Bunn CDBC TWIN User Manual

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CEZ CDBC TWIN

CAUTION :

OPERATING & SERVICE MANUAL

BUNN-O-MATIC CORPORATION

POST OFFICE BOX 3227

SPRINGFIELD, ILLINOIS 62708-3227

PHONE: (217) 529-6601 FAX: (217) 529-6644

www.bunnomatic.com

INTRODUCTION

This equipment will brew one or two half-gallon batches of coffee simultaneously into awaiting dispensers with just the press of a button. One side may include a hot water faucet 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 & Plumbing Requirements ................................................................. 4

Operating Controls............................................................................................. 5

Initial Set-Up, Coffee Brewing, & Cleaning......................................................... 6

CEZ Adjustments & Optional Settings................................................................ 7

CDBC Adjustments & Optional Settings............................................................. 8

CDBC Water Sensing Threshold Adjustment Procedure .................................... 9

CDBC Pulse Brew Setup Procedure ................................................................. 10

Troubleshooting ............................................................................................... 11

Diagnostics ...................................................................................................... 21

Service............................................................................................................. 22

Wiring Diagrams.............................................................................................. 34

BUNN-O-MATIC COMMERCIAL PRODUCT WARRANTY

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

1) All equipment other than as specified below: 2 years parts and 1 year labor.

2) Electronic circuit and/or control boards: parts and labor for 3 years.

3) Compressors on refrigeration equipment: 5 years parts and 1 year labor.

4) Grinding burrs on coffee grinding equipment to grind coffee to meet original factory screen sieve analysis: parts and labor for 3 years or 30,000 pounds of coffee, whichever comes first. These warranty periods run from the date of installation BUNN warrants that the equipment manufactured by it will be commercially free of defects in material and workmanship existing at the time of manufacture and appearing within the applicable warranty period. This warranty does not apply to any equipment, component or part that was not manufactured by BUNN or that, in BUNN’s judgment, has been affected by misuse, neglect, alteration, improper installation or operation, improper maintenance or repair, damage or casualty. This warranty is conditioned on the Buyer 1) giving BUNN prompt notice of any claim to be made under this warranty by telephone at (217) 529-6601 or by writing to Post Office Box 3227, Springfield, Illinois 62708-3227; 2) if requested by BUNN, shipping the defective equipment prepaid to an authorized BUNN service location; and 3) receiving prior authorization from BUNN that the defective equipment is under warranty.

THE FOREGOING WARRANTY IS EXCLUSIVE AND IS IN LIEU OF ANY OTHER WARRANTY, WRITTEN OR ORAL, EXPRESS OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, ANY IMPLIED WARRANTY OF EITHER MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. The agents, dealers or employees of BUNN are not authorized to make modifications to this warranty or to

make additional warranties that are binding on BUNN. Accordingly, statements by such individuals, whether oral or written, do not constitute warranties and should not be relied upon. If BUNN determines in its sole discretion that the equipment does not conform to the warranty, BUNN, at its exclusive option while the equipment is under warranty, shall either 1) provide at no charge replacement parts and/or labor (during the applicable parts and labor warranty periods specified above) to repair the defective components, provided that this repair is done by a BUNN Authorized Service Representative; or 2) shall replace the equipment or refund the purchase price for the equipment.

THE BUYER’S REMEDY AGAINST BUNN FOR THE BREACH OF ANY OBLIGATION ARISING OUT OF THE SALE OF THIS EQUIPMENT, WHETHER DERIVED FROM WARRANTY OR OTHERWISE, SHALL BE LIMITED, AT BUNN’S SOLE OPTION AS SPECIFIED HEREIN, TO REPAIR, REPLACEMENT OR REFUND.

In no event shall BUNN be liable for any other damage or loss, including, but not limited to, lost profits, lost sales, loss of use of equipment, claims of Buyer’s customers, cost of capital, cost of down time, cost of substitute equipment, facilities or services, or any other special, incidental or consequential damages.

BUNN, CDBC TWIN, and CDBCF TWIN are either trademarks or registered trademarks of Bunn-O-Matic Corporation.

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29319 091203

USER NOTICES

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.

# 00986.0000

# 00656.0000

# 00658.0000

! WARNING

DO NOT OVERLOAD CIRCUIT. ALWAYS ELECTRICALLY GROUND THE CHASSIS OR ADAPTOR PLUG. DO NOT DEFORM PLUG OR CORD. FOLLOW NATIONAL AND LOCAL ELECTRICAL CODES. KEEP COMBUSTIBLES AWAY.

FAILURE TO COMPLY RISKS EQUIPMENT

DAMAGE, FIRE OR SHOCK HAZARD.

READ THE ENTIRE

OPERATING MANUAL BEFORE

USING THIS PRODUCT

# 12364.0000

# 10044.0000

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29319 041599

ELECTRICAL REQUIREMENTS

CAUTION - The brewer must be disconnected from the power source until specified in

L2 RED

WHITE

NEUTRAL

L1 BLACK

120V.A.C.

208 or 240V.A.C.

120V.A.C.

One circuit models require one 3-wire, grounded service rated 120/208

or 120/240 volts ac, 40 amp, single phase, 60 Hz.

Two circuit models require two 3-wire, grounded service rated 120/208

or 120/240 volts ac, 20 amp, single phase, 60 Hz.

Proceed as follows:

Initial Set-Up.

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. Remove the front panel beneath the sprayhead.

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

5. Connect the brewer to the power source and verify the voltage at the terminal block before proceeding.

Replace the front panel.

6. If plumbing is to be hooked up later be sure the brewer is disconnected from the power source. If plumbing

has been hooked up, the brewer is ready for Initial Set-Up.

PLUMBING REQUIREMENTS

These brewers must be connected to a cold water system with operating pressure between 5 and 90 psi (34.5 and 620 kPa) for CDBC models and 20 and 90 psi (138 and 620 kPa) for CEZ models from a 1⁄2" or larger supply line. A shut-off valve should be installed in the line before the brewer. Install a regulator in the line when pressure is greater than 90 psi (620 kPa) to reduce it to 50 psi (345 kPa). The water inlet fitting is 3⁄8" flare. Bunn-O-Matic does not recommend the use of a reverse-osmosis or deionized water supply to this equipment.

NOTE - Bunn-O-Matic recommends 3⁄8" copper tubing from a 1⁄2" or larger 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 Basic Plumbing Code of the

Building Officials and Code Administrators International, Inc. (BOCA)

and the Food Service Sanitation Manual of the Food and Drug Administration (FDA).

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.

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29319 091203

OPERATING CONTROLS

Model CEZ TWIN

ON/OFF BREW FRONT-SIDE-REAR ON/OFF BREW FRONT-SIDE-REAR

ON/OFF SWITCH

Placing the "ON/OFF" switch in the "ON" upper position supplies power to the brew station warmer, enables the brew circuit, and energizes the tank refill circuit. Placing the switch in the "OFF" lower position stops tank refilling, brewing and deenergizes the brew station warmer. Stopping a brew cycle after it has been started will not stop the flow of water into the decanter until the funnel is empty.

NOTE – Hot water will be available at the faucet in a limited amount when the switch is in the "OFF" position because the tank will not refill.

BREW 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.

ADDITIONAL WARMER SWITCHES

Placing any additional warmer switch in the "ON" upper position supplies power to the associated warmer.

READY INDICATOR

This indicator glows when the preselected brew water temperature has been achieved.

Page 5

BREW SWITCH

Momentarily pressing and releasing the switch starts a brew cycle when the "ON/OFF" indicator is glowing.

NOTE – The "ON/OFF" indicator must be glowing to initiate and complete a brew cycle.

ADDITIONAL WARMER SWITCHES

Pressing any additional warmer switch so the indicator is glowing, supplies power to the associated warmer.

READY INDICATOR

This indicator glows when the preset temperature has been achieved. The word "NOT" above "READY" will glow

in all other instances.

TEMPERATURE INDICATORS (Feature disabled from the factory – refer to page 8.)

The indicator glows to communicate the brew water temperature. Two indicators will glow when the

temperature is between them.

INITIAL SET-UP

1. Insert an empty funnel into the funnel rails of one of the brew stations.

2. Place an empty decanter under the funnel.

3. Connect the brewer to the power source.

4. Model CDBC – Press the "ON/OFF" switch (indicator glowing). Model CEZ – 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 approximately twenty minutes for the water in the tank to heat to the proper temperature.

7. Place a small vessel beneath the faucet and open the faucet handle. Release it when you hear water once again flowing into the tank.

8. Model CDBC – With the "ON/OFF" switch still in the "ON" position (indicator glowing), momentarily press and release the "BREW" switch. Model CEZ – With the "ON/OFF" switch still in the "ON" (upper position), momentarily press and release the "BREW" switch.

9. Allow the cycle to finish and measure the amount of water in the decanter. It should be 64 ounces ± 2. Refer to the adjustments section of this manual should the volume need to be increased or decreased.

NOTE: Repeat steps 1 through 9 for the other brew station.

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 empty decanter beneath the funnel.

5. Model CDBC – Press the "ON/OFF" switch (indicator glowing), then momentarily press and release the "BREW" switch. Model CEZ – Place the "ON/OFF" switch in the "ON" (upper position), then momentarily press and release the "BREW" 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.

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29319 041599

CEZ ADJUSTMENTS & OPTIONAL SETTINGS

Page 7

CDBC ADJUSTMENTS & OPTIONAL SETTINGS

HIDDEN

SWITCH

HIDDEN

SWITCH

P1871

NOTE: The following adjustments must be performed for each Brew Station.

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 temporary function change of this switch. Repeatedly press and release the "ON/OFF" switch until one of the bank of temperature indicators shows the approximate desired temperature. When two indicators are glowing, the temperature is approximately the number between them.

Displaying Brew Temperature

The brewer is factory set with the temperature 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 temperature indicators will glow. Release both switches. Pressing and releasing the "ON/OFF" switch will toggle between turning the entire bank of temperature indicators on-or-off, signifying the "ON" or "OFF" condition of this display. Wait for a few seconds, the brewer will maintain 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 attempt 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 momentarily press the "BREW" switch.

Adjusting Automatic Warmer Shut-Off

The brewer is factory set with this feature disabled. The automatic warmer shut-off deenergizes all warmers after a predetermined time period after the most recent brew cycle. To change the setting, press and hold the "BREW" switch and the "HIDDEN" switch beneath the "®" for five seconds, the entire bank of temperature indicators will flash on-and-off. Release both switches. Pressing and releasing the "BREW" switch will select the number of temperature indicators from none to five. When no indicators are glowing, this feature is disabled and all warmers will be controlled only by their respective switches. When one to five indicators are glowing, it indicates the approximate number of hours of delay before all warmers will be automatically deenergized after the most recent brew cycle.

IMPORTANT: The tank must be full and refill solenoid shut off prior to making these adjustments.

Sprayhead must be installed while making these adjustments.

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29319 030101

Adjusting 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 empty funnel in the funnel rails and an empty decanter or graduated vessel beneath the funnel.

2. Press the "ON/OFF" switch (indicator glowing).

3. Press and hold the brew start button until you hear the brew solenoid click on-and-off three times (approximately 10 seconds). Release the button.

4. Allow the cycle to continue until the desired amount of water is dispensed and then turn "OFF" the brewer.

The brewer is now set to dispense this amount of water for each subsequent brew cycle.

To increase the amount of water for each brew cycle place an empty funnel in the funnel rails and an empty

decanter 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 times (approximately 10 seconds), then release the "BREW" switch. Momentarily press and release the "BREW" switch once for each ounce (approximate) of water to be added to the prior setting and allow the brew cycle to finish.

To decrease the amount of water for each brew cycle place an empty funnel in the funnel rails and an empty

decanter or graduated vessel beneath the funnel. Press the "ON/OFF" switch. Momentarily press and release the "BREW" switch once for each ounce (approximate) of water to be removed from the existing setting. Press and hold the "BREW" switch until you hear the solenoid click on-and-off three times (approximately 10 seconds), then release the "BREW" switch and allow the cycle to finish.

WATER SENSING THRESHOLD ADJUSTMENT PROCEDURE (CDBC TWIN & CDBCF TWIN)

1. Make sure the tank is full of water to be used for calibration. The water must be in contact with the refill probe.

2. Unplug the brewer from the power source, then press and hold the BREW button while power is reapplied.

3. Continue pressing the BREW button until the READY indicator begins to flash. Release the BREW button and then press it again momentarily.

4. The new calibration is automatically completed within a few seconds. If the water is too pure for use with the brewer, the READY indicator will flash very rapidly and the old calibration will be retained.

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29319 091203

PULSE BREW SETUP PROCEDURE (CDBC TWIN & CDBCF TWIN)

The pulse brew parameters (initial fill time, off times, and remaining on times) are entered using the following setby-example process.

1. First set the brew volume using the standard procedure in

2. Position an empty container under the sprayhead. Allow the tank to finish refilling. Make sure that the READY lamp is on, or that the BREW LOCKOUT function is turned off.

3. Press and hold the OFF/ON button. The brew valve will turn on after 10 seconds. Release the button. This begins the initial on-time setting. When the spray has continued for the desired time, momentarily press the OFF/ON button.

4. The spray is now stopped and the off time setting has begun. Press the OFF/ON button momentarily to end the off time.

5. The spray is now on again and the remaining on time setting has begun. Press the OFF/ON button momentarily at the end of the desired remaining on time.

6. The setup is now complete and the parameters are stored in memory. The spray will continue the off and on cycles until the brew volume of step 1 is complete. Pressing the OFF/ON button again will terminate the brewing cycle, with the parameters stored in memory.

7. If only a preinfusion is desired, i.e. an initial on time followed by one off period, use the same procedure, but stop after step 4 and allow the brew to finish the volume set in step 1. This will store the initial on time and off time in memory.

Brew Volume Setup.

Procedure for Disabling Pulse Brew or Preinfusion:

1. Position an empty container under the sprayhead. Allow the tank to finish refilling. Make sure that the READY lamp is on, or that the BREW LOCKOUT function is turned off.

2. Press and hold the OFF/ON button. The brew valve will turn on after 10 seconds. Release the button.

3. Allow the spray to continue and press no buttons until spray stops. The pulse and preinfusion functions are now disabled.

NOTE: When the brewer has been set up for pulse or preinfusion, the adjustment of brew volume is done the same as always and has no effect on the pulse brew parameters. The pulsing is temporarily disabled while adjusting the brew volume and automatically returns during normal brewing.

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29319 091203

TROUBLESHOOTING

A troubleshooting guide is provided to suggest probable causes and remedies for the most likely problems encountered. If the problem remains after exhausting the troubleshooting steps, contact the Bunn-O-Matic Technical Service Department.

• Inspection, testing, and repair of electrical equipment should be performed only by qualified service 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 fittings are tightened or loosened. This will help

to avoid twists and kinks in the tubing.

• Make certain that all plumbing connections are sealed and electrical connections tight and isolated.

• This brewer is heated at all times. Keep away from combustibles.

WARNING –•Exercise extreme caution when servicing electrical equipment.

• Unplug the brewer when servicing, except when electrical tests are specified.

• Follow recommended service procedures.

• Replace all protective shields or safety notices.

Before troubleshooting this brewer, check for the following:

A. Control Boards (CDBC TWIN)

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 important for proper operation.

B. Control Boards (CEZ TWIN)

Locate J6 connector on control board. If jumper 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 jumper 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 bottom side of the control board. Pin 1 of connector J6 is marked by a square solder pad on the foil side of the board and pins 2,3 & 4 are marked by a round solder pad.

C. Control Boards (CDBC TWIN & CEZ TWIN)

Make sure before servicing brewer that voltage is present at control board.

On CDBC TWIN models, press any warmer switch or observe if any indicator lights are 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 terminal block (black and white). Correct the problem and retest before proceeding with testing.

On CEZ TWIN models, 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 terminal block (black and white). Correct the problem and retest before proceeding with testing.

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29319 091203

TROUBLESHOOTING (cont.)

REFILL CIRCUIT

PROBLEM

Will not fill or refill

PROBABLE CAUSE REMEDY

1. Power off to brewer (CDBC & CEZ)

2. Water shut off (CDBC & CEZ)

3. Display flashing (CDBC) or ready light flashing (CEZ)

Press warmer switches on control panel to determine if power is ON.

Make sure water is ON.

Brewer has shut down due to malfunction (See Diagnostic Chart in manual, Page 20, or under top lid of brewer).

4. ON/OFF Switch (CDBC & CEZ)

Make sure ON/OFF Switch is "ON" and indicator is lit.

5. Lime build up on Probe (CDBC & CEZ)

Remove the Probe and check for lime deposit on tip. Clean and reinstall.

6. Refill Valve or Control Board (CDBC & CEZ)

Disconnect the brewer from the power source and remove wires from refill valve coil. Check for continuity across the terminals of the solenoid coil. If continuity is not present, replace the refill valve (See page 31). If continuity is present, the coil may 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 voltmeter to the terminals 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 terminals. If voltage is not present, refer to the wiring diagrams and check the wiring harness.

Fill or refill does not shut "OFF" (ON/OFF Switch "ON")

7. Water is too conductive for proper operation when using the factory setting of sensing threshold. (CDBC)

1. Lime build up on probe (CDBC & CEZ)

Page 12

Reset the

Adjustment Procedures

Water Sensing Threshold

on page 9.

Remove Probe and check for lime deposits on tip. Clean and reinstall.

29319 091203

TROUBLESHOOTING (cont.)

REFILL CIRCUIT (cont.)

PROBLEM

PROBABLE CAUSE REMEDY

2a. Water Level Probe Sensing System (CDBC)

A) Disconnect the brewer from the power source. Disconnect the J3 connector from the control board. Check for continuity from the nut on top of the level probe to pin 1 of the plug, continuity should be present. Pull the temperature probe up about an inch from the grommet. Check for continuity from the outside surface of the temperature probe and pin 4 of the plug, continuity should be present. Connect the J3 plug to the control board and proceed to step 3.

2b. Water Level Probe Sensing System (CEZ)

B) Disconnect the brewer from the power source. Disconnect the J5 connector from the control board. Check for continuity from the nut on top of the level probe to pin 5 of the plug, continuity should be present. Pull the temperature probe up about an inch from the grommet. Check for continuity from the outside surface of the temperature probe and pin 2 of the plug, continuity should be present. Connect the J5 plug to the control board and proceed to step 3.

Fill or refill does not shut "OFF" (ON/OFF Switch "OFF")

3. Refill valve or control board (CDBC & CEZ)

4. Water is too conductive for proper operation when using the factory setting of sensing threshold.

1. Refill valve or control board (CDBC & CEZ)

Page 13

Press ON/OFF switch to "ON" (Indicator lamp should be lit). If water continuously flows out of air vent tube, disconnect the brewer from the power source. If water flow stops, replace the control board. If water flow does not stop, repair or replace the refill sol-enoid.(See page

31)

Reset the

Adjustment Procedures

Water Sensing Threshold

on page 9.

If water continuously flows out of air vent tube, disconnect the brewer from the power source. If water flow does not stop, repair or replace the refill solenoid. If the valve closes when power is removed, replace the control board. (See pages 22 &

23)

29319 091203

TROUBLESHOOTING (cont.)

HEATING CIRCUIT

PROBLEM

Water does not heat to proper temperature

IMPORTANT: Make sure no temperature tests are taken before the ready light is "ON". Tank temperature must be stabilized before readings are taken.

PROBABLE CAUSE

1. Display flashing (CDBC) or ready light flashing (CEZ)

2. Water not touching temperature probe

3a. Dry Plug In Probe Sensing System (CDBC)

REMEDY

Brewer has shut down due to malfunction (See Diagnostic Chart in manual, Page 20, or under top lid).

Remove probe and grommet. Look into hole on tank lid. Water must be within one inch from top of tank.

A) Disconnect the brewer from the power source. Disconnect the J3 connector from the control board. Check for continuity from the tank mounting screw where the green wire mounts, to pin 2 of the plug, continuity should be present. Pull the temperature probe up about an inch from the grommet. Check for continuity from the outside surface of the temperature probe and pin 4 of the plug, continuity should be present. Connect the J3 plug to the control board and proceed to step 4a.

3b. Dry Plug In Probe Sensing System (CEZ)

Page 14

B) Disconnect the brewer from the power source. Disconnect the J5 connector from the control board. Check for continuity from the tank mounting screw where the green wire mounts, to pin 5 of the plug, continuity should be present. Pull the temperature probe up about an inch from the grommet. Check for continuity from the outside surface of the temperature probe and pin 2 of the plug, continuity should be present. Connect the J5 plug to the control board and proceed to step 4b.

29319 091203

TROUBLESHOOTING (cont.)

HEATING CIRCUIT

PROBLEM

Water does not heat to proper temperature (cont.)

IMPORTANT: Make sure no temperature tests are taken before the ready light is "ON". Tank temperature must be stabilized before readings are taken.

PROBABLE CAUSE

4a. Temperature Probe (CDBC)

4b. Temperature Probe (CEZ)

REMEDY

A) Remove the probe from the grommet and submerge in a water bath of approximately 70°F(21°C). Connect an ohmmeter 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 reading should be 9.3k ± 2k OHMS. If the probe is within these parameters, reconnect the J3 plug to the control board.

B) Remove the probe from the grommet and submerge in a water

bath of approximately 70°F(21°C). Connect an ohmmeter 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 reading should be 9.3k ± 2k OHMS. If the probe is within these parameters, reconnect the J5 plug to the control board.

Spitting or excessive steaming

5. Limit Thermostat (CDBC & CEZ)

6. Tank Heater (CDBC & CEZ)

1. Lime build up on temperature probe, tank or tank heater

Page 15

Disconnect the brewer from the power source. Check for continuity across the limit thermostat terminals. Continuity should be present. If not replace the limit thermostat.(See page 28)

Disconnect the brewer from the power source. Check for continuity between the white terminal of the terminal 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 problem, then replace the tank heater if no wiring problem is found.(See page 29)

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

29319 091203

TROUBLESHOOTING (cont.)

HEATING CIRCUIT

PROBLEM

Spitting or excessive steaming (cont.)

PROBABLE CAUSE

2a. Temperature Probe (CDBC)

2b. Temperature Probe (CEZ)

REMEDY

A) Remove the probe from the grommet and submerge in a water bath of approximately 70°F(21°C). Connect an ohmmeter to pins 3 and 4 of the J3 connector. At 60°F(16°C) the reading should be

B) Remove the probe from the grommet and submerge in a water bath of approximately 70°F(21°C). Connect an ohmmeter to pins 2 and 3 of the J5 connector. At 60°F(16°C) the reading should be

Brewer is making unusual noises

3. Control Board (CDBC & CEZ)

1. Plumbing lines

2. Water supply

3. Lime build up

Page 16

Set the temperature to 200°F (95°C). Let tank temperature stabilize. If temperature in tank is above temperature setting by more than 7°F, replace the control board.(See pages 22 & 23)

Plumbing lines should not rest on the counter top.

The brewer must be connected to a cold water supply.

Remove the tank lid and clean inside of tank with a deliming agent, if necessary.

29319 091203

TROUBLESHOOTING (cont.)

BREWING CIRCUIT

PROBLEM

Brew cycle will not start

PROBABLE CAUSE REMEDY

1. Display flashing (CDBC) or ready light flashing (CEZ)

Brewer has shut down due to malfunction (See Diagnostic Chart in manual, Page 20, or under top lid of brewer).

2. No water

Water lines and valves to the brewer must be open.

3. No power or incorrect voltage to the brewer

Check for voltage across the black and white terminals at the terminal block.

4. ON/OFF switch not in the "ON"

The indicator lamp must be lit

position

5. Low water temperature (Brew lockout is enabled)

Allow brewer to heat until ready lamp is lit, or disable the brew lockout feature. (See page 7 or 8)

6. Water not touching refill probe inside tank

7. Switch panel (CDBC)

Press ON/OFF switch (indicator must be lit). Brewer will refill until water touches probe inside tank. Water must be in contact with refill probe before brew cycle will start.

Disconnect the brewer from the power source. Disconnect the ribbon connector from the control board. Check for continuity between 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 continuity is present, replace the switch membrane decal.(See page

24)

Page 17

29319 091203

TROUBLESHOOTING (cont.)

BREWING CIRCUIT (cont.)

PROBLEM

Brew cycle will not start (cont.)

PROBABLE CAUSE REMEDY

8. Control board or dispense valve (CDBC & CEZ)

If the start switch (CEZ) or switch panel (CDBC) is operating properly, proceed as follows. Attach a voltmeter to the terminals of the dispense solenoid. Connect the brewer to the power source. Turn on the brewer and press the BREW switch. Voltage should be present at the solenoid terminals. If voltage is not present, refer to the wiring diagrams and check the wiring harness. If voltage is present, check for continuity across the terminals of the solenoid coil. If continuity is not present, replace the solenoid (See page 27). If continuity is present, the valve may be stuck closed.

Consistently low beverage level in the dispenser or beverage overflows dispenser

1. Brew volume (CDBC & CEZ)

2. Lime build up

3. Dispense Valve

Set up brewer according to instructions in section

Adjustments

Brew Volumes. (See pages 7 or 8)

Using a stop watch or second hand, time the length of the brew cycle. Record this time inside the top lid. If service is ever needed again, use the time as reference to determine if time has changed.

Inspect the dispense valve and sprayhead for excessive lime deposits. Delime as required.

Remove dispense valve and clear any obstructions. Rebuild or replace valve if necessary. (See page

27)

Page 18

29319 091203

TROUBLESHOOTING (cont.)

BREWING CIRCUIT (cont.)

PROBLEM

Dripping from sprayhead

Weak beverage

PROBABLE CAUSE REMEDY

1. Lime build up

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

2. Dispense valve

Remove the dispense valve and clear any obstructions. Rebuild or replace the valve if necessary.(See page 27)

1. Sprayhead

A six-hole stainless steel sprayhead must be used for proper extraction.

2. Water temperature

Place an empty brew funnel on an empty decanter beneath the sprayhead. Initiate brew cycle and check the water temperature immediately below the sprayhead with a thermometer. The reading must not be less than 195°F(91°C). Adjust the temperature setting to increase the water temperature. Refer to

Initial Set-up

instructions.

3. Filter type

4. Coffee grind

5. Funnel loading

Page 19

BUNN® paper filters must be used for proper extraction.

A fine or drip grind must be used for proper extraction.

The BUNN® paper filter must be centered in the funnel and the bed of grounds leveled by shaking gently.

29319 091203

TROUBLESHOOTING (cont.)

BREWING CIRCUIT (cont.)

PROBLEM

Dry coffee grounds remain in the funnel

Low beverage serving temperature

PROBABLE CAUSE REMEDY

1. Sprayhead

Make sure sprayhead is present and holes are clear and unobstructed. There should be six separate streams of water coming out of the sprayhead.

2. Funnel loading

The BUNN® paper filter must be centered in the funnel and the bed of grounds leveled by shaking gently.

1. Warmer

Disconnect the brewer from the power source. Remove the warmer plate and turn upside down to expose the warmer terminals. Remove the two wires. Check for continuity across the two warmer terminals. If continuity is not present, replace the warmer element (See page 32). If continuity is present, reconnect the wires to the warmer element. Check for voltage at the warmer terminals. Turn the warmer switch "ON". The indicator light will come on. Voltage should be present at the terminals. If not, disconnect power supply and check wiring and switch.

Page 20

29319 091203

DIAGNOSTICS

Intermittent flashing of the READY indicator (Model CEZ) or the bank of temperature indicators (Model CDBC) indicates that a fault exists. Count the number of flashes between pauses and use this chart as a guide to investigating the fault.

FLASHES CAUSE THINGS TO CHECK

1 Dry Plug - In Fault - Water Pressure (is water shut off?)

Sheath of temperature probe dry for 10 minutes after power-up Temperature probe wiring

Fill valve wiring, function, & strainer Green wire between tank and circuit board

2 Low Tank Level Fault - Water pressure (is water shut off?)

Level probe dry for 7 minutes after fill valve is energized Shorting pin on J6 connector of control board not

on correct set of pins (CEZ boards only). See page 7 Level probe wiring Temperature probe wiring Fill valve wiring, function, & strainer

3 Low Water Temperature Fault - Tank heater wiring & function

Sensor in tank is calling for heat for 30 minutes or more Temperature probe wiring

4 Tank Sensor Disagreement - Temperature probe wiring

Level probe detects water, but dry plug-in probe dry Level probe wiring

Green wire between tank and circuit board

5 Temp Sensor Out-of-Range - High Sensor not connected to circuit board

6 Temp Sensor Out-of-Range - Low Sensor wires shorted together or to chassis

Page 21

29319 091203

R E T

A C

S I

HED

ACKED

MPTY E

CRATC

HEN

LEC

BOILED DRY

N HIGH FLAM

HEATED W

SED

D O

XPO

USE

R E

MENTS

TIO

ORA

S I

N O

UNN-O-MATIC CORP

1985

T E R

U L

I A F

PN: 65

CAUTION :

CAUTION :CAUTION :

R E T

N A C

S I

F I

. CRACKED

AME

FL . SCRATCHED . BOILED DRY

SED ELECTRIC . HEATED WHEN EMPTY . USED ON HIGH

R EXPO

. O

EMENTS

N I

ATION

POR

S I

N O

O-MATIC C

NN-

1985 BU

T E R

L I A F

: 658 PN

CAUTION :

Page 22

CAUTION :

Page 23

: N

IO T

U A

Page 24

SERVICE (cont.)

SWITCH PANEL - Model CDBC

TIO

DISCARD DECANTER

IF:

. S

P X

S U .

IO T

O P OR

C IC

MAT

-O-

N UN B

FUNNEL CONTENTS ARE HOT

FAILURE TO COMPLY RISKS INJURY

58 19

: 6

CAUTION :

CAUTION :CAUTION :

FIG. 4 SWITCH PANELS - CDBC

Location:

The Switch Panels are located on the front of the

hood.

P1875

Removal and Replacement:

1. Disconnect the 11-pin connector to the switch panel from the control board.

2. Remove the four #6 screws, nylon washers and the two #4 screws securing the control board to the end cap assembly and set aside.

3. Gently pry the switch panel from the end cap assembly.

4. Remove any adhesive that remains on the end cap.

5. Remove the adhesive backing from the new switch panel. Insert the ribbon connector through the slot in the end cap and apply the switch panel to the end cap.

6. Install the control board to the back side of the end cap using the four #6 screws, nylon washers and the two #4 screws to the end cap assembly. NOTE: The four nylon washers must be installed under the heads of the four #6 screws to prevent possible shorting of the control board circuits.

7. Reconnect the 11-pin connector from the switch panel to the control board making sure every pin on the control board is inserted into the ribbon cable plug.

Test Procedures:

The test procedures for the switch panels and the control boards will vary depending upon the problems experienced by the brewer. Refer to the troubleshooting guide beginning on page 10. The troubleshooting guide is divided into three sections, Refill Circuit, Heating Circuit and Brewing Circuit.

Page 25

29319 091203

Page 26

N :

UTIO

Page 27

Page 28

SERVICE (cont.)

LIMIT THERMOSTAT

M R T

M TR

FIG. 11 LIMIT THERMOSTATS

Removal and Replacement:

1. Remove the black and blue 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.

1 M

M R T

FRO

TER

AN C E

D D

CAUTION

DISC

IF:

. S

. B

. U

T N

. O

JUR

S IN

ISK

TEN

O C

CAUTION :

-M

PLY

-O

EL C

U B 85

RE HO

FUN

TO C E

ILUR

8 65 : N

/LOW

TY P

TIO A R

O P

CAUTION :

-R

T-SIDE

EAR

IDE-R

T-S

FRO

START

S R E

M R A

P1878

4. Refer to FIG. 12 when reconnecting the wires.

BLU from Control Board

BLK from Terminal Block

Location:

The limit thermostats are located inside the front

access panel on the front side of the tanks.

Test Procedures:

1. Disconnect the brewer from the power source.

2. Disconnect the blue and black wires from the limit thermostat.

3. With an ohmmeter, check for continuity across the limit thermostat terminals.

If continuity is present as described, the limit thermostat is operating properly. If continuity is not present as described, replace the limit thermostat.

P1800

FIG. 12 LIMIT THERMOSTAT WIRING

Page 29

29319 091203

Page 30

SERVICE (cont.)

TANK HEATERS (Cont.)

17. Install tank assembly onto mounting brackets and secure in place with four #8-32 nuts.

18. Install tank lid and secure in place with eight #8-32 nuts.

19. Connect the two white wires of the tank warmer blanket.

20. Connect the limit thermostat to the front of the tank assembly.

21. Connect the green wire to the tank mounting bracket using #8-32 nut.

22. Connect the pink wire to the level probe.

23. Insert the temperature probe through the grommet in the tank lid.

24. Install the elbow fitting of the vent hose into the grommet in the tank lid.

25. If installing left tank, on brewers with faucet, connect the outlet water line of the faucet to the side of the tank and secure with clamp.

26. Connect the water supply tube from the solenoid to the bottom of the tank and secure with clamp.

27. Connect the water supply tube from the dispense valve to the side of the tank and secure with clamp.

28. Refer to FIG. 14 when reconnecting the tank heater wires.

29. Install access panels and covers and refer to

Set-up

for refill and operation.

Initial

P1856

Page 31

ION :

Page 32

CAUTION :

CAUTION :CAUTION :

Page 33

GRN

BLK

BLK-14

WHI

WHI-14

BLK-14

RED-14 (MODEL 35)

BREWERS WITH 1 POWER CORD ONLY

L1 N L2

120/208V AC 3 WIRE

120/240V AC 3 WIRE

SINGLE PHASE

SCHEMATIC WIRING DIAGRAM CEZ TWIN 0/6 (LEFT)

SCHEMATIC WIRING DIAGRAM CEZ TWIN 0/6 (RIGHT)

P1, P2, & P3 ARE PINS OF A

POLARIZED THREE-PIN

CONNECTOR.

WHI

SOL

WHI

START SWITCH

TANK HEATER

BLU-14

"KEEP WARM" HEATER

WHI

LIMIT

THERMOSTAT

BLK

WHI/RED

WHI

SOL

REFILL

DISPENSE

TRM-1

TRM-2

J7-1

J7-2

J1-1

J1-8

J5-1

J5-6

COM

N.O.

BLK

BLK-14

BLK

BLK-14

BLK

WHI/GRN

WHI/BLU

WHI/YEL

WHI/ORA

PNK

WHI

GRN

COUNTER (OPTIONAL)

PNK

GRY

t°

BLK

BLK-14

WHI

120/208V AC 3 WIRE

120/240V AC 3 WIRE

SINGLE PHASE

P1, P2, & P3 ARE PINS OF A

POLARIZED THREE-PIN

CONNECTOR.

WHI

SOL

WHI

START SWITCH

TANK HEATER

BLU-14

"KEEP WARM" HEATER

WHI

BREW STATION WARMERBREW STATION WARMER

WHI

LIMIT

THERMOSTAT

BLK

WHI/RED

WHI

SOL

REFILL

DISPENSE

TRM-1

TRM-2

J7-1

J7-2

J1-1

J1-8

J5-1

J5-6

COM

N.O.

BLK

BLK-14

BLK

BLK-14

BLK

WHI/GRN

WHI/BLU

WHI/YEL

WHI/ORA

PNK

WHI

GRN

COUNTER (OPTIONAL)

PNK

GRY

t°

FRONT WARMER

WHI

BRN/BLK

VIO

WHI

REAR WARMER

WHI

BRN/BLK

VIO

FRONT WARMER

WHI

BRN/BLK

VIO

WHI

REAR WARMER

BRN/BLK

VIO

WHI/RED

RED-14 (MODEL 35) RED-14 (MODEL 35)

Page 34

29319 091203

SCHEMATIC WIRING DIAGRAM CDBC TWIN 0/6 (LEFT)

TANK HEATER

GRN

RED-14 (MODEL 35)

BLK

BLK-14

SCHEMATIC WIRING DIAGRAM CDBC TWIN 0/6 (RIGHT)

WHI

WHI-14

BLK-14

RED-14 (MODEL 35)

BREWERS WITH 1 POWER CORD ONLY

L1 N L2

P1, P2, &

P3 ARE

PINS OF A

POLARIZED

THREE-PIN

CONNECTOR.

SOL

BLU-14

"KEEP WARM" HEATER

WHI

BREW STATION WARMER

(CONTROLLED BY ON/OFF SW)

LIMIT

THERMOSTAT

WHI/RED

WHI

REAR WARMER

FRONT WARMER

WHI

SOL

REFILL

DISPENSE

J1-1

J1-2

J1-1

J1-5

J1-10

COM

N.O.

BLK

BLK-14

BLK

WHI/GRN

WHI/BLU

COUNTER

(OPTIONAL)

120/208V AC 3 WIRE

120/240V AC 3 WIRE

SINGLE PHASE

120/208V AC 3 WIRE

120/240V AC 3 WIRE

SINGLE PHASE

YEL

WHI/VIO

BLK

WHI

YEL YEL

LEFT CONTROL PANEL ASSY

J2-1

J2-6

J2-11

BREW SW

STATIC

SHIELD

ON/OFF SW

HIDDEN SW

LT FRNT SW

LT REAR SW

J3-1

J3-4

BLK

PNK

WHI

GRN

LEVEL

PROBE

t°

TANK HEATER

BLK

BLK-14

WHI

P1, P2, &

P3 ARE

PINS OF A

POLARIZED

THREE-PIN

CONNECTOR.

SOL

FRONT WARMER

BRN/BLK

VIO

WHI

REAR WARMER

BLU-14

"KEEP WARM" HEATER

WHI

BREW STATION WARMER

(CONTROLLED BY ON/OFF SW)

LIMIT

THERMOSTAT

BRN/BLK

VIO

WHI/RED

WHI

SOL

REFILL

DISPENSE

J1-1

J1-2

J1-1

J1-5

J1-10

COM

N.O.

BLK

BLK-14

BRN/BLK

BLK

WHI/GRN

WHI/BLU

COUNTER

(OPTIONAL)

VIO

BLK

WHI

RIGHT CONTROL PANEL ASSY

J2-1

J2-6

J2-11

BREW SW

STATIC

SHIELD

ON/OFF SW

HIDDEN SW

RT REAR SW

RT FRNT SW

J3-1

J3-4

BLK

PNK

WHI

GRN

LEVEL

PROBE

t°

RED-14 (MODEL 35)

Page 35

29319 091203

SCHEMATIC WIRING DIAGRAM CDBC TWIN 2/2 (LEFT)

TANK HEATER

GRN

RED-14 (MODEL 35)

BLK

BLK-14

SCHEMATIC WIRING DIAGRAM CDBC TWIN 2/2 (RIGHT)

WHI

WHI-14

BLK-14

RED-14 (MODEL 35)

BREWERS WITH 1 POWER CORD ONLY

L1 N L2

P1, P2, &

P3 ARE

PINS OF A

POLARIZED

THREE-PIN

CONNECTOR.

SOL

BLU-14

"KEEP WARM" HEATER

WHI

BREW STATION WARMER

(CONTROLLED BY ON/OFF SW)

LIMIT

THERMOSTAT

WHI/RED

WHI

TOP FRONT WARMER

WHI

SOL

REFILL

DISPENSE

J1-1

J1-2

J1-1

J1-5

J1-10

COM

N.O.

BLK

BLK-14

BLK

WHI/GRN

WHI/BLU

COUNTER

(OPTIONAL)

120/208V AC 3 WIRE

120/240V AC 3 WIRE

SINGLE PHASE

120/208V AC 3 WIRE

120/240V AC 3 WIRE

SINGLE PHASE

VIO VIO

BLK

WHI

LEFT CONTROL PANEL ASSY

J2-1

J2-6

J2-11

BREW SW

STATIC

SHIELD

ON/OFF SW

HIDDEN SW

TOP FRNT SW

J3-1

J3-4

BLK

PNK

WHI

GRN

LEVEL

PROBE

t°

TANK HEATER

BLK

BLK-14

WHI

P1, P2, &

P3 ARE

PINS OF A

POLARIZED

THREE-PIN

CONNECTOR.

SOL

BLU-14

"KEEP WARM" HEATER

WHI

BREW STATION WARMER

(CONTROLLED BY ON/OFF SW)

LIMIT

THERMOSTAT

WHI/RED

WHI

SOL

REFILL

DISPENSE

J1-1

J1-2

J1-1

J1-5

J1-10

COM

N.O.

BLK

BLK-14

BLK

WHI/GRN

WHI/BLU

COUNTER

(OPTIONAL)

VIO

BLK

WHI

RIGHT CONTROL PANEL ASSY

J2-1

J2-6

J2-11

BREW SW

STATIC

SHIELD

ON/OFF SW

HIDDEN SW

J3-1

J3-4

BLK

PNK

WHI

GRN

LEVEL

PROBE

t°

RED-14 (MODEL 35)

TOP FRONT WARMER

VIO

Page 36

29319 091203

Bunn CDBC TWIN User Manual

Specifications and Main Features

Frequently Asked Questions

User Manual