2 15 4 3 2 1

RED

START

SWITCH

RED/BLK

GRN

Page 30

37235 050205

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37235 050205