Bunn Coffee Maker C, CT, CTF, CWT, CWTF Service Manual

CAUTION :

CAUTIO

N

!

C, CT, CTF,
CWT, CWTF,
SINGLE CW,

SINGLE CWF

OPERATING & SERVICE MANUAL

BUNN-O-MATIC CORPORATION

POST OFFICE BOX 3227

SPRINGFIELD, ILLINOIS 62708-3227

PHONE: [phone] FAX: [phone]

To ensure you have the latest revision of the Operating Manual, or to view the Illustrated Parts
Catalog, Programming Manual, or Service Manual, please visit the Bunn-O-Matic website, at
www.bunn.com. This is absolutely FREE, and the quickest way to obtain the latest catalog and

manual updates. For Technical Service, contact Bunn-O-Matic Corporation at 1-800-286-6070.

10841.0000G 10/08 ©1996 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 [phone] 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, BrewWIZARD, BUNN Gourmet Ice, BUNN Pour-O-Matic, BUNN, Bunn-OMatic, Bunn-O-Matic,
BUNNlink, BUNNserve, BUNN Espress, DBC, Dr. Brew, Dual, EasyClear, EasyGard, Easy Pour, FlavorGard, Gourmet Ice,
Gourmet Juice, High Intensity, IMIX, Infusion Series, Legendary for Quality, Quality Beverage Equipment Worldwide, The
Mark of Quality in Beverage Equipment Worldwide, My Café, PowerLogic, Safety-Fresh, Scale-Pro, Single, Smart Funnel,
Smart Hopper, SmartWAVE, Soft Heat, SplashGard, System III, ThermoFresh, 392, AutoPOD, AXIOM, Beverage Profit
Calculator, Beverage Bar Creator, BrewMETER, BUNNSERVE, BUNNsource, Coffee At Its Best, Cool Froth, Digital Brewer
Control, Intellisteam, Nothing Brews Like a BUNN, Pouring Profits, Pulse Wave, Signature Series, Silver 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

10841 073108

USER NOTICES

CAUTION

POUR IN WATER ONLY

WARMERS AND SURFACES ARE HOT

This equipment must be installed to comply
with the International Plumbing Code of the
International Code Council and the Food
Code Manual of the Food and Drug Adminis­tration (FDA). For models installed outside
the U.S.A., comply with the applicable
Plumbing /Sanitation Code.

Carefully read and follow all notices in this manual and on the equipment. All labels on the equipment should
be kept in good condition. Replace any unreadable or damaged labels.

#00656.0000

#00831.0000

#00658.0000

#02763.0000

#12364.0000

#37881.0000

Page 3

10841 101008

L2 RED

L1 BLACK

ELECTRICAL REQUIREMENTS

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.

Refer to Data Plate on the Brewer, and local/national electrical codes to determine circuit requirements.

Model 15 has an attached cordset and requires 2-wire grounded service rated 120 volts ac, 15 amp,

single phase, 60 Hz.

Model 20 requires 2-wire,

grounded service rated 120 volts
ac, 20 amp, single phase, 60 Hz.
Proceed as follows:

Model 35 requires 3-wire,

grounded service rated 120/208
or 120/240 volts ac, 20 amp,
single phase, 60 Hz. Proceed as
follows:

“A" & "B” models require

2-wire, grounded service rated 200
volts ac or 230 volts ac, 20 amp,
single phase, 50 Hz. Proceed as
follows:

Electrical Hook-Up
CAUTION – Improper electrical installation will damage electronic components.

1. An electrician must provide electrical service as specified.

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

3. Place the heater switch at the rear of the brewer in the “OFF” lower position.

4. Remove the front panel beneath the sprayhead.

5. Feed the cord through the strain relief and connect it to the terminal block.

6. Connect the brewer to the power source and verify the voltage at the terminal block before proceeding.
Replace the front panel.

7. 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.

CE REQUIREMENTS

• This appliance must be installed in locations where it can be overseen by trained personnel.

• For proper operation, this appliance must be installed where the temperature is between 0°C to 35°C.

• Appliance shall not be tilted more than 10° for safe operation.

• An electrician must provide electrical service as specied in conformance with all local and national codes.

• This appliance must not be cleaned by water jet.

• This appliance is not intended for use by persons (including children) with reduced physical, sensory or mental

capabilities, or lack of experience and knowledge, unless they have been given instructions concerning use of
this appliance by a person responsible for its safety.

• If the power cord is ever damaged, it must be replaced by the manufacturer or authorized service personnel with

a special cord available from the manufacturer or its authorized service personnel in order to avoid a hazard.

Page 4

10841 101008

PLUMBING REQUIREMENTS

Model C:

This model is completely portable and requires no attached plumbing.

Models CT, CTF, CWT, CWTA, CWTB, CWTF, CWTFA & CWTFB, SINGLE CW & SINGLE CWF

These brewers must be connected to a cold water system with operating pressure between 20 and 90 psi
(138 to 620kPa) 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 (620kPa)to reduce it to 50 psi (345kPa). The
water inlet fitting is 1⁄4" flare.

NOTE - Bunn-O-Matic recommends 1⁄4" copper tubing for installations of less than 25 feet and 3⁄8" for more than 25
feet from the 1⁄2" water supply line. 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 flow.

This equipment must be installed to comply with the International Plumbing Code of the
International Code Council and the Food Code 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.

MODELS W/OUT FAUCET

MODELS W/FAUCET

Models CT, CWT, CTF, CWTF, SINGLE CW & SINGLE CWF

1. Flush the water line and securely attach it to the flare fitting on the strainer or tee.

2. Turn on the water supply.

3. On CTF, CWTF and SINGLE CWF Models, place an empty vessel beneath the faucet and lift the handle until

water is dispensed.

Page 5

10841 101008

INITIAL SET-UP

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

when specified in the instructions.

1. Insert an empty funnel into the funnel rails.

2. Place an empty dispenser under the funnel.

3. Place the heater switch at the rear of the brewer in the “OFF” lower position and connect the brewer to the
power source.

4. Fill the tank with water as directed:

4A. Model C

Pour three pitchers of tap water into the screened area on top of the brewer. Allow approximately two

minutes between pitchers for water to flow into the tank. While the third pitcher of water is entering the
tank, the tank will fill to capacity and the excess will flow from the sprayhead, out of the funnel, and into the
dispenser.

4B. Models CT, CTF, CWT, CWTA, CWTB, CWTF, CWTFA, CWTFB, SINGLE CW & SINGLE CWF

Connect the brewer to the power source, place the "ON/OFF" switch in the "ON" upper position, and momen-

tarily press and release the start switch. Water will begin flowing into the tank. When water stops flowing
into the tank, initiate a second and a third brew cycle. During the third brew cycle the tank will fill to its
capacity and the excess will flow from the sprayhead, out of the funnel, and into the dispenser.

5. When the flow of water from the funnel stops, place the heater switch at the rear of the brewer in the “ON”
upper position and wait approximately twenty minutes for the water in the tank to heat to the proper tem­perature. Some water will drip from the funnel during this time; this is due to expansion and should not
occur thereafter.

6. Empty the dispenser and initiate another brew cycle as directed:

6A. Model C

Pour one pitcher of tap water into the screened area on top of the brewer.

6B. Models CT, CTF, CWT, CWTA, CWTB, CWTF, CWTFA, CWTFB, SINGLE CW & SINGLE CWF

Place the "ON/OFF" switch in the "ON" upper position, and on models SINGLE CW and SINGLE CWF place

the batch selector switch in the "1 GAL" position. Momentarily press and release the start switch.

7. Place the "ON/OFF" switch in the lower “OFF” position after water has stopped flowing from the funnel, and
let the water in the tank reheat to the proper temperature.

8. Empty the dispenser; place the "ON/OFF" switch in the "ON" upper position, and momentarily press and release
the start switch. Check the water volume in the dispenser after water has stopped flowing from the funnel.
It should be 64 ounces for all models except SINGLE CW and SINGLE CWF should be 128 ounces.

9. Models SINGLE CW and SINGLE CWF only, place the batch selector switch in the "1/2 GAL" position, and
momentarily press and release the start switch. Check the water volume in the dispenser after water has
stopped flowing from the funnel. It should be 64 ounces.

10. If water volumes are not correct, adjust the brew timer as required. See Adjusting Brew Volumes. Allow
the water to reheat, start, and measure another brew cycle.

11. Repeat step 10 until correct water volume is achieved.

The brewer is now ready for use in accordance with the coffee brewing instructions on the next page.

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 filled, and a funnel and server are in place.

1. Modifying batch sizes. To modify a batch volume, first check that the SET/LOCK switch is in the “SET” posi-

Page 6

10841 020503

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 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. (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 finish in order to verify that the desired volume has been achieved.

OPERATING CONTROLS

Model C
ON/OFF SWITCH

Placing the "ON/OFF" switch in the "ON" upper position supplies power to the brew station warmer.

Models CT, CTF, CWT, CWTA, CWTB, CWTF, CWTFA, CWTFB, SINGLE CW & SINGLE CWF
ON/OFF SWITCH

Placing the "ON/OFF" switch in the "OFF" lower position stops brewing. Stopping a brew cycle after it has been
started will not stop the flow of water into the funnel until the tank syphons down to its proper level. Placing the
switch in the "ON" upper position supplies power to the brew station warmer and enables the brew circuit.

START SWITCH

Momentarily pressing and releasing the switch starts a brew cycle when the "ON/OFF" switch is in the "ON"
upper position.

NOTE – The "ON/OFF" switch must be in the "ON" upper position to initiate and complete a brew cycle.

COFFEE BREWING

1. Insert a BUNN® filter into the funnel.

2. Pour the fresh coffee into the filter and level the bed of grounds by gently shaking.

3. Slide the funnel into the funnel rails.

4. Place an empty dispenser beneath the funnel.

5. Operate the brewer as directed:

5A. Model C

Pour one pitcher of tap water into the screened area on top of the brewer.

5B. Models CT, CTF, CWT, CWTA, CWTB, CWTF, CWTFA, CWTFB, SINGLE CW & SINGLE CWF

Place the "ON/OFF" switch in the "ON" upper position. Momentarily press and release the start switch.

6. When brewing is completed, simply discard the grounds and filter.

CLEANING

1. The use of a damp cloth rinsed in any mild, non-abrasive, liquid detergent is recommended for cleaning all

surfaces on Bunn-O-Matic equipment.

2. Check and clean the sprayhead. The sprayhead holes must always remain open.

3. With the sprayhead removed, insert the deliming spring (provided) all the way into the sprayhead tube.

When inserted properly, no more than two inches of spring should be visible. Saw back and forth five or
six times.

NOTE – In hard water areas, this may need to be done daily. It will help prevent liming problems in the brewer
and takes less than a minute.

Page 7

10841 020503

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 qualied service person­nel.

• All electronic components have 120 volt ac and low voltage dc potential on their terminals. Shorting of

terminals or the application of external voltages may result in board failure.

• Intermittent operation of electronic circuit boards is unlikely. Board failure will normally be permanent. If

an intermittent condition is encountered, the cause will likely be a switch contact or a loose connection at a
terminal or crimp.

• Solenoid removal requires interrupting the water supply to the valve. Damage may result if solenoids are

energized for more than ten minutes without a supply of water.

• The use of two wrenches is recommended whenever plumbing 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 specied.

• Follow recommended service procedures

• Replace all protective shields or safety notices

PROBLEM

Brew cycle will not start (CT,
CTF, CWT, CWTA, CWTB, CWTF,
CWTFA, CWTFB, SINGLE CW &
SINGLE CWF)

PROBABLE CAUSE

1. No water

2. No power or incorrect voltage
to the brewer

REMEDY

Water lines and valves to the
brewer must be open.

(A1) Check the terminal block for
120 volts across the black and
white terminals on two wire 120
volt brewers.
(A2) Check the terminal block
for 120 volts across the red and
white terminals and the black
and white terminals on three wire
120/240 volt brewers.
(A3) Check the terminal block for
200 volts on "B Series" brewers
or 230 volts on "A Series" brew­ers across the red and black
terminals.

Page 8

(B) Check circuit breakers or
fuses.

10841 020503

TROUBLESHOOTING (cont.)

PROBLEM

Brew cycle will not start (cont.) (CT,
CTF, CWT, CWTA, CWTB, CWTF,
CWTFA, CWTFB, SINGLE CW &
SINGLE CWF)

PROBABLE CAUSE

3. ON/OFF Switch

4. Start Switch

5. Timer

6. Solenoid Valve

7. Water strainer/flow control
(.222 GPM)

REMEDY

Refer to Service - ON/OFF Switch
for testing. See page 17

Refer to Service - Start Switch for
testing procedures. See page 20

Refer to Service - Timer for testing
procedures. See page 24

Refer to Service - Solenoid Valve
for testing procedures. See page
19

(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. Tank Heater Switch

2. Limit Thermostat
CAUTION - Do not eliminate or
bypass limit thermostat. Use BOM
replacement part #29329.1000

3. Control Thermostat

4. Tank Heater

Refer to Service - Tank Heater
Switch for testing procedures.
See page 22

Refer to Service - Limit Thermo­stat for testing procedures. See
page 16

Refer to Service - Control Ther­mostat for testing procedures.
See page 15

Refer to Service - Tank Heater for
testing procedures. See page 21

Page 9

10841 020503

TROUBLESHOOTING (cont.)

PROBLEM

Inconsistent beverage level in
dispenser

PROBABLE CAUSE

1. Strainer/flow control (.222
GPM) (CT,CTF, CWT, CWTA,
CWTB, CWTF, CWTFA, CWTFB,
SINGLE CW & SINGLE CWF)

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 (CT, CTF, CWT,
CWTA, CWTB, CWTF, CWTFA,
CWTFB, SINGLE CW & SINGLE
CWF)

Spitting or excessive steaming

4. Water Pressure (CT, CTF,
CWT, CWTA, CWTB, CWTF,
CWTFA, CWTFB, SINGLE CW &
SINGLE CWF)

1. Timer

2. Strainer/flow Control (.222
GPM)

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 10

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

(Early models) Timer dial must
indicate at least two minutes and
fifteen seconds.

(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.

10841 020503

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 (CT, CTF, CWT,
CWTA, CWTB, CWTF, CWTFA,
CWTFB, SINGLE CW & SINGLE
CWF)

REMEDY

Refer to Service - Control Ther­mostat for testing procedures.
See page 15

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.
See page 19

Water flows into tank continu­ously (ON/OFF Switch "ON")

Water flows into tank continu­ously (ON/OFF Switch "OFF")

Beverage overflows dispenser

1. Timer (CT, CTF, CWT, CWTA,
CWTB, CWTF, CWTFA, CWTFB,
SINGLE CW & SINGLE CWF)

1. Solenoid Valve (CT, CTF, CWT,
CWTA, CWTB, CWTF, CWTFA,
CWTFB, SINGLE CW & SINGLE
CWF)

1.Dispenser

2. Timer (CT, CTF, CWT, CWTA,
CWTB, CWTF, CWTFA, CWTFB,
SINGLE CW & SINGLE CWF)

3. Solenoid Valve (CT, CTF, CWT,
CWTA, CWTB, CWTF, CWTFA,
CWTFB, SINGLE CW & SINGLE
CWF)

Refer to Service - Timer for test­ing procedures. See page 24

Remove the Solenoid Valve and
clean any obstruction. Rebuild
or replace the valve if necessary.
See page 19

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

Refer to Service - Timer for test­ing procedures. See page 24

Remove the Solenoid Valve and
clean any obstruction. Rebuild
or replace the valve if necessary.
See page 19

Page 11

10841 020503

TROUBLESHOOTING (cont.)
PROBLEM

Weak beverage

PROBABLE CAUSE

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 clean spray-head 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 195°F (76°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
(CT, CTF, CWT, CWTA, CWTB,
CWTF, CWTFA, CWTFB, SINGLE
CW & SINGLE CWF)

1. Funnel Loading

1. Solenoid

2. Plumbing Lines

3. Water Supply

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).

Page 12

10841 020503

TROUBLESHOOTING (cont.)

PROBLEM

Brewer is making unusal noises
(cont.)(CT, CTF, CWT, CWTA,
CWTB, CWTF, CWTFA, CWTFB,
SINGLE CW & SINGLE CWF)

Brewer is making unusal noises
(C)

Low beverage serving tempera­ture

Brewer does not change volume
when half/full switch is changed.

PROBABLE CAUSE

4. Tank Heater

1. Tank Heater

1. Warmer

1. Selector switch

REMEDY

Remove and clean lime off the
tank heater. See page 21

Remove and clean lime off the
tank heater. See page 21

Refer to Service - Warmer ele­ment for testing procedures. See
page 27

Refer to Service - Selector
switch testing procedures.
See page 20

Page 13

10841 020503

CAUTI ON :

W

A

R

M

E

R

S

A

N

D

S

U

R

F

A

C

E

S

A

R

E

H

O

T

CAUTION

!

BUNN

POUR IN W

ATER ONLY

CAUTION :

WARMERS AND SURFACES ARE HOT

CAUTION

!

BUNN

CAUTION :

WARMERS AND SURFACES ARE HOT

CAUTION

!

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 warmer
plate(s).

The top cover is attached with one #4-40 screw.

The front inspection panel is attached with #6-32
screws.

MODEL C

The warmer assembly is attached with three #4-40

screws.

Contents

Control Thermostat ..............................................15

Limit Thermostat ..................................................16

ON/OFF Switch .....................................................17

Solenoid (Inlet) ....................................................19

Start Switch (Brew) ............................................. 20

Selector Switch ................................................... 20

Tank Heater ......................................................... 21

Tank Heater Switch .............................................22

Timer .................................................................. 24

Warmer Element ................................................. 27

Wiring Diagrams .................................... 28 thru 32

Page 14

MODEL SINGLE CW

FIG. 1 COMPONENT ACCESS

MODEL CWT

P1152

10841 020503

SERVICE (cont.)

CONTROL THERMOSTAT

MODEL C

3. Check the voltage across the blue wire on the
control thermostat and the white insert on
two pole 120 volt terminal block or three pole
120/240 volt terminal blocks and the red insert
on two wire 200 volt or 240 volt terminal block
with a voltmeter. Connect the brewer to the power
source. The indication must be:

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

three wire 120/240 volt models.

b) 200 to 230 volts ac for two wire 200 volt or

230 volt models.

4. Disconnect the brewer from the power source.

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

5. 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 insert on the two
pole 120 volt or three pole 120/240 volt terminal
block and the red insert on the two pole 200 volt
or 230 volt terminal block with a voltmeter when
the control 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 and

three wire 120/240 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.

MODEL CWT

MODEL SINGLE CW

P1153

FIG. 2 THERMOSTAT LOCATION

Location:

The control thermostat is located inside the trunk

on the left side of the component bracket.

Test Procedures:

1. Disconnect the brewer from the power source.

2. Locate the blue wire on the control thermostat.

If voltage is present as described, reinstall the capil­lary tube into the tank to the line 4.5" (6.0" for Single
CW models) above the bulb, the control thermostat
is operating properly.
If voltage is not present as described, replace the
thermostat.

Removal and Replacement:

1. Remove wires from control thermostat leads.

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 #8-32 screw securing the con­trol thermostat to the component bracket in the
trunk.

Page 15

10841 071000

SERVICE (cont.)

CONTROL THERMOSTAT (cont.)

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 posi­tion.

LIMIT THERMOSTAT

P1153

FIG. 4 LIMIT THERMOSTAT LOCATION

NOTE - The capillary tube must be clear of any electri-

cal termination and not kinked.

7. Early Models: Using two #8-32 screws secure
the control thermostat inside the hood.

Late Models. Using one #8-32 screw secure the

control thermostat to the component bracket
inside the trunk.

8. Refer to the illustration below when reconnecting
the wires.

9. Adjust the control thermostat as required.

BLU to BLU Wire from Limit
Thermostat

BLU to BLU Wire from Tank Heater
(Brewers W/Out Faucet)
BLK to Thermal Cut-Off from Tank
Heater (Brewers with Faucet)

Early Models

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.

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 illustration below when reconnecting
the wires.

Late Models

FIG. 3 THERMOSTAT WIRING

P1129

Page 16

BLK to Tank
Heater Switch

FIG. 5 LIMIT THERMOSTAT WIRING

BLU to BLU Lead from
Control Thermostat

P1800

10841 071000

BUNN

C

W

S

ER

IES

READY

ON/LOW

ER

START

BUNN

C

W

SE

RIES

READY

ON/LOWER START

BUNN

C

W

SE

R

IES

READY

ON/LOW

ER START

BUNN

C

W

SE

R

IES

READY

ON/LOW

ER START

BUNN

CW

S

ER

IES

READY

ON/LOWER START

CAUTION

!

BUNN

LOWER

POUR IN WATER ONLY

CAUTION

!

BUNN

LOWER

POUR IN WATER ONLY

CAUTION

!

BUNN

POUR IN WATER ONLY

CAUTION

!

BUNN

POUR IN WATER ONLY

L

O

W

E

R

T

O

P

LOWER

FRONT-SIDE-REAR

TOP

LOWER

FRONT-SIDE-REAR

SERVICE (cont.)

ON/OFF SWITCH - MODEL C

ON/OFF SWITCH - MODEL CWT & SINGLE CW

ONE LOWER WARMER

ONE LOWER WARMER

ONE LOWER & ONE UPPER WARMER

THREE LOWER WARMERS (LEFT

OR RIGHT) OR ONE LOWER &

TWO UPPER WARMERS

ONE LOWER & ONE UPPER WARMER

THREE LOWER WARMERS OR ONE
LOWER & TWO UPPER WARMERS

ONE UPPER & THREE LOWER
WARMERS (LEFT OR RIGHT)

FIG. 6 ON/OFF SWITCH LOCATION

P1155

ONE UPPER & THREE
LOWER WARMERS

FIG. 7 ON/OFF SWITCH LOCATION

Location:

The ON/OFF switch(s) are located on the front of

the hood.

Page 17

P1156

10841 020503

SERVICE (cont.)

ON/OFF SWITCH (cont.)

Test Procedure:

1. Disconnect the brewer from the power
source.

2. Viewing the switch from the back remove the
white or red wire from the upper terminal and
the black wire from the center terminal.

3. Check the voltage across the white wire or red
wire and the black wire with a voltmeter. Connect
the brewer to the power source. The indication
must be:

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

three wire 120/240 volt models.

b) 200 to 230 volts ac for two wire 200 or 230

volt models.

4. Disconnect the brewer from the power source.

If voltage is present as described, reconnect the white
or red wire and proceed to #5.
If voltage is not present as described, refer to the Wiring
Diagrams and check the brewer wiring harness.

WHI to Terminal Block (White
Insert on 120V or 120/240V
Models)
RED to Terminal Block (Red
Insert on 200V or 230V
Models)

BLK to Terminal Block (Black
Insert)

Terminal #1 (See chart below)

P1918

Connect wire to Terminal #1 as follows:

Lower Warmer ........................................................WHI/RED

One Top Warmer .............................................................. VIO

Two Top Warmers

(Front) ..................................................................... BRN/BLK

(Rear) ............................................................................... VIO

Two Top Warmers (1 Switch) ........................................... VIO

Side Warmers

(Front) ..................................................................... BRN/BLK

(Rear) ............................................................................... VIO

FIG. 8 ON/OFF SWITCH WIRING

5. With the black wire removed, remove the wire
from the lower terminal.

6. Check for continuity across the center and lower
terminal with the switch in the "ON" position.
Continuity must not be present when the switch
is in the "OFF" position.

If continuity is present as described, reconnect the
black wire to the center terminal and the wire to the
lower terminal.
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 switch in the hood.

4. Refer to the following illustration when recon­necting the wires.

Page 18

10841 071000

SERVICE (cont.)

SOLENOID VALVE - CT, CWT & SINGLE CW

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

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.

P1153

FIG. 9 SOLENOID VALVE LOCATION

Location:
The solenoid valve is located inside the trunk
on the lower center part of the component bracket.

Test Procedures:

1. Disconnect the brewer from the power source.

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

3. Check the voltage across the white/blue and white/
green wires with a voltmeter. Connect brewer to
power source. The indication must be:

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

three wire 120/240 volt models.

b) 200 to 230 volts ac for two wire 200 or 230

volt models.

4. Disconnect brewer from the power source,

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.

Removal and Replacement:

1. Remove the white/blue and white/green from the
solenoid valve.

2. Turn-off the water supply to the brewer.

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

4. Remove the two #8-32 screws securing the
solenoid mounting bracket to the component
bracket. Remove solenoid bracket and solenoid
valve as an assembly.

5. Remove the two #10-32 screws and lockwash­ers securing the solenoid valve to the solenoid
bracket.

6. Using two #10-32 screws and lockwashers in­stall new solenoid valve on solenoid mounting
bracket.

7. Using two #8-32 screws install solenoid valve
and bracket to the component bracket.

8. Securely fasten the water lines to and from the
solenoid valve.

9. Refer to the illustration below when reconnecting
the wires.

WHI/BLU from Timer

WHI/GRN from Timer

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

If continuity is present as described, reconnect the
white/blue and white/green wire from the timer.

Page 19

FIG. 10 SOLENOID VALVE WIRING

P1132

10841 020503

SERVICE (cont.)

SELECTOR SWITCH - SINGLE CW only

P1153

FIG. 11 BATCH SELECTOR SWITCH LOCATION

Location:
The batch selector switch is located on the
front of the hood to the right of the start switch.

Test Procedure:

1. Disconnect the brewer from the power supply.

2. Disconnect the pink and tan wires from the switch
terminals.

3. Check for continuity across the two terminals
on the switch when it is in the both positions.
Continuity must be present across these terminals
only in the full position.

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

Removal and Replacement:

1. Remove the pink and tan wires from the
switch.

2. Compress the clips inside the hood and gently
push the switch through the opening.

3. Push new switch into the opening and spread
the clips to hold the switch in the hood.

4. Refer to the following illustration when recon­necting the wires.

START SWITCH - CT, CWT & SINGLE CW

P1153

FIG. 13 START SELECTOR SWITCH LOCATION

Location:
The start switch is located in the center front
of the hood.

Test Procedure:

1. Disconnect the brewer from the power supply.

2. Disconnect the blue wire from the top switch
terminal and the white/red from the bottom switch
terminal.

3. Check for continuity across the two terminals on
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
blue wire to the top terminal and the white/red to the
bottom terminal.
If continuity is not present as described, replace the
switch.

Removal and Replacement:

1. Remove the blue wire and white/red from the
start switch.

2. Compress the clips inside the hood and gently
push the switch through the opening.

3. Push new switch into the opening and spread
the clips to hold the start switch in the hood.

4. Refer to the following illustration when recon­necting the wires.

PNK from timer

TAN from timer

P1918

FIG. 12 BATCH SELECTOR SWITCH WIRING

Page 20

BLU to BLU Lead
from Timer P1

WHI/RED to ON/OFF
Switch

P1133

FIG. 14 START SELECTOR SWITCH WIRING

10841 020503

SERVICE (cont.)

TANK HEATER

P1153

FIG. 15 TANK HEATER LOCATION

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. Check the voltage across the black and white
wires on 120 volt models or the black and red
wires for 120/240 volt models, 200 volt models
and 230 volt models with a voltmeter. Connect
the brew to the power source. The indication
must be:

a) 120 volts ac for two wire 120 volt 15 and 20

amp models.

b) 240 volts ac for three wire 120/240 volt mod-

els.

c) 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.

4. Disconnect the black wire and the white 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.

NOTE- If the tank heater remains unable to heat, remove
and inspect heater for cracks in the sheath.

Removal and Replacement:

1. Disconnect the water supply tube from the fill
basin.

2. Remove the tank inlet fitting securing the fill
basin to the tank lid, remove fill basin and tank
inlet gasket. Set all three parts aside for reas­sembly.

3. On brewers with faucet shut-off water supply to
the brewer and disconnect the inlet and outlet
water lines to the faucet coil assembly.

4. Disconnect the black wire on the limit thermostat
from the tank heater switch. On late model brew­ers also disconnect the blue wire from the limit
thermostat to the control thermostat.

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

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

7. Remove the eight #8-32 nuts securing the tank
lid to the tank.

8. Remove the tank lid with limit thermostat, spray­head tube, tank heater, coil assembly and control
thermostat w/bracket (early models only).

9 Remove the two hex nuts securing the tank heater

to the tank lid. Remove tank heater with gaskets
and discard.

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

11. Install tank lid with limit thermostat, sprayhead
tube, tank heater, coil assembly (brewers with
faucet) and control thermostat with bracket (early
brewers only) using eight #8-32 hex nut.

12. Reconnect the inlet and outlet water lines to the
faucet coil assembly.

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

Page 21

10841 020503

SERVICE (cont.)
TANK HEATER (Cont.)

14. Install sprayhead.

15. Reconnect the wires to the limit thermostat,
tank heater and control thermostat. See limit
thermostat and control thermostat sections in
this manual when reconnecting wires.

16. Install fill basin, secure with tank inlet fitting and
gasket. Insert water supply line through grommet
in fill basin.

17. Refer to the illustration below when reconnecting
the tank heater wires.

WHI to Terminal Block
(White Insert on 120V
Two Wire Models)
RED to Terminal Block
(Red Insert on 120/240V
Threee wire Models or
200V and 230V Two
Wire Models)

BLK to Control Ther­mostat (Brewers W/Out
Faucet) Thermal Cut-Off
to BLK from Control
Thermostat (Brewers
W/Faucet

TANK HEATER SWITCH

P1153

FIG. 17 TANK HEATER SWITCH LOCATION

FIG. 16 TANK HEATER WIRING

P1168

Location:
The tank heater switch is located on the rear
of the brewer on the upper left side of the trunk.

Test Procedure:

1. Disconnect the brewer from the power source.

2. Disconnect the black wire from the limit thermo­stat.

3. With the tank heater switch in the "ON" position
check the voltage between the black wire removed
from the limit thermostat and the white wire or red
wire on the tank heater with a voltmeter. Connect
the brewer to the power source. The indication
must be:

a) 120V volts ac on two wire 120 volt models.
b) 240 volts ac on three wire 120/240 volt mod-

els.

c) 200 to 230 volts ac on 200 volt or 230 volt

models.

4. Disconnect the brewer from the power source.

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

Page 22

10841 020503

SERVICE (cont.)
TANK HEATER SWITCH (cont.)

5. Check for continuity between the black wire re­moved from the limit thermostat and the black
insert on the terminal block. with the tank heater
switch in the "ON" upper position. Continuity
should not be present in the "OFF" lower posi­tion.

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

Removal and Replacement:

1. Shut-off and disconnect the incoming water sup­ply to the brewer.

2. On automatic brewers gently remove the fill tube
from back of fill basin.

3. Remove the tank inlet fitting securing fill basin
the tank lid. Remove fill basin and gasket. Set all
three parts aside for reassembly.

4. On brewers with faucets, disconnect the water
supply to coil assembly and remove the tube
from the tank to the faucet.

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

6. Disconnect the wires on the limit thermostat and
the tank heater and the control thermostat (early
models).

7. Gently pull the thermostat sensor and grommet
from the tank lid.

8. Insert a tube to the bottom of the tank and
syphon ALL of the water out. (BUNN-O-MATIC
has #12440 syphon assembly available for this
purpose.

9. Gently reinstall the thermostat sensor and grom­met in the tank lid.

10. Remove the two #8-32 screws securing the tank
assembly to the hood.

11. Lift tank and components out as an assembly
and set aside for reassembly.

12. Disconnect the two black wires from the tank
heater switch.

13. Remove the plastic facenut, hex facenut and the
switch indicator/guard bracket that secures tank
heater switch to the rear of the brewer. Remove
switch and discard.

14. Insert new tank heater switch through the hole in
the upper left rear of the trunk and secure with
switch indicator/guard bracket, hex facenut and
plastic facenut.

15. Reconnect the two black wires to the tank heater
switch terminals.

16. Set tank assembly inside the hood on mounting
brackets and secure with two #8-32 screws.

17. Reconnect the wires to the limit thermostat, tank
heater and the control thermostat. Refer to limit
thermostat, tank heater and control thermostat
sections in this manual when reconnecting
wires.

18. Brewers with faucet reinstall the faucet tube and
reconnect the water supply tube to the coil as­sembly.

19. Secure the sprayhead tube to the hood using hex
nut.

20. Install sprayhead.

21. Install fill basin, inlet gasket and secure to tank
lid with tank inlet fitting.

22. Carefully install water fill tube into the back of
the fill basin.

23. Reconnect and turn on the incoming water sup­ply.

24. Refer to the illustration below when reconnecting
the wires.

BLK to Limit Thermostat

BLK to Terminal Block
(Black Insert)

P1135

FIG. 18 TANK HEATER SWITCH WIRING

Page 23

10841 020503

SERVICE (cont.)

DIAL TIMER (Early Models) - CT & CWT

Dial Timer

P1153

FIG. 19 TIMER LOCATION

Location:
The timer is located inside the front of the
trunk on the upper right side of component bracket.

Test Procedure (Dial Timer).

1. Disconnect the brewer from the power source.

2. Disconnect the polarized, three pin connector
from the brewer wiring harness and rotate the
brew timer dial fully counterclockwise.

3. Check the voltage across sockets P2 & P3 (white
and black wires) of the female connector with a
voltmeter when the "ON/OFF" is in the "ON" posi­tion (upper). Connect the brewer to the power
source. The indication must be:

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

three wire 120/240 volt models.

b) 200 to 230 volts ac on two wire 200 volt or

230 volt models.

4. Disconnect the brewer from the power source.

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

with a voltmeter when the "ON/OFF" switch is in the

"ON" position (upper) and start switch pressed.
Connect the brewer to the power source. The
indication must be:

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

three wire 120/240 volt models.

b) 200 to 230 volts ac for two wire 200 volt or

230 volt models.

6. Disconnect the brewer from the power source.

7. Reconnect the three pin connector from main
wiring harness to the timer.

If voltage is present as described, proceed to #7
If voltage is not present as described, refer to Wiring
Diagrams and check the brewer wiring harness.

7. Disconnect the black and white wires from the
solenoid.

8. Check the voltage across the black and white
wires with a voltmeter when the "ON/OFF" switch
is in the "ON" position (upper) and the "START"
switch is pressed to the "START" position (lower)
and released. Connect the brewer to the power
source. The indication must be:

a) 120 volts ac for approximately 20 seconds for

two wire 120 volt models and three wire 120/240
volt models.

b) 200 to 230 volts ac for approximately 20 sec-

onds for two wire 200 volt or 230 volt models.

If voltage is present as described, the brew timer is
operating properly. Reset the timer dial as required,
to obtain the desired brew volume.
If voltage is not present as described, replace the
timer.

Removal and Replacement (Dial Timer):

1. Disconnect the timer socket from the brewer wir­ing harness and the timer leads from the solenoid
valve.

2. Remove the one #8-32 screw securing timer to
component bracket.

3 Install new timer on component bracket securing

with one #8-32 screw.

4. Refer to the following illustration when recon­necting the wires.

5. Readjust the timer dial as required.

5. Check the voltage across the sockets P1 & P2
(blue and white wires) of the female connector

Page 24

10841 020503

SERVICE (cont.)
DIAL TIMER (Early Models) (cont.)

To Main Wiring Harness

WHI to Solenoid Valve

2. Remove the #8-32 screw 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 and

three wire 120/240 volt models.

b) 200 to 230 volts ac on two wire 200 volt or

230 volt models.

5. Disconnect the brewer from the power source.

BLK to Solenoid Valve

Dial Timer

FIG. 20 TIMER WIRING

DIGITAL BREW TIMER (Late Models)

P1136

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

6. 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.
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 and

three wire 120/240 volt models.

b) 200 to 230 volts ac on two wire 200 volt or

230 volt models.

FIG. 21 DIGITAL BREW TIMER

P2203.45

Location:
The timer is located inside the front of the trunk
on the upper right side of component bracket.

Test Procedure (Digital Timer):
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.

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 (Digital Timer):

1. Remove the #8-32 screw securing circuit board
to the mounting bracket.

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

3. Remove all wires from the timer.

Page 25

10841 020503

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

4. Attach all wires to the replacement timer board
prior to installation to the component mounting
bracket. Refer to FIG. 22 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 (Digital):
NOTE: Prior to setting or modifying volumes, check
that the brewer is connected to water supply, the
tank is properly filled, and a funnel and server are in
place.
NOTE: All volume settings must be done with the
sprayhead installed.

1. Modifying brew volumes. To modify a brew vol-

ume, first check that the SET/LOCK switch is in the
“SET” position on the circuit board.

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 finish in order to
verify that the desired volume has been achieved.

selector switch in the half 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
approximately 50 ounces 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 coffee, volume will decrease
due to absorption by the coffee grounds.

3. Setting programming disable feature. If it be­comes 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.

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 finish in order to verify that the
desired volume has been achieved.

2. Setting brew volumes. To set a brew volume,

first check that the SET/LOCK switch is in the “SET”
position on the circuit board. Place the ON/OFF switch
in the “ON” position. Models Single CW only, place the

Page 26

BLU/BLK wire from TL5 to P1
WHI/GRN wire from TL4 to Solenoid
WHI/BLU wire from TL3 to Solenoid
WHI wire from TL2 to P2
BLK wire from TL1 to P3

FIG. 22 DIGITAL TIMER WIRING

P2037

10841 020503

SERVICE (cont.)
WARMER ELEMENT(S)

If continuity is present as described, reconnect the
white or red and white/red, and brown/black or violet
wires on the warmer element.
If continuity is not present as described, replace the
warmer element.

Removal and Replacement:

1. Remove the three #4-40 screws securing the
warmer assembly to the brewer.

2. Lift the warmer assembly from the brewer.

3. Disconnect the two wires from the warmer element
terminals.

4. Remove the two #8-32 nuts securing the warmer
element to the warmer plate.

5. Securely install new warmer element.

6. Reconnect the two wires to warmer element ter­minals.

7. Securely install warmer assembly on the brewer.

8. Refer to the illustration below when reconnecting
the wires.

FIG. 23 WARMER LOCATION

P1158

Location:

The warmer element(s) is located under the warmer

plate.

Test Procedures:

1. Disconnect the brewer from the power source.

2. Use the white or red wire to the terminal block
and the white/red, brown/black or violet wire to
the "ON/OFF" switch.

3. Check voltage across the white or red and white/
red, brown/black or violet with a voltmeter with the
"ON/OFF" switch in the "ON" position. The indication
must be:

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

three wire 120/240 volt models.

b) 200 to 230 volts ac for two wire 200 or 230 volt

models.

4. Disconnect the brewer from the power source.

WHI/RED to ON/OFF Switch (One Lower Warmer)
BRN/BLK to ON/OFF Switch (Top Front Warmer
or Side Warmer)
VIO to ON/OFF Switch (Top Front Warmer or
Rear Side Warmer)

WHI to Terminal Block (120V or
120/240V Brewers)
WHI to Terminal Block (200V or
230V Brewers)

P1159

FIG. 24 WARMER WIRING

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 the continuity across the two terminals on

the warmer element.

Page 27

10841 071000

P3

BLK

P1, P2, & P3 ARE PINS OF A

POLARIZED THREE-PIN

CONNECTOR.

BLU

BLU/BLK

WHI

BREW
TIMER

P1

P2

WHI

OPTIONAL AUTOMATIC BREW CIRCUIT

SCHEMATIC WIRING DIAGRAM C, CT & CWT

P2

P1

FRONT

WHI

WHI

P3

WHI

BRN/BLK

VIO

WHI

REAR

WHI

WHIBLK

WHI/RED

LOWER WARMER

START SWITCH

WHI/RED

WHI/RED

L1

GRN

BLK

RED (MODEL 35)

WHI (MODELS 15 & 20)

N L2

HEATER
SWITCH

BLK

BLU

ON/OFF

SWITCH

WHI/RED

WHI

REAR

WHI

WHI

P3

P1

VIO

(FAUCET

OPTION ONLY)

THERMAL

FUSE

BLKBLK

LIMIT

THERMOSTAT

120/240 VOLTS AC 3 WIRE

120 VOLTS AC 2 WIRE

SINGLE PHASE

BLK

BRN/BLK

BLK

VIO

OPTIONAL DUAL WARMER ASSY (TOP OR SIDE)

BLK

OPTIONAL SINGLE TOP WARMER ASSY

VIO WHI

WHI

OPTIONAL FRESH LIGHT SYSTEM

WHI

WHI/ORA

READY

BLK

BLU

SW. & THERMOSTAT

TANK HEATER

"KEEP WARM" HEATER

GRY

L.E.D.

PNK

INDICATOR

TIMER

4
3
2
1

SOL

T1 T5 T3

T4
T2

WHI/BLU

WHI/GRN

1

3

2

1

3

2

1

3

2

1

3

2

Page 28

10841 071000

P3

P1, P2, & P3 ARE PINS OF A

POLARIZED THREE-PIN

CONNECTOR.

BLU

P1

RED

OPTIONAL AUTOMATIC BREW CIRCUIT

SCHEMATIC WIRING DIAGRAM CWTB

P2

P1

FRONT

RED

RED

P3

RED

BRN/BLK

VIO

RED

REAR

RED

RED

REDBLK

WHI/RED

LOWER WARMER

START SWITCH

WHI/RED

WHI/RED

L1

GRN/YEL

BLK

L2

HEATER
SWITCH

BLK

BLU

ON/OFF SWITCH

WHI/RED

REAR

RED

RED

P3

P1

VIO

(FAUCET

OPTION ONLY)

THERMAL

FUSE

BLKBLK

LIMIT

THERMOSTAT

200 VOLTS AC 2 WIRE

SINGLE PHASE

BLK

BRN/BLK

BLK

VIO

OPTIONAL DUAL WARMER ASSY (TOP OR SIDE)

BLK

OPTIONAL SINGLE TOP WARMER ASSY

VIO RED

READY

BLK

BLU

SW. & THERMOSTAT

TANK HEATER

BLK

BLU/BLK

WHI

BREW
TIMER

P2

SOL

T1 T5 T3

T4
T2

WHI/BLU

WHI/GRN

1

3

2

1

3

2

1

3

2

1

3

2

Page 29

10841 071000

P3

P1, P2, & P3 ARE PINS OF A

POLARIZED THREE-PIN

CONNECTOR.

BLU

P1

RED

OPTIONAL AUTOMATIC BREW CIRCUIT

SCHEMATIC WIRING DIAGRAM CWTA

P2

P1

FRONT

RED

RED

P3

RED

BRN/BLK

VIO

RED

REAR

RED

WHI

RED

REDBLK

WHI/RED

LOWER WARMER

START SWITCH

WHI/RED

WHI/RED

L1

GRN/YEL

BLK

L2

HEATER
SWITCH

BLK

BLU

ON/OFF

SWITCH

WHI/RED

WHI

REAR

RED

RED

P3

P1

VIO

(FAUCET

OPTION ONLY)

THERMAL

FUSE

BLKBLK

LIMIT

THERMOSTAT

220-240 VOLTS AC

2 WIRE

SINGLE PHASE

BLK

BRN/BLK

BLK

VIO

OPTIONAL DUAL WARMER ASSY (TOP OR SIDE)

BLK

OPTIONAL SINGLE TOP WARMER ASSY

VIO RED

READY

BLK

BLU

SW. & THERMOSTAT

TANK HEATER

"KEEP WARM"

BLK

BLU/BLK

WHI

BREW
TIMER

P2

SOL

T1 T5 T3

T4
T2

WHI/BLU

WHI/GRN

1

3

2

1

3

2

1

3

2

1

3

2

Page 30

10841 071000

P3

BLK

P1, P2, & P3 ARE PINS OF A

POLARIZED THREE-PIN

CONNECTOR.

WHI

BLK

SOL

BLU BLU

WHI

BREW
TIMER

P1

P2

WHI

OPTIONAL AUTOMATIC BREW CIRCUIT

SCHEMATICWIRINGDIAGRAM

CWTF, CWTFB NO WARMER

WHI

BLK

START SWITCH

WHI/RED

WHI/RED

TANK HEATER

L1

GRN

BLK

RED (MODEL 35)

WHI (MODELS 15 & 20)

N

L2

HEATER
SWITCH

BLK

BLU

READY INDICATOR

BLU

SW. & THERMOSTAT

ON/OFF

SWITCH

WHI/RED

"KEEP WARM" HEATER

WHI

(FAUCET

OPTION ONLY)

THERMAL

FUSE

BLKBLK

LIMIT

THERMOSTAT

120/240 VOLTS AC 3 WIRE
100-120 VOLTS AC 2 WIRE

SINGLE PHASE

BLK

WHI

OPTIONAL FRESH LIGHT SYSTEM

BLK

4
3

2
1

PNK

GRY

L.E.D.

INDICATOR

TIMER

WHI

WHI/ORA

Page 31

10841 042401

READY INDICATOR

BLK

BLU

SW. & THERMOSTAT

P3

BLK

P1, P2, & P3 ARE PINS OF A

POLARIZED THREE-PIN

CONNECTOR.

WHI

BLK

SOL

BLU BLU

WHI

BREW
TIMER

P1

P2

WHI

OPTIONAL AUTOMATIC BREW CIRCUIT

SCHEMATICWIRINGDIAGRAM

CWTFA NO WARMER

RED

BLK

WHI/RED

WHI/RED

TANK HEATER

L1

GRN

BLK

RED

L2

HEATER
SWITCH

BLK

BLK

BLU

ON/OFF

SWITCH

WHI/RED

"KEEP WARM" HEATER

WHI

THERMAL

FUSE

THERMAL

FUSE

BLKBLK

LIMIT

THERMOSTAT

230 VOLTS AC

2 WIRE

SINGLE PHASE

WHI

OPTIONAL FRESH LIGHT SYSTEM

BLK

4
3

2
1

PNK

GRY

L.E.D.

INDICATOR

TIMER

WHI

WHI/ORA

START SWITCH

RED

RED

BLU

WHI

BREW
TIMER

SCHEMATIC WIRING DIAGRAM

SINGLE CW

WHI

WHI

WHI

WHIBLK

WHI/RED

LOWER WARMER

START SWITCH

WHI/RED

WHI/RED

L1

GRN

BLK

RED (MODEL 35)

WHI (MODELS 15 & 20)

N L2

HEATER
SWITCH

BLK

BLU

ON/OFF

SWITCH

WHI/RED

WHI

WHI

(FAUCET

OPTION ONLY)

THERMAL

FUSE

BLKBLK

LIMIT

THERMOSTAT

120/240 VOLTS AC 3 WIRE

120 VOLTS AC 2 WIRE

SINGLE PHASE

BLK

BRN/BLK

VIO

TAN

PNK

BLK

WHI

READY

BLK

BLK

SW. & THERMOSTAT

TANK HEATER

"KEEP WARM" HEATER

SOL

T1 T5 T3

T4
T2

WHI/BLU

WHI/GRN

1

3

2

P1

P3

P2

1

3

2

1

3

2

HALF/FULL

SWITCH

NO CONNECTION THIS APPLICATION

P1, P2, &

P3 ARE

PINS OF A
POLARIZED
THREE-PIN

CONNECTOR.

Page 32

10841 020503