BUNN ®
INTRODUCTION This equipment will automatically brew a half-gallon batch of coffee into an awaiting decanter at the press of a button. A hot water faucet is 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 ..............................................................................
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 ! 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.
ELECTRICAL REQUIREMENTS CAUTION - The brewer must be disconnected from 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 amp, single phase, 60 Hz. L2 RED WHITE NEUTRAL L1 BLACK WHITE 120V.A.C. 120V.A.C. 208 or 240V.A.C. NEUTRAL 120V.A.C. L1 BLACK Model 20 requires 2-wire, grounded service rated 120 volts ac, 20 amp, single phase, 60 Hz.
OPERATING CONTROLS Model CEZ 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 and 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.
OPERATING CONTROLS (cont.) ADDITIONAL WARMER SWITCHES (CDBC only) Pressing any additional warmer switch so that 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.
POUR-OVER FEATURE If the brewer is equipped with a pour-over feature, follow the instructions below. 1. Remove the thumbscrew and pour-in lid from the top cover of the brewer and set aside. 2. Insert a BUNN® filter into the funnel. 3. Pour fresh coffee grounds into the filter and level the bed of grounds by gently shaking. 4. Slide the funnel into the funnel rails. 5. Place an empty decanter beneath the funnel. 6.
CEZ ADJUSTMENTS & OPTIONAL SETTINGS Page 8
CDBC ADJUSTMENTS & OPTIONAL SETTINGS HIDDEN SWITCH P1866 Setting Brew Temperature The brewer is factory set to brew at 200°F (93˚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.
ADJUSTMENTS & OPTIONAL SETTINGS (cont.) 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/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 times (approximately 5 seconds). Release the button. 4.
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.
TROUBLESHOOTING (cont.) REFILL CIRCUIT PROBLEM PROBABLE CAUSE REMEDY Will not fill or refill 1. Power off to brewer (all models) Press warmer switches on control panel to determine if power is ON. 2. Water shut off (all models) Make sure water is ON. 3. Display flashing (CDBC) or ready light flashing (CEZ) Brewer has shut down due to malfunction (See Diagnostic Chart in manual, Page 19, or under top lid of brewer). 4.
TROUBLESHOOTING (cont.) REFILL CIRCUIT (cont.) PROBLEM PROBABLE CAUSE REMEDY Fill or refill does not shut "OFF" (ON/OFF Switch "ON") 1. Lime build up on probe (all models) Remove Probe and check for lime deposits on tip. Clean and reinstall. 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.
TROUBLESHOOTING (cont.) HEATING CIRCUIT PROBLEM PROBABLE CAUSE REMEDY Water does not heat to proper temperature 1. Display flashing (CDBC) or ready light flashing (CEZ) Brewer has shut down due to malfunction (See Diagnostic Chart in manual, Page 19, or under top lid). 2. Water not touching temperature probe Remove probe and grommet. Look into hole on tank lid. Water must be within one inch from top of tank. 3a. Dry Plug In Probe Sensing System (CDBC) A) Disconnect the brewer from the power source.
TROUBLESHOOTING (cont.) HEATING CIRCUIT (cont.) PROBLEM Water does not heat to proper temperature (cont.) PROBABLE CAUSE REMEDY 4a. Temperature Probe (CDBC) 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.
TROUBLESHOOTING (cont.) HEATING CIRCUIT (cont.) PROBLEM PROBABLE CAUSE REMEDY Spitting or excessive steaming (cont.) 2a. Temperature Probe (CDBC) 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°Cº the reading should be 11.8k ± 2k OHMS, and at 80°F(27°C) the reading should be 9.3k ± 2k OHMS.
TROUBLESHOOTING (cont.) BREWING CIRCUIT PROBLEM PROBABLE CAUSE REMEDY Brew cycle will not start 1. Display flashing (CDBC) or ready light flashing (CEZ) Brewer has shut down due to malfunction (See Diagnostic Chart in manual, Page 19, 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.
TROUBLESHOOTING (cont.) BREWING CIRCUIT (cont.) PROBLEM PROBABLE CAUSE REMEDY Brew cycle will not start (cont.) 8. Control board or dispense valve (all models) 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.
TROUBLESHOOTING (cont.) BREWING CIRCUIT (cont.) PROBLEM PROBABLE CAUSE REMEDY Dripping from spray head 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 26) 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.
TROUBLESHOOTING (cont.) BREWING CIRCUIT (cont.) PROBLEM Dry coffee grounds remain in the funnel Low beverage serving temperature PROBABLE CAUSE 1. Sprayhead REMEDY 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.
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.
E H O T ER N IO CANT UT RD DE CA DISCA A R IF: C A U T IO N : W A R M E R S A N D S U R F A C E S ! Page 22
SERVICE (cont.) C A U T IO N : W A R M E R S A N D S U R F A C E S A R E H O T CONTROL BOARD - Model CDBC P1846 Location: The Control Board is located inside the top cover behind the front end cap. Test Procedures: The test procedures for the control board will vary depending upon the problems experienced by the brewer. Refer to the Troubleshooting guide beginning on page 9.
SERVICE (cont.) C A U T IO N : W A R M E R S A N D S U R F A C E S A R E H O T C A U T IO N : W A R M E R S A N D S U R F A C E S A R E H O T CONTROL BOARD - Model CEZ P1847 Location: The Control Board is located inside the trunk behind the front access panel. Test Procedures: The test procedures for the control board will vary depending upon the problems experienced by the brewer. Refer to the Troubleshooting guide beginning on page 9.
SERVICE (cont.) SWITCH PANEL - Model CDBC P1848 FIG. 4 SWITCH PANEL - CDBC Location: The Switch Panel is located in the front of the hood. 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 #4-40 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.
SERVICE (cont.) ON/OFF SWITCHES - Model CEZ 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 remaining wire to the lower terminal. If continuity is not present as described, replace the switch.
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SERVICE (cont.) C A U T IO N : W A R M E R S A N D S U R F A C E S A R E H O T DISPENSE VALVE P1852 Location: The dispense valve is located inside the top cover behind the front end cap. Test Procedures: 1. Disconnect the brewer from the power source. 2. Check the water level in the tank to confirm that it is within 1/2" from the top of the tank. 3. Connect the brewer to the power source.
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SERVICE (cont.) 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. TANK HEATER NOTE- If the tank heater remains unable to heat, remove and inspect heater for cracks in the sheath. P1855 FIG. 13 TANK HEATER Location: The tank heater is located inside the tank and secured to the tank bottom. Test Procedures: 1. Disconnect the brewer from the power supply. 2.
SERVICE (cont.) TANK HEATER (Cont.) 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.
SERVICE (cont.) REFILL VALVE If continuity is not present as described, replace the refill valve. 6. Check the refill 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 refill valve for a" clicking" sound as the coil magnet attracts. 7. Disconnect the brewer from the power source.
SERVICE (cont.) WARMER ELEMENT(S) 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. ! CA UT IO N RD CA DIS IF: ER NT CA DE If continuity is present as described, reconnect the two wires to the warmer element. If continuity is not present as described, replace the warmer element. P1859 FIG.
SCHEMATIC WIRING DIAGRAM CDBC - 15, 20 & 35 L1 N GRN LIMIT THERMOSTAT TANK HEATER BLU-14 WHI-14 (MODELS 15 & 20) RED-14 (MODEL 35) WHI "KEEP WARM" HEATER WHI BREW STATION WARMER WHI/RED (CONTROLLED BY ON/OFF SW) WHI REFILL C O N T R O L J1-1 J1-2 BLU-14 WHI P2 BRN/BLK J1-5 C WHI WHI SOL J1-1 P B O A R D SOL DISPENSE BRN/BLK FRONT WARMER WHI P1 WHI/RED P3 VIO VIO P1, P2, & P3 ARE PINS OF A POLARIZED THREE-PIN CONNECTOR.
SCHEMATIC WIRING DIAGRAM CEZ L1 N GRN LIMIT THERMOSTAT BLK-14 BLU-14 WHI-14 (MODELS 15 & 20) RED-14 (MODEL 35) TANK HEATER BLK-14 "KEEP WARM" HEATER WHI WHI BLK C O N T R O L L2 WHI COUNTER (OPTIONAL) BLK TRM-1 TRM-2 BLK COM BLU-14 N.O.
SCHEMATIC WIRING DIAGRAM CDBCP/CDBCPF - 15, 20 & 35 N L2 L1 W/Flashing Lamp (Freshness) GRN LIMIT THERMOSTAT BLU-14 BLK-14 BLK-14 TANK HEATER WHI-14 (MODELS 15 & 20) RED-14 (MODEL 35) "KEEP WARM" HEATER WHI WHI BLK BREW STATION WARMER WHI/RED (CONTROLLED BY ON/OFF SW) WHI REFILL C O N T R O L RED TRM-1 BLK TRM-2 BLU-14 COM BLK-14 N.O.
