Bunn CDBC-APS Instruction and safety manual

BUNN-O-MATIC CORPORATION
POST OFFICE BOX 3227
SPRINGFIELD, ILLINOIS 62708-3227
PHONE: [phone] F X: [phone]
www.bunnomatic.com
OPERATING & SERVICE MANUAL
BUNN
®
CEZ- PS, CDBC- PS,
CEZ-TS, CDBC-TS,
CEZ-TSR, CDBC-TSR
BUNN
MANUFACTUREDBYBUNN-O-MATICCORPORATION
SPRINGFIELD,ILLINOIS,U.S.A.
MODELS/N
VOLTSA.C.AMPWATTS
PHASEWIREHERTZ
COVEREDUNDERONEORMOREOFTHEFOLLOWINGPATENTS:
ONEORMOREOTHERPATENTSMAYBEPENDING
BUNN
MANUFACTUREDBYBUNN-O-MATICCORPORATION
SPRINGFIELD,ILLINOIS,U.S.A.
MODELS/N
VOLTSA.C.AMPWATTS
PHASEWIREHERTZ
COVEREDUNDERONEORMOREOFTHEFOLLOWINGPATENTS:
ONEORMOREOTHERPATENTSMAYBEPENDING

Page 2
INTRODUCTION
This equip ent will auto atically brew a half-gallon batch of coffee into an awaiting server at the press of a
button. A hot water faucet ay be included for allied beverage use. Most functions of the brewer are digitally
controlled. It is only for indoor use on a sturdy counter or shelf.
CONTENTS
Introduction & Warranty .................................................................................... 2
User Notices ...................................................................................................... 3
Electrical & Plu bing Require ents ................................................................. 4
Operating Controls............................................................................................. 5
Initial Set-Up, Coffee Brewing, & Cleaning......................................................... 6
CEZ-APS/TS/TSR Adjust ents & Optional Settings .......................................... 7
CDBC-APS/TS/TSR Adjust ents & Optional Settings ....................................... 8
Troubleshooting ................................................................................................. 9
Service............................................................................................................. 20
Wiring Diagra s .............................................................................................. 31
W RR NTY
Bunn-O-Matic Corp. (“Bunn”) warrants the equip ent anufactured by it to be co ercially free fro defects
in aterial and work anship existing at the ti e of anufacture and appearing within one year fro the date of
installation. In addition:
1.) Bunn warrants electronic circuit and/or control boards to be co ercially free fro defects in aterial and
work anship for two years fro the date of installation.
2.) Bunn warrants the co pressor on refrigeration equip ent to be co ercially free fro defects in aterial
and work anship for two years fro the date of installation.
3.) Bunn warrants that the grinding burrs on coffee grinding equip ent will grind coffee to eet original factory
screen sieve analysis for three years fro date of installation or for 30,000 pounds of coffee, whichever co es first.
This warranty does not apply to any equip ent, co ponent or part that was not anufactured by Bunn or that,
in Bunn’s judge ent, has been affected by isuse, neglect, alteration, i proper installation or operation, i proper
aintenance or repair, da age or casualty.
THE FOREGOING W RR NTY IS EXCLUSIVE ND IS IN LIEU OF NY OTHER W RR NTY, WRITTEN OR
OR L, EXPRESS OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, NY IMPLIED W RR NTY OF EITHER
MERCH NT BILITY OR FITNESS FOR P RTICUL R PURPOSE. The agents, dealers or e ployees of Bunn are
not authorized to ake odifications to this warranty or to ake additional warranties that are binding on Bunn.
Accordingly, state ents by such individuals, whether oral or written, do not constitute warranties and should not
be relied upon.
The Buyer shall give Bunn pro pt notice of any clai to be ade under this warranty by telephone at (217)
529-6601 or by writing to Post Office Box 3227, Springfield, Illinois, 62708-3227. If requested by Bunn, the Buyer
shall ship the defective equip ent prepaid to an authorized Bunn service location. If Bunn deter ines, in its sole
discretion, that the equip ent does not confor to the warranty, Bunn shall repair the equip ent with no charge
for parts during the warranty period and no charge for labor by a Bunn Authorized Service Representative during
the warranty period. If Bunn deter ines that repair is not feasible, Bunn shall, at its sole option, replace the
equip ent or refund the purchase price for the equip ent.
THE BUYER’S REMEDY G INST BUNN FOR THE BRE CH OF NY OBLIG TION RISING OUT OF THE S LE
OF THIS EQUIPMENT, WHETHER DERIVED FROM W RR NTY OR OTHERWISE, SH LL BE LIMITED, S
SPECIFIED HEREIN, TO REP IR OR, T BUNN’S SOLE OPTION, REPL CEMENT OR REFUND.
In no event shall Bunn be liable for any other da age or loss, including, but not li ited to, lost profits, lost sales,
loss of use of equip ent, clai s of Buyer’s custo ers, cost of capital, cost of down ti e, cost of substitute
equip ent, facilities or services, or any other special, incidental or consequential da ages.
29253 030101

Page 3
USER NOTICES
Carefully read and follow all notices in this anual and on the equip ent. All labels on the equip ent should
be kept in good condition. Replace any unreadable or da aged labels.

Page 4
ELECTRIC L REQUIREMENTS
C UTION - The brewer ust be disconnected fro the power source until specified in Initial Set-Up.
Model 15 has an attached cordset and requires 2-wire grounded service rated 120 volts ac, 15 a p, single
phase, 60 Hz.
Model 35 requires 3-wire, grounded service rated
120/208 or 120/240 volts ac, 20 a p, single phase, 60
Hz. Proceed as follows:
Model 20 requires 2-wire, grounded service rated
120 volts ac, 20 a p, single phase, 60 Hz. Proceed as
follows:
Electrical Hook-Up
C UTION – I proper electrical installation will da age electronic co ponents.
1. An electrician ust provide electrical service as specified.
2. Using a volt eter, check the voltage and color coding of each conductor at the electrical source.
3. Re ove the front panel beneath the sprayhead.
4. Feed the cord through the strain relief and connect it to the ter inal block.
5. Connect the brewer to the power source and verify the voltage at the ter inal block before proceeding.
Replace the front panel.
6. If plu bing is to be hooked up later be sure the brewer is disconnected fro the power source. If plu bing
has been hooked up, the brewer is ready for Initial Set-Up.
PLUMBING REQUIREMENTS
These brewers ust be connected to a cold water syste with operating pressure between 20 and 90 psi (138
and 620 kPa) fro 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 fitting is 1⁄4" flare. Bunn-O-Matic does not reco end the use of a reverse-os osis or deionized water supply
to this equip ent.
NOTE - Bunn-O-Matic reco ends 1⁄4" copper tubing for installations of less than 25 feet and 3⁄8" for ore than
25 feet fro the 1⁄2" water supply line. A tight coil of copper tubing in the water line will facilitate oving the brewer
to clean the countertop. Bunn-O-Matic does not reco end the use of a saddle valve to install the brewer. The
size and shape of the hole ade in the supply line by this type of device ay restrict water flow.
This equipment must be installed to comply with the Basic Plumbing Code of the
Building Officials and Code dministrators International, Inc. (BOC )
and the Food Service Sanitation Manual of the Food and Drug dministration (FD ).
Plumbing Hook-Up
1. Flush the water line.
2. Securely attach it to the flare fitting at the rear of the brewer.
3. Turn on the water supply.
NEUTRAL
WHITE
L1 BLACK
208 or 240V.A.C.
120V.A.C.
120V.A.C.
L2 RED
120V.A.C.
NEUTRAL
WHITE
L1 BLACK
29253 011900

Page 5
OPER TING CONTROLS
Model CEZ- PS/TS/TSR ON/OFF SWITCH
Placing the "ON/OFF" switch in the "ON" upper position enables the
brew circuit, and energizes the tank refill circuit. Placing the switch
in the "OFF" lower position stops tank refilling and brewing. Stop-
ping a brew cycle after it has been started will not stop the flow of
water into the server until the funnel is e pty.
NOTE – Hot water will be available at the faucet in a li ited a ount
when the switch is in the "OFF" position because the tank will not
refill.
ON/OFF SWITCH
Pressing the "ON/OFF" switch (indicator glowing) enables the brew
circuit and energizes the tank refill circuit. Pressing the switch again
(indicator not glowing) stops tank refilling and brewing. Stopping a
brew cycle after it has been started will not stop the flow of water into
the server until the funnel is e pty.
NOTE – Hot water will be available at the faucet in a li ited a ount
when the "ON/OFF" indicator is not glowing because the tank will not
refill.
BREW SWITCH
Mo entarily 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 ust be in the "ON" upper position to initiate and co plete a brew cycle.
RE DY INDIC TOR
This indicator glows when the preselected brew water te perature has been achieved.
Model CDBC- PS/TS/TSR
BREW SWITCH
Mo entarily pressing and releasing the switch starts a brew cycle when the "ON/OFF" indicator is glowing.
NOTE – The "ON/OFF" indicator ust be glowing to initiate and co plete a brew cycle.
RE DY INDIC TOR
This indicator glows when the preset te perature has been achieved. The word "NOT" above "READY" will glow
in all other instances.
TEMPER TURE INDIC TORS (Feature disabled from the factory – refer to page 8.)
The indicator glows to co unicate the brew water te perature. Two indicators will glow when the
te perature is between the .
P1911
P1910

Page 6
INITI L SET-UP
1. Insert an e pty funnel into the funnel rails.
2. Place an e pty server under the funnel.
3. Connect the brewer to the power source.
4. Model CDBC-APS/TS/TSR – Press the "ON/OFF" switch (indicator glowing).
Model CEZ-APS/TS/TSR – Place the "ON/OFF" switch in the "ON" upper position.
5. Water will flow into the tank and stop when the tank is filled to its capacity.
6. Wait approxi ately twenty inutes for the water in the tank to heat to the proper te perature.
7. Place a s all vessel beneath the faucet and open the faucet handle. Release it when you hear the tank refilling.
8. Model CDBC-APS/TS/TSR – Press the "ON/OFF" switch (indicator glowing) then o entarily press and
release the "BREW" switch.
Model CEZ-APS/TS/TSR – Place the "ON/OFF" switch in the "ON" upper position then o entarily press and
release the "BREW" switch.
9. Allow the cycle to finish and easure the a ount of water in the server. It should be 64 ounces ± 2. Refer
to the adjust ents section of this anual should the volu e need to be increased or decreased.
The brewer is now ready for use in accordance with the coffee brewing instructions below.
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 e pty server beneath the funnel.
5. Model CDBC-APS/TS/TSR – Press the "ON/OFF" switch (indicator glowing) then o entarily press and
release the "BREW" switch.
Model CEZ-APS/TS/TSR – Place the "ON/OFF" switch in the "ON" upper position then o entarily press and
release the "BREW" switch.
6. When brewing is co pleted, si ply discard the grounds and filter.
CLE NING
1. The use of a da p cloth rinsed in any ild, non-abrasive, liquid detergent is reco ended for cleaning all
surfaces on Bunn-O-Matic equip ent.
2. Check and clean the sprayhead. The sprayhead holes ust always re ain open.
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Page 7
CEZ- PS/TS/TSR DJUSTMENTS & OPTION L SETTINGS

Page 8
CDBC- PS/TS/TSR DJUSTMENTS & OPTION L SETTINGS
Setting Brew Temperature
The brewer is factory set to brew at 200°F(95°C). To change this setting, press and hold the "HIDDEN" switch
beneath the "®". The word "TEMP" above the "ON/OFF" switch will glow to correspond with the te porary function
change of this switch. Repeatedly press and release the "ON/OFF" switch until one of the bank of te perature
indicators shows the approxi ate desired te perature. When two indicators are glowing, the te perature is
approxi ately the nu ber between the .
Displaying Brew Temperature
The brewer is factory set with the te perature display disabled. To change this setting, press and hold the "ON/
OFF" switch and the "HIDDEN" switch beneath the "®" for five seconds, the entire bank of te perature indicators
will glow. Release both switches. Pressing and releasing the "ON/OFF" switch will toggle between turning the entire
bank of te perature indicators on-or-off, signifying the "ON" or "OFF" condition of this display. Wait for a few
seconds, the brewer will aintain this last setting.
Setting Brew Lockout
The brewer is factory set with the brew lockout disabled. Brew lockout prevents starting a brew cycle if the ready
indicator is not glowing. When an atte pt at brewing cannot be allowed, the word "NOT" and "LOCKOUT" flash for
three seconds to indicate the reason the brew can't begin. To change the condition of the brew lockout, press and
hold the "HIDDEN" switch beneath the "®" and o entarily press the "BREW" switch.
IMPORT NT: The tank must be full and fill solenoid shut off prior to making these adjustments.
djusting Brew Volumes
The brewer is factory set to deliver 64 ounces ± 2 for each brew cycle.
BREW VOLUME SET-UP: Use the following steps when the setting is unknown or a different circuit board is being
installed.
1. Place an e pty funnel in the funnel rails and an e pty server or graduated vessel beneath the funnel.
2. Place the "ON/OFF" switch in the "ON", upper position.
3. Press and hold the brew start button until you hear the brew solenoid click on-and-off three ti es
(approxi ately 5 seconds). Release the button.
4. Allow the cycle to continue until the desired a ount of water is dispensed and then turn "OFF" the brewer.
The brewer is now set to dispense this a ount of water for each subsequent brew cycle.
To increase the a ount of water for each brew cycle place an e pty funnel in the funnel rails and an e pty
server or graduated vessel beneath the funnel. Press the "ON/OFF" switch. Press and hold the "BREW" switch until
you hear the solenoid click on-and-off three ti es (approxi ately 5 seconds), then release the "BREW" switch.
Mo entarily press and release the "BREW" switch once for each ounce (approxi ate) of water to be added to the
prior setting and allow the brew cycle to finish.
To decrease the a ount of water for each brew cycle place an e pty funnel in the funnel rails and an e pty
server or graduated vessel beneath the funnel. Press the "ON/OFF" switch. Mo entarily press and release the
"BREW" switch once for each ounce (approxi ate) of water to be re oved fro the existing setting. Press and
hold the "BREW" switch until you hear the solenoid click on-and-off three ti es (approxi ately 5 seconds), then
release the "BREW" switch and allow the cycle to finish.
P1912
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Page 9
TROUBLESHOOTING
A troubleshooting guide is provided to suggest probable causes and re edies for the ost likely proble s
encountered. If the proble re ains after exhausting the troubleshooting steps, contact the Bunn-O-Matic
Technical Service Depart ent.
• Inspection, testing, and repair of electrical equip ent should be perfor ed only by qualified service personnel.
• All electronic co ponents have 120 volt ac and low voltage dc potential on their ter inals. Shorting of
ter inals or the application of external voltages ay result in board failure.
• Inter ittent operation of electronic circuit boards is unlikely. Board failure will nor ally be per anent. If an
inter ittent condition is encountered, the cause will likely be a switch contact or a loose connection at a
ter inal or cri p.
• Solenoid re oval requires interrupting the water supply to the valve. Da age ay result if solenoids are
energized for ore than ten inutes without a supply of water.
• The use of two wrenches is reco ended whenever plu bing fittings are tightened or loosened. This will help
to avoid twists and kinks in the tubing.
• Make certain that all plu bing connections are sealed and electrical connections tight and isolated.
• This brewer is heated at all ti es. Keep away fro co bustibles.
W RNING – • Exercise extre e caution when servicing electrical equip ent.
• Unplug the brewer when servicing, except when electrical tests are specified.
• Follow reco ended service procedures.
• Replace all protective shields or safety notices.
Before troubleshooting this brewer, check for the following:
A. Control Boards (CDBC-APS/TS/TSR)
1. Make sure ribbon cable is properly attached to the control board (ALL PINS INSERTED INTO PLUG).
2. Make sure there is a nylon insulating washer under each screw head that holds the control board to the plastic
front end cap. This is i portant for proper operation.
B. Control Boards (CEZ-APS/TS/TSR)
Locate J6 connector on control board. If ju per is across pins 1 & 2, board is set up to operate tea brewer or
a brewer that DOES NOT use a water level probe. If ju per is across pins 2 & 3, board is set up to operate a
coffee brewer or a brewer that uses a water level probe. Look at the botto side of the control board. Pin 1 of
connector J6 is arked by a square solder pad on the foil side of the board and pins 2,3 & 4 are arked by a
round solder pad.
C. Control Boards (CDBC-APS/TS/TSR & CEZ-APS/TS/TSR)
Make sure before servicing brewer that voltage is present at control board.
On CDBC-APS/TS/TSR odels, observe if indicator light is glowing on the control panel. If so, proceed with
testing. If not, check for voltage across pins 1 & 2 of the ten pin J1 connector (black and white wires). If voltage
is present, replace the control board. If voltage is not present, check wiring and voltage across ter inal block
(black and white). Correct the proble and retest before proceeding with testing.
On CEZ-APS/TS/TSR odels, check for voltage across pins 1 & 7 of the eight pin J1 connector (black and white
wires). If voltage is present, proceed with testing. If voltage is not present, check wiring and voltage across
ter inal block (black and white). Correct the proble and retest before proceeding with testing.
29253 071599

Page 10
Will not fill or refill
PROB BLE C USE REMEDYPROBLEM
1. Power off to brewer (CDBC-
APS/TS/TSR & CEZ-APS/TS/TSR)
2. Water shut off (CDBC-APS/TS/
TSR & CEZ-APS/TS/TSR)
3. Display flashing (CDBC-APS/
TS/TSR) or ready light flashing
(CEZ-APS/TS/TSR)
4. ON/OFF Switch (CDBC-APS/TS/
TSR & CEZ-APS/TS/TSR)
5. Li e build up on Probe (CDBC-
APS/TS/TSR & CEZ-APS/TS/TSR)
6. Refill Valve or Control Board
(CDBC-APS/TS/TSR & CEZ-APS/
TS/TSR)
Press ON/OFF switch on control
panel to deter ine if power is ON.
Make sure water is ON.
Brewer has shut down due to
alfunction (See Diagnostic Chart
in anual, Page 19, or under top
lid of brewer).
Make sure ON/OFF Switch is "ON"
and indicator is lit.
Re ove the Probe and check for
li e deposit on tip. Clean and
reinstall.
Disconnect the brewer fro the
power source and re ove wires
fro refill valve coil. Check for
continuity across the ter inals of
the solenoid coil. If continuity is
not present, replace the refill valve
(See page 30). If continuity is
present, the valve ay be stuck
closed. Shut water off to brewer.
Set the ON/OFF switch to the "OFF"
position. Open the faucet and drain
water down in the tank until flow
stops or slows to a trickle. Attach
a volt eter to the ter inals of the
refill solenoid. Connect the brewer
to the power source. Press the
switch "ON". Within five seconds,
voltage should be present at the
solenoid ter inals. If voltage is
not present, refer to the wiring
diagra s and check the wiring
harness.
TROUBLESHOOTING (cont.)
REFILL CIRCUIT
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Page 11
TROUBLESHOOTING (cont.)
Fill or refill does not shut "OFF"
(ON/OFF Switch "ON")
Fill or refill does not shut "OFF"
(ON/OFF Switch "OFF")
PROB BLE C USE REMEDYPROBLEM
1. Li e build up on probe (CDBC-
APS/TS/TSR & CEZ-APS/TS/TSR)
2a. Water Level Probe Sensing
Syste (CDBC-APS/TS/TSR)
2b. Water Level Probe Sensing
Syste (CEZ-APS/TS/TSR)
3. Refill valve or control board
(CDBC-APS/TS/TSR & CEZ-APS/
TS/TSR)
1. Refill valve or control board
(CDBC-APS/TS/TSR & CEZ-APS/
TS/TSR)
Re ove Probe and check for li e
deposits on tip. Clean and reinstall.
A) Disconnect the brewer fro the
power source. Disconnect the J3
connector fro the control board.
Check for continuity fro the nut
on top of the level probe to pin 1 of
the plug, continuity should be
present. Pull the te perature
probe up about an inch fro the
gro et. Check for continuity
fro the outside surface of the
te perature probe and pin 4 of the
plug, continuity should be present.
Connect the J3 plug to the control
board and proceed to step 3.
B) Disconnect the brewer fro the
power source. Disconnect the J5
connector fro the control board.
Check for continuity fro the nut
on top of the level probe to pin 5 of
the plug, continuity should be
present. Pull the te perature
probe up about an inch fro the
gro et. Check for continuity
fro the outside surface of the
te perature probe and pin 2 of the
plug, continuity should be present.
Connect the J5 plug to the control
board and proceed to step 3.
Press ON/OFF switch to "ON" (In-
dicator la p should be lit). If wa-
ter continuously flows out of air
vent tube, disconnect the brewer
fro the power source. If water
flow stops, replace the control
board. If water flow does not stop,
repair or replace the refill sole-
noid. (See page 30)
If water continuously flows out of
air vent tube, disconnect the
brewer fro the power source. If
water flow does not stop, repair or
replace the refill solenoid. If the
valve closes when power is re-
oved, replace the control board.
(See pages 21 & 22)
REFILL CIRCUIT (cont.)
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Page 12
TROUBLESHOOTING (cont.)
PROBLEM PROB BLE C USE REMEDY
HE TING CIRCUIT
1. Display flashing (CDBC-APS/
TS/TSR) or ready light flashing
(CEZ-APS/TS/TSR)
2. Water not touching te pera-
ture probe
3a. Dry Plug In Probe Sensing
Syste (CDBC-APS/TS/TSR)
3b. Dry Plug In Probe Sensing
Syste (CEZ-APS/TS/TSR)
Brewer has shut down due to
alfunction (See Diagnostic Chart
in anual, Page 19, or under top
lid).
Re ove probe and gro et. Look
into hole on tank lid. Water ust
be within one inch fro top of
tank.
A) Disconnect the brewer fro the
power source. Disconnect the J3
connector fro the control board.
Check for continuity fro the tank
ounting screw where the green
wire ounts, to pin 2 of the plug,
continuity should be present. Pull
the te perature probe up about
an inch fro the gro et. Check
for continuity fro the outside
surface of the te perature probe
and pin 4 of the plug, continuity
should be present. Connect the J3
plug to the control board and pro-
ceed to step 4a.
B) Disconnect the brewer fro the
power source. Disconnect the J5
connector fro the control board.
Check for continuity fro the tank
ounting screw where the green
wire ounts, to pin 4 of the plug,
continuity should be present. Pull
the te perature probe up about
an inch fro the gro et. Check
for continuity fro the outside
surface of the te perature probe
and pin 2 of the plug, continuity
should be present. Connect the J5
plug to the control board and pro-
ceed to step 4b.
Water does not heat to proper
te perature
IMPORTANT: Make sure no te -
perature tests are taken before the
ready light is "ON". Tank te pera-
ture ust be stabilized before read-
ings are taken.
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Page 13
TROUBLESHOOTING (cont.)
PROBLEM PROB BLE C USE REMEDY
Water does not heat to proper
te perature (cont.)
IMPORTANT: Make sure no te -
perature tests are taken before the
ready light is "ON". Tank te pera-
ture ust be stabilized before read-
ings are taken.
Spitting or excessive stea ing
4a. Te perature Probe (CDBC-
APS/TS/TSR)
4b. Te perature Probe (CEZ-APS/
TS/TSR)
5. Li it Ther ostat (CDBC-APS/
TS/TSR & CEZ-APS/TS/TSR)
6. Tank Heater (CDBC-APS/TS/
TSR & CEZ-APS/TS/TSR)
1. Li e build up on te perature
probe, tank or tank heater
A) Re ove the probe fro the
gro et and sub erge in a water
bath of approxi ately 70°F(21°C).
Connect an oh eter to pins 3
and 4 of the J3 connector. At
60°F(16°C) the reading should be
15.3k ± 2k OHMS, at 70°F(21°C)
the reading should be 11.8k ± 2k
OHMS, and at 80°F(27°C) the read-
ing should be 9.3k ± 2k OHMS. If
the probe is within these para -
eters, reconnect the J3 plug to the
control board.
B) Re ove the probe fro the
gro et and sub erge in a water
bath of approxi ately 70°F(21°C).
Connect an oh eter to pins 2
and 3 of the J5 connector. At
60°F(16°C) the reading should be
15.3k ± 2k OHMS, at 70°F(21°C)
the reading should be 11.8k ± 2k
OHMS, and at 80°F(27°C) the read-
ing should be 9.3k ± 2k OHMS. If
the probe is within these para -
eters, reconnect the J5 plug to the
control board.
Disconnect the brewer fro the
power source. Check for continu-
ity across the li it ther ostat ter-
inals. Continuity should be
present. If not replace the li it
ther ostat.(See page 27)
Disconnect the brewer fro the
power source. Check for continu-
ity between the white ter inal of
the ter inal block and the black
wire on the relay on the control
board. There should be a low OHM
reading. If no continuity is present,
check for a wiring proble , then
replace the tank heater if no wiring
proble is found.(See page 28)
Inspect probe and tank asse bly
for excessive li e deposits. Deli e
as required.
HE TING CIRCUIT (cont.)
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Page 14
TROUBLESHOOTING (cont.)
PROBLEM PROB BLE C USE REMEDY
Spitting or excessive stea ing
(cont.)
Brewer is aking unusual noises
2a. Te perature Probe (CDBC-
APS/TS/TSR)
2b. Te perature Probe (CEZ-APS/
TS/TSR)
3. Control Board (CDBC & CEZ)
1. Plu bing lines
2. Water supply
3. Li e build up
A) Re ove the probe fro the
gro et and sub erge in a water
bath of approxi ately 70°F(21°C).
Connect an oh eter to pins 3
and 4 of the J3 connector. At
60°F(16°C) the reading should be
15.3k ± 2k OHMS, at 70°F(21°C)
the reading should be 11.8k ± 2k
OHMS, and at 80°F(27°C) the read-
ing should be 9.3k ± 2k OHMS. If
the probe is within these para -
eters, reconnect the J3 plug to the
control board.
B) Re ove the probe fro the
gro et and sub erge in a water
bath of approxi ately 70°F(21°C).
Connect an oh eter to pins 2
and 3 of the J5 connector. At
60°F(16°C) the reading should be
15.3k ± 2k OHMS, at 70°F(21°C)
the reading should be 11.8k ± 2k
OHMS, and at 80°F(27°C) the read-
ing should be 9.3k ± 2k OHMS. If
the probe is within these para -
eters, reconnect the J5 plug to the
control board.
Set the te perature to 200°F
(95°C). Let tank te perature sta-
bilize. If te perature in tank is
above te perature setting by ore
than 7°F, replace the control
board.(See pages 21 & 22)
Plu bing lines should not rest on
the counter top.
The brewer ust be connected to
a cold water supply.
Re ove the tank lid and clean
inside of tank with a deli ing agent,
if necessary.
HE TING CIRCUIT (cont.)
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Page 15
TROUBLESHOOTING (cont.)
PROBLEM PROB BLE C USE REMEDY
BREWING CIRCUIT
Brew cycle will not start 1. Display flashing (CDBC-APS/
TS/TSR) or ready light flashing
(CEZ-APS/TS/TSR)
2. No water
3. No power or incorrect voltage to
the brewer
4. ON/OFF switch not in the "ON"
position
5. Low water te perature (Brew
lockout is enabled)
6. Water not touching refill probe
inside tank
7. Switch panel (CDBC-APS/TS/
TSR)
Brewer has shut down due to
alfunction (See Diagnostic Chart
in anual, Page 19, or under top
lid of brewer).
Water lines and valves to the
brewer ust be open.
Check for voltage across the black
and white ter inals at the ter i-
nal block.
The indicator la p ust be lit
Allow brewer to heat until ready
la p is lit, or disable the brew
lockout feature. (See page 7 or 8)
Press ON/OFF switch (indicator
ust be lit). Brewer will refill until
water touches probe inside tank.
Water ust be in contact with
refill probe before brew cycle will
start.
Disconnect the brewer fro the
power source. Disconnect the rib-
bon connector fro the control
board. Check for continuity be-
tween pins 1 & 2 (An arrow on the
connector indicates pin 1). No
continuity should be present. Press
the BREW switch. Continuity
should be present for as long as
the switch is held "ON". If no con-
tinuity is present, replace the
switch e brane decal.(See page
23)
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Page 16
TROUBLESHOOTING (cont.)
PROBLEM PROB BLE C USE REMEDY
BREWING CIRCUIT (cont.)
If the start switch (CEZ-APS/TS/
TSR) or switch panel (CDBC-APS/
TS/TSR) is operating properly,
proceed as follows. Attach a volt-
eter to the ter inals of the dis-
pense valve solenoid. Connect the
brewer to the power source. Turn
on the brewer and press the BREW
switch. Voltage should be present
at the solenoid ter inals. If volt-
age is not present, refer to the
wiring diagra s and check the
wiring harness. If voltage is
present, check for continuity
across the ter inals of the sole-
noid coil. If continuity is not
present, replace the solenoid valve
(See page 26). If continuity is
present, the valve ay be stuck
closed.
Set up brewer according to in-
structions in section djustments -
Brew Volumes. (See pages 7 or 8)
Using a stop watch or second hand,
ti e the length of the brew cycle.
Record this ti e inside the top lid.
If service is ever needed again, use
the ti e as reference to deter ine
if ti e has changed.
Inspect the dispense valve and
sprayhead for excessive li e de-
posits. Deli e as required.
Re ove dispense valve and clear
any obstructions. Rebuild or re-
place valve if necessary. (See page
26)
8. Control board or dispense valve
(CDBC-APS/TS/TSR & CEZ-APS/
TS/TSR)
1. Brew volu e (CDBC-APS/TS/
TSR & CEZ-APS/TS/TSR)
NOTE: All volu es to run with
sprayhead attached.
2. Li e build up
3. Dispense Valve
Brew cycle will not start (cont.)
Consistently low beverage level in
the dispenser or beverage over-
flows dispenser
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Page 17
TROUBLESHOOTING (cont.)
PROBLEM PROB BLE C USE REMEDY
BREWING CIRCUIT (cont.)
Dripping fro sprayhead
Weak beverage
1. Li e build up
2. Dispense valve
1. Sprayhead
2. Water te perature
3. Filter type
4. Coffee grind
5. Funnel loading
Inspect the tank asse bly for ex-
cessive li e deposits. Deli e as
required.
Re ove the dispense valve and
clear any obstructions. Rebuild or
replace the valve if necessary.(See
page 26)
A six-hole stainless steel spray-
head ust be used for proper
extraction.
Place an e pty brew funnel on an
e pty server beneath the spray-
head. Initiate brew cycle and check
the water te perature i edi-
ately below the sprayhead with a
ther o eter. The reading ust
not be less than 195°F(91°C). Ad-
just the te perature setting to in-
crease the water te perature.
Refer to Initial Set-up instructions.
BUNN® paper filters ust be used
for proper extraction.
A fine drip or grind ust be used
for proper extraction.
The BUNN® paper filter ust be
centered in the funnel and the bed
of grounds leveled by shaking
gently.
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Page 18
TROUBLESHOOTING (cont.)
PROBLEM PROB BLE C USE REMEDY
BREWING CIRCUIT (cont.)
Dry coffee grounds re ain in the
funnel
1. Sprayhead
2. Funnel loading
Make sure sprayhead is present
and holes are clear and unob-
structed. There should be six sepa-
rate strea s of water co ing out
of the sprayhead.
The BUNN® paper filter ust be
centered in the funnel and the bed
of grounds leveled by shaking gen-
tly.
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Page 19
DI GNOSTICS
Inter ittent flashing of the READY indicator (Model CEZ) or the bank of te perature indicators (Model CDBC)
indicates that a fault exists. Count the nu ber of flashes between pauses and use this chart as a guide to
investigating the fault.
FL SHES C USE THINGS TO CHECK
1 Dry Plug - In Fault - Water Pressure
Sheath of te perature probe dry for 10 inutes after power-up Te perature probe wiring
Fill valve wiring, function, & strainer
Green wire between tank and circuit board
2 Low Tank Level Fault - Water pressure
Level probe dry for 7 inutes after fill valve is energized Level probe wiring
Te perature probe wiring
Fill valve wiring, function, & strainer
3 Low Water Te perature Fault - Tank heater wiring & function
Sensor in tank is calling for heat for 30 inutes or ore Te perature probe wiring
4 Tank Sensor Disagree ent - Te perature probe wiring
Level probe detects water, but dry plug-in probe dry Level probe wiring
Green wire between tank and circuit board
5 Te p Sensor Out-of-Range - High Sensor not connected to circuit board
6 Te p Sensor Out-of-Range - Low Sensor wires shorted together or to chassis
29253 071599

Page 20
BUNN
MANUFACTUREDBYBUNN-O-MATICCORPORATION
SPRINGFIELD, ILLINOIS,U.S.A.
MODELS/N
VOLTSA.C.AMPWATTS
PHASEWIREHERTZ
COVEREDUNDERONEORMOREOFTHEFOLLOWINGPATENTS:
ONEORMOREOTHERPATENTSMAYBEPENDING
DISCONNECT FROM POWER SOURCE
BEFORE REMOVAL OF ANY PANEL OR
REPLACEMENT OF ANY COMPONENT!
WARNING
!
CAUTION:
WARMERSANDSURFACESAREHOT
BUNN
MANUFACTUREDBYBUNN-O-MATICCORPORATION
SPRINGFIELD, ILLINOIS,U.S.A.
MODELS/N
VOLTSA.C.AMPWATTS
PHASEWIREHERTZ
COVEREDUNDERONEORMOREOFTHEFOLLOWINGPATENTS:
ONEORMOREOTHERPATENTSMAYBEPENDING
SERVICE
This section provides procedures for testing and
replacing various ajor co ponents used in this
brewer should service beco e necessary. Refer to
Troubleshooting for assistance in deter ining the
cause of any proble .
W RNING - Inspection, testing, and repair of electri-
cal equip ent should be perfor ed only by qualified
service personnel. The brewer should be unplugged
when servicing, except when electrical tests are re-
quired and the test procedure specifically states to
plug-in the brewer.
COMPONENT CCESS
W RNING - Disconnect the brewer fro the power
source before the re oval of any panel or the replace-
ent of any co ponent.
All co ponents are accessible by the re oval of
the top cover or war er housing and front access
panel.
The top cover is attached with one #4-40 screw.
The front access panel is attached with four #6-32
screws.
P1913
Contents
Control Board - CDBC-APS/TS/TSR ...................21
Control Board - CEZ-APS/TS/TSR......................22
Switch Panel - CDBC-APS/TS/TSR ................... 23
ON/OFF Switch - CEZ-APS/TS/TSR ....................24
BREW Switch (Start) - CEZ-APS/TS/TSR...........25
Dispense Valve .................................................. 26
Li it Ther ostat ............................................... 27
Tank Heater .......................................................28
Refill Valve .........................................................30
Wiring Diagra s ............................................... 31
FIG. 1 COMPONENT ACCESS
29253 030101