Bunn-O-Matic DUAL, DUAL SH, SINGLE, SINGLE SH Service Manual

DUAL ®&

DUAL ® SH

(Serial # DUAL010000 - Up)

SINGLE ®&

SINGLE ® SH

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8 : 65 PN

(Serial # SNG0005000 - Up)

gal

1⁄

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gal

2 ⁄ 1

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SELECT

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ON / WARMER

STA

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START

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PN: 658

FAILURE TO COMPLY RISKS INJURY

gal

2 ⁄ 1

1 gal

gal

2 ⁄ 1

SELECTO

READY

CAUTION

DISCARD DECANTER

IF:

. CRACKED . SCRATCHED . BOILED DRY . HEATED WHEN EMPTY . USED ON HIGH FLAME . OR EXPOSED ELECTRIC ELEMENTS

-MATIC CORPORATION

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SERVICE & REPAIR MANUAL

BUNN-O-MATIC CORPORATION

POST OFFICE BOX 3227

SPRINGFIELD, ILLINOIS 62708-3227

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

T O H

S ARE E C

FA R U

S D

AN S R

E M

WAR : N

TIO

U A C

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.

392, AutoPOD, AXIOM, BrewLOGIC, BrewMETER, Brew Better Not Bitter, BrewWISE, BrewWIZARD, BUNN Espress, BUNN Family Gourmet, BUNN Gourmet, BUNN Pour-O-Matic, BUNN, BUNN with the stylized red line, BUNNlink, Bunn-OMatic, Bunn-O-Matic, BUNNserve, BUNNSERVE with the stylized wrench design, Cool Froth, DBC, Dr. Brew stylized Dr. design, Dual, Easy Pour, EasyClear, EasyGard, FlavorGard, Gourmet Ice, Gourmet Juice, High Intensity, iMIX, Infusion Series, Intellisteam, My Café, PowerLogic, Quality Beverage Equipment Worldwide, Respect Earth, Respect Earth with the stylized leaf and coffee cherry design, Safety-Fresh, savemycoffee.com, Scale-Pro, Silver Series, Single, Smart Funnel, Smart Hopper, SmartWAVE, Soft Heat, SplashGard, The Mark of Quality in Beverage Equipment Worldwide, ThermoFresh, Titan, A Partner You Can Count On, Air Brew, Air Infusion, Beverage Bar Creator, Beverage Proﬁt Calculator, Brew better, not bitter., BUNNSource, Coffee At Its Best, Cyclonic Heating System, Digital Brewer Control, Nothing Brews Like a BUNN, Pouring Proﬁts, Signature Series, Tea At Its Best, Phase Brew, The Horizontal Red Line, trifecta, Ultra, Velocity Brew are either trademarks or registered trademarks of Bunn-O-Matic Corporation.

Page 2

41976 050511

TROUBLESHOOTING

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

 • Inspection,testing,andrepairofelectricalequipmentshouldbeperformed only by qualied

service personnel.

 • Allelectroniccomponentshave120-240voltacandlowvoltagedcpotentialontheirterminals.

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

 • Intermittentoperationofelectroniccircuitboardsisunlikely.Boardfailurewillnormallybeper-

manent. 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sole-

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

 • Theuseoftwowrenchesisrecommendedwheneverplumbingttingsaretightenedorloosened.

This will help avoid twists and kinks in the tubing.

 • Makecertainthatallplumbingconnectionsaresealedandelectricalconnectionstightandiso-

lated.

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

WARNING

 • Exerciseextremecautionwhenservicingelectricalequipment.  • Disconnectthebrewerfromthepowersourcewhenservicing,exceptwhenelectricaltestsare

speciﬁed.

 • Followrecommendedserviceprocedures.  • Replaceallprotectiveshieldsorsafetynotices.

Problem

Probable Cause

Remedy

Equipment will not operate.

Brew cycle will not start.

1. No power or incorrect voltage.

1. No water

2. Water strainer/ﬂow control (.750 GPM)

(A1) Check the terminal block for 120 volts across the red and white terminals and the black and white terminals on 120V, 120/208 or 120/240 volt brewers.

(A2) Check the terminal block for 200 volts on "B Series" brewers or 240 volts on "A Series" brewers across the red and black terminals.

(B) Check circuit breakers or fuses.

Check plumbing and shut-off valves

(A) Direction of ﬂow arrow must be pointing towards brewer.

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

Page 3

41976 031709

TROUBLESHOOTING (cont.) Problem

Probable Cause

Remedy

Brew cycle will not start (cont.)

Automatic reﬁll will not operate

3. ON/OFF switch

4. Start switch

5. Timer

6. Dispense Valve

7. Control Assembly (Electronic)

8. Server not in place (SH models)

1. No water

2. Water strainer/ﬂow control

Refer to Service - ON/OFF switch for testing procedures.

Refer to Service - Start switch for testing procedures.

Refer to Service - Timer for testing procedures.

Refer to Service - Dispense valve for testing procedures.

Refer to Service - Control assembly for testing procedures.

Make sure server is in place and server present lamp is lit.

Check plumbing and shut-off valves.

(A) Direction of ﬂow arrow must be pointing towards brewer.

3. Solenoid Valve

4. Limit thermostat (Electro/mechanical and Electronic)

5. Overﬂow protection switch

6. (A) Level control board & level probe. (Electro/mechanical controlled)

(B) Electronic controls

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

Refer to Service - Solenoid valve for testing procedures.

Refer to Service - Limit thermostat for testing procedures.

Refer to Service - Overﬂow protection switch for testing procedures.

Refer to Service - Level control board for testing procedures.

Refer to Service - Electronic controls for testing procedures.

Page 4

41976 031709

TROUBLESHOOTING (cont.) Problem

Probable Cause

Remedy

Beverage level will not adjust (Selector switch in any position)

Water ﬂows into tank continuously (On/Off Switch "OFF").

Water ﬂows into tank continuously (ON/OFF switch "ON").

Water from tank is not hot

1. Brew Selector switch

1. Solenoid valve

2A. Level control board and level probe (Electro/mechanical)

2B. Control assembly (Electronic)

3. Overﬂow protection switch

1. Timer

1. Limit thermostat

CAUTION - Do not eliminate or bypass limit thermostat. Use only replacement part #23717.0001

Refer to Service - Selector switch for testing procedures.

Refer to Service - Solenoid valve for testing procedures.

Refer to Service - Level control board for test procedures.

Refer to Service - Control assembly for testing procedures.

Refer to Service - Timer for testing procedures.

Refer to Service - Overﬂow protection switch for testing procedures.

Refer to Service -Limit thermostat for testing procedures.

2A. Control Thermostat (Electro/ mechanical)

2B. Control assembly (Electronic)

3. Contactor (Brewers with Recovery Booster)

4. Tank heaters

5. Triac assembly (Electronic)

Refer to Service - Control Thermostat for testing procedures.

Refer to Service - Control assembly for testing procedure.

Refer to Service - Contactor for testing procedures.

Refer to Service - Tank heaters for testing procedures.

Refer to Service - Triac assembly for testing procedures.

Page 5

41976 031709

TROUBLESHOOTING (cont.)

Problem

Water from tank is not hot (cont.).

Server warmer is not hot.

Spitting or unusual steaming from sprayhead or airvents.

Probable Cause

6. Relay (Brewers with Recovery Booster)

1. ON/OFF switch

2. Warmer element

1A. Control thermostat (Electro/ mechanical)

1B. Control assembly (Electronic)

2. Triac assembly (Electronic)

3. Lime build-up

CAUTION - Tank and tank components should be delimed regularly depending on local water conditions. Excessive mineral build-up on stainless steel surfaces can initiate corrosive reactions resulting in serious leaks.

Remedy

Refer to Service - Relay for testing procedures.

Refer to Service - ON/OFF switch for testing procedures.

Refer to Service - Warmer element for testing procedures.

Refer to Service - Control thermostat for testing procedures.

Refer to Service - Control assembly for testing procedures.

Refer to Service - Triac assembly for testing procedures.

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

Inconsistent beverage level in server.

1. Strainer/ﬂow control

2. Improper water pressure

Page 6

(A) Direction of ﬂow arrow must be pointing towards the brewer.

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

Check operating water pressure to the brewer. It must be between 20 and 90 psi (138 and 620 kPa) .

41976 031709

TROUBLESHOOTING (cont.)

Problem

Inconsistent beverage level in server (cont.).

Consistently high or low beverage level in server.

Dripping from sprayhead.

Water overﬂows ﬁlter.

Probable Cause

3. Dispense valve

1. Timer adjustment

1. Dispense valve

1. Bypass valve

2. Needle Valve

3. Type of paper ﬁlters

Remedy

Refer to Service - Dispense valve for testing procedures.

Adjust the timer as required to achieve the recommended volume for each brew cycle.

Refer to Service - Dispense valve for testing procedures.

Refer to Installation & Operating Guide, Initial Set-Up.

Refer to Installation & Operating Guide, Initial Set-Up

BUNN paper ﬁlters should be used for proper extraction.

Beverage overﬂows server.

Weak beverage.

4. No sprayhead

1. Beverage left in server

2. Timer adjustment

3. Dispense valve

1. Type of paper ﬁlters

2. Coffee

Check sprayhead

The brew cycle should be started only with an empty server under the funnel.

Adjust the timer as required to achieve the recommended volume for each brew cycle. Refer to Service - Timer for testing procedures.

Refer to Service - Dispense valve for testing procedures.

BUNN paper ﬁlters should be used for proper extraction.

A sufﬁcient quantity of fresh drip or regular grind should be used for proper extraction.

Page 7

41976 031709

TROUBLESHOOTING (cont.)

Problem

Weak beverage (cont.)

Probable Cause

3. Sprayhead

4. Funnel loading

5. Water temperature

Remedy

A clean sprayhead should be used to properly wet the bed of ground coffee in the funnel.

The BUNN paper ﬁlter should be centered in the funnel and the bed of ground coffee leveled by gentle shaking.

Empty the server, remove its cover, and place the server on the warmer. Place empty funnel over the server entrance, with ON/OFF switch in the "ON" position press the start switch and release it. Check the water temperature immediately below the sprayhead with a thermometer. The reading should not be less than 195˚F(91˚C).

Brewer is making unusual noises.

1. Solenoid (Inlet)

2. Plumbing lines

3. Water supply

4. Tank Heater(s)

5. Contactor

The nut on back of the solenoid must be tight or it will vibrate during operation

Plumbing lines should not be resting on the counter top.

(A) The brewer must be connected to a cold water line.

(B) Water pressure to the brewer must not be higher than 90 psi (620 kPa). Install a regulator if necessary to lower the working pressure to approximately 50 psi (345 kPa).

Remove and clean lime off tank heater(s).

Check for low voltage

Page 8

41976 031709

TROUBLESHOOTING (cont.)

Problem

Server will not heat

Probable Cause

1. Circuit breaker

2. Receptacle Contacts

3. Relay (Server Power) (Prior to S.N. DUAL026000)

4. Transformer

5. Rectiﬁer

Remedy

A) Check and reset if necessary B) Refer to Service - Circuit breaker for test procedures.

Clean or replace.

Refer to Service - Relay (Soft Heat) for test procedures.

Refer to Service - Transformer for test procedures.

Refer to Service - Rectiﬁer for test procedures.

Page 9

41976 031709

SERVICE

This section provides procedures for testing and replacing various major components used in this brewer should service become necessary. Refer to Troubleshooting for assistance in determining the cause of any problem. Illustrations shown are DUAL brewers with SINGLE brewers similar except where noted.

WARNING - Inspection, testing, and repair of electrical equipment should be performed only by qualiﬁed service personnel. The brewer should be unplugged when servicing, except when electrical tests are required and the test procedure speciﬁcally states to plug in the brewer.

COMPONENT ACCESS

WARNING - Unplug the brewer before the removal of

any panel or the replacement of any component.

All components are accessible by the removal of the top cover, front access panel, warmer base plate and/or server platform cover. The covers and panels are attached with slotted head screws as follows:

SINGLE & SINGLE SH top cover (1) #4-40

Contents

Brewer Selector Switch ........................................ 12

Bypass Valve ........................................................ 11

Circuit Breakers .................................................... 14

Contactor Assembly ............................................. 15

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

Dispense Valve ..................................................... 18

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

Level Control Board and Level Probe ...................21

Limit Thermostat ..................................................23

Main Power Switch ..............................................45

ON/OFF Switch (Warmer) ..................................... 24

Overﬂow Protection Switch .................................. 25

Receptacle ...........................................................26

Rectiﬁers .............................................................. 26

Relay .................................................................... 27

Solenoid ............................................................... 33

Start Switches (Brew) ..........................................35

Tank Heaters ........................................................36

Timers (Early Models) .......................................... 37

Digital Timer (Late Models) .................................. 40

Transformers........................................................42

Warmer Elements.................................................44

Wiring Diagrams .................................................. 46

DUAL & DUAL SH top cover (4) #4-40

SINGLE front access panel (4) #6-32

SINGLE SH front access panel (8) #6-32

DUAL front access panel (5) #6-32

DUAL SH front access panel (11) #6-32

SINGLE & DUAL warmer base (4) #6-32

SINGLE SH & DUAL SH server platform (4) #6-32

Page 10

41976 031709

SERVICE (cont.)

CAUTI

HOT WATE

INUTES

BUNN-O-MATIC

P/N 2620- 120 VAC

MINUTES

BUNN-O-MATIC

P/N 2620- 120 VAC

1 gal

AUTI

ON:

MERS

URFA

BYPASS VALVE

P773

FIG. 1 BYPASS VALVES

Location: The bypass valves are located on the sprayhead panel inside the hood.

Test Procedures:

1. Disconnect the brewer from the power source and

place a server beneath the funnel.

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.

4. Check the bypass valve for coil action. Place the ON/

OFF switch in the "ON" position, press and release

the BREW switch. Listen carefully in the vicinity of

the bypass valve for a "clicking" sound as the coil

magnet attracts and repels the plunger.

5. Disconnect the brewer from the power source.

If the sound is heard as described, there may be a blockage in the bypass valve or the water line to the sprayhead. Remove the bypass valve and inspect for wear, and remove waterborne particles. If the sound is not heard as described, proceed to #6.

6. Connect the voltmeter lead ends to the bypass valve coil terminals. Connect the brewer to the power source. With the selector switch in the 1 or 1-1/2 gallon position, place "ON/OFF" Switch in the "ON" position. Press and release the brew switch. The indication must be:

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

three wire 120/208 volt and three wire 120/240 volt models.

b.) 200 to 240 volts ac for two wire 200 or 240

volt models.

7. Disconnect the brewer from the power source.

If voltage is present as described, but no coil action is observed, nor "clicking" heard, bypass valve is defective. Replace valve and test again to verify repair. If voltage is not present as described, refer to Wiring Diagrams and check the brewer wiring harness. Also check the control board for proper operation.

Removal and Replacement:

1. Remove the wires from the bypass valve.

2. Drain enough water from the tank so bypass valve is above the water line.

3. Remove water lines from bypass valve.

4. Remove the two nuts retaining the bypass valve inside the hood and remove bypass valve.

5. Remove hose barb ﬁtting and attach to new bypass valve.

6. Install new bypass valve with hose barb ﬁtting.

7. Reconnect the water tubes and the wires to the bypass valve.

8. Refer to Fig. 2 when reconnecting the wires.

NOTE: If one of the terminals is marked "I", connect WHI/GRN wire to it.

WHI/GRN to Dispense Valve

WHI/VIO to Brew Selector Switch

P774

FIG. 2 BYPASS VALVE TERMINALS

Page 11

41976 031709

SERVICE (cont.)

START

ON / WAR

MER

SELECTOR

READY

EADY

ON / WAR

MER

START

1⁄2

l1 g

1⁄2

gal

SELECTOR

1⁄2

gal

BREW SELECTOR SWITCH

FIG. 3 BREW SELECTOR SWITCHES

P775

12. Reconnect the pink wire to the grind switch.

13. Disconnect the tan wire from the left or right selector switch and tan wire from interface socket.

14. Check for continuity across the tan wires.

15. Reconnect the tan wires.

16. With the selector switch set at the medium and large batch positions, disconnect the white/violet from the bypass valve.

17. Check for continuity across the white/violet wire and terminal on bypass valve.

18. Reconnect the white/violet wire to the terminal on the bypass valve.

19. Disconnect the white/red wire from the dispense valve.

20. Check for continuity across white/red wire and terminal on dispense valve.

21. Reconnect white/red wire to the terminal on the dispense valve.

Location: The brew selector switch(es) are mounted in the front panel of the hood.

Test Procedure (Early model Selector Switch):

1. Disconnect the brewer from the power supply.

2. Separate the connector on the selector switch harness from the brew timer circuit board.

3. Carefully slide the plastic cover off of the connector from the switch harness.

4. Check for continuity across the pink and tan wires on the connector when the switch is in the small batch position. Continuity must not be present in any other switch position.

5. Check for continuity across the pink wire and gray wire when the switch is in the medium batch position. Continuity must not be present in any other position.

6. Reattach the connector to the brew timer circuit board.

7. Disconnect the gray wire from the left or right selector switch and gray wire from the interface socket.

8. Check for continuity across the gray wires.

9. Reconnect the gray wires from the selector switches and the interface socket.

10. Disconnect the pink wire from the left or right selector switch to the grinder switch.

11. Check for continuity across the pink wire and the terminal on the grind switch.

Page 12

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

Removal and Replacement:

1. Disconnect the connector on the selector switch harness from the brewer timer circuit board.

2. Disconnect wires from the selector switch, interface socket, dispense valve and bypass valve.

3. Loosen the set screw on the switch knob.

4. Remove the 9/16" nut and washer holding the switch to the hood.

5. Remove the switch.

6. Install the new switch. The positioning tab must be in the hole in the hood for proper switch and knob alignment.

7. Install the knob so that the arrow lines up in the large batch position when the switch is turned to the full right position.

8. Reattach the connector to the brew timer circuit

board.

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

41976 031709

SERVICE (cont.)

BREW SELECTOR SWITCH (cont.)

WHI/VIO to By-Pass Valve

WHI/RED to Dispense Valve

GRY to Interface Socket

PNKtoInterfaceSocket

TAN to Interface Socket

To Timer

EARLY MODEL SELECTOR SWITCH

YEL to Timer

PNKtoGrinderInterface

BLU to Timer

ORN to Timer

GRY to Grinder Interface

TAN to Grinder Interface

PNK

TAN

GRY

5. Check for continuity across terminals (e) and (5).

When the selector switch is in the small batch position, continuity should not be present. When the selector switch is in the medium or large batch positions, continuity should be present.

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

Removal and Replacement:

1. Disconnect all wires from the brew selector

switch.

2. Loosen the set screw on the switch knob.

3. Remove the 9/16" nut and washer holding the

switch to the hood.

4. Remove the switch.

5. Install the new switch. The positioning tab must

be in the hole in the hood for proper switch and knob alignment.

6. Install the knob so that the arrow lines up in the

large batch position when the switch is turned to the full right position.

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

WHI/VIO to By-Pass Valve

LATE MODEL SELECTOR SWITCH

WHI/RED to Dispense Valve

P1388

FIG. 4 BREW SELECTOR SWITCH TERMINALS

Test Procedure (Late model Selector Switch):

1. Disconnect the brewer from the power supply.

2. Disconnect all wires from the brew selector switch.

3. Check for continuity across terminals (b) and (1) when the switch is in the small batch position. Continuity must not be present in any other switch position.

4. Check for continuity across terminals (b) and (2) when the switch is in the medium batch position. Continuity must not be present in any other position.

Page 13

41976 031709

SERVICE (cont.)

CIRCUIT BREAKERS

Removal and Replacement:

1. Remove the wires from the circuit breaker.

2. Compress the clips on the back side of the server platform and gently push the circuit breaker through the opening in the server platform.

3. Push the new circuit breaker into the opening in the server platform until the clips snap into position.

4. Reconnect the wires to the circuit breaker.

TER

HOT WA

ON TI U

TIO

ARD DECANTER

CAU

DISC :

PTY M

ATCHED

RIC

ED D

SCR

WHEN E

IGH

OIL

ELEC

TED . EA

D ON .

PO SE

X U .

E R

ENTS O .

TIO

NJURY

ELEM

ORA

NTS

NTE

MATIC

MPLY RISKS I

5 BUNN-O 8 19

O CO

FUNNEL CO

ARE HOT

E T

AILUR F

658

PN:

5. Refer to Fig. 6 when reconnecting the wires.

BLU/BLKtoTransformer#12

FIG.5CIRCUITBREAKERS

P1361

(SH Brewers only)

Location The circuit breakers are located on the lower front of the brewer, mounted on the server platform just above the spring contact receptacle assembly.

Test Procedures:

1. Disconnect the dispenser from the power source.

2. Remove the wires from the circuit breaker.

3. Check for continuity between the terminals. Continuity must be present between the terminals.

If continuity is present as described the circuit breaker is functioning properly. If continuity is not present as described, press reset button and repeat step #3, if continuity is not present as described, replace the circuit breaker.

BLU/BLKtoRectier"AC"

P1330

FIG.6CIRCUITBREAKERTERMINALS

Page 14

41976 031709

SERVICE (cont.)

CONTACTOR ASSEMBLY

MINUTE

BUNN-O-MATIC

20- 120 VAC

P/N 26

wire 120/208 volt models and three wire 120/240 volt models.

b.) 200 to 240 volts ac for two wire 200 or 240

volt models.

5. Disconnect the brewer from the power source.

If voltage is present as described, proceed to #6.

gal1 ga

1⁄2

gal

1⁄2

READY

SELECTOR

/ WARMER

P/N 2620- 120 VAC

ON / WA

SELECTOR

Y EAD R

l1 gal a g

2 1⁄

l ga

2 1⁄

MINUTES

BUNN-O-MATIC

START

RMER

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

6. Check for continuity between the two black wires of the contactor coil.

If continuity is present as described, reconnect one black wire to red or white wire from the terminal block and the other black wire to the black wire from the

S ARE

RFACE

AND SU

ARMER

ON:

HOT

I T

ON I

CAU

control thermostat. Reinstall capillary tube into the tank to a line 7" above the bulb and proceed to #7. If continuity is not present as described, replace the contactor.

P796

FIG. 7 CONTACTOR ASSEMBLY

Location: The contactor assembly is located inside the hood just to the rear of the dispense valve (Right side for DUAL and DUAL SH models).

Test Procedures: Mechanical Thermostat (Brewers with or without Recovery Booster)

1. Disconnect the brewer from the power source.

2. Disconnect the white wire of the two pole 120V terminal block, white wire of the three pole 120/208V or 120/240V or the red wire of the two pole 200V or 240V terminal block and the black wire of the contactor coil. Disconnect the black wire of the control thermostat from the remaining black wire of the contactor coil.

3. Gently remove the capillary bulb and grommet from the tank.

4. With a voltmeter, check the voltage across the white wire from the terminal block on 120, 120/208, 120/240 volt units or the red wire from 200 or 240 volt units and the black wire from the control thermostat when the thermostat is turned clockwise to the "FULL ON" position. Connect the brewer to the power source. The indication must be:

a.) 120 volts ac for two wire 120 volt models, three

Page 15

7. Locate the white wire or red wire on L1 terminal and black wire on the L2 terminal on the contactor.

8. With a voltmeter, carefully check the voltage across the white or red and black wires. The indication must be:

a.) 120 volts ac for two wire 120 volt models, 208

volts ac for three wire 120/208 volt models and 240 volts ac for three wire 120/240 volt models.

b.) 200 to 240 volts ac for two wire 200 or 240

volt models.

9. Disconnect the brewer from the power source.

If voltage is present as described, proceed to #10. If voltage is not present as described, refer to the Wiring Diagrams and check brewer wiring harness.

10. Check for continuity across the terminals on the left side of the contactor by manually closing the contacts. Continuity must not be present when the contact is released.

11. Check for continuity across the terminals on the right side of the contactor by manually closing the contacts. Continuity must not be present when the contact is released.

If continuity is present as described, the contactor is operating properly.

41976 031709

SERVICE (cont.)

CONTACTOR ASSEMBLY (cont.)

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

Test Procedures : Electronic Control (Brewers w/Recovery Booster)

1. Disconnect the brewer from the power source.

2. Disconnect the gray wire from the black wire on the rear of the contactor coil and white /brown wire from the black wire on the front of the contactor coil.

3. With a voltmeter, check the voltage across the gray wire and white/brown wire with both "ON/ OFF" switches in the "ON" position. Connect the brewer to the power source and press both start switches. The indication must be:

a.) 120 volts ac for three wire 120/208 volt models

and three wire 120/240 volt models.

b.) 200 to 240 volts ac for two wire 200 or 240

volt models.

4. Disconnect the brewer from the power source.

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

5. Disconnect the blue and red wires from the contactor terminals. Check for continuity across the terminals of the contactor by manually closing the contacts. Continuity must not be present when the contact is released.

3. Securely install the new contactor inside the hood.

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

WHI L1 to Terminal Block (White Insert)

RED L1 to Terminal Block (Red Insert)

BLKL2toLimitThermostat

BLKto WHI Lead from the Two

Pole 120V Terminal Block

BLKtoWHILeadfromtheThree

Pole 120/208V or 120/240V Terminal Block

BLKtoREDLeadfrom the Two

Pole 200V or 240V Terminal Block

BLK T2 to TankHeater

RED T1 to Tank Heater

BLKto BLK Lead from

Thermostat

P828

SINGLE and SINGLE SH models

DUAL and DUAL SH models

RED L1 to Terminal Block (Red Insert)

BLKL2toTerminalBlock

(Black Insert)

BLKtoWHILeadfromthe

Three Pole 120/208V or 120/240V Terminal Block

BLKtoREDLeadfromthe

Two Pole 200V or 240V Terminal Block

MECHANICAL THERMOSTAT W/RECOVERY BOOSTER

BLKT2toLeftTankHeater BLKT2toRightTankHeater

RED T1 to Left Tank Heater RED T1 to Right Tank Heater

BLKtoBLKLeadfromThermostat

If continuity is present as described, reconnect the blue and red wires to the contactor terminals. Connect one black lead from the contactor coil to the gray wire and the white/brown wire to the remaining black lead of the contactor coil. The contactor is operating properly. If continuity is not present as described, replace the contactor.

Removal and Replacement:

1. Remove all wires from the contactor.

2. Remove the two #10-32 slotted head screw securing contactor to the inside of the hood.

Page 16

RED T1 to Terminal Block (Red Insert)

BLU L1 to Left Tank Heater

BLKtoGRYonRelay

ELECTRONIC CONTROL W/RECOVERY BOOSTER

BLKtoWHI/BRNtoLeft

Dispense Valve

FIG. 8 CONTACTOR TERMINALS

P778

41976 031709

SERVICE (cont.)

CONTROL THERMOSTAT

Location: The control thermostat is located inside the lower left front of the brewer on the component bracket.

1. Disconnect the brewer from the power source.

2. Locate the blue wire on the control thermostat.

3. With a voltmeter, check the voltage across the

blue wire on the control thermostat and the white insert on the two or three pole 120V, 120/208V, 120/240V terminal block and the red insert on two pole 200V, 240V terminal block. Connect the brewer to the power source. The indication must be:

a.) 120 volts ac for two wire 120V models, three

wire 120/208 volt models and three wire 120/240 volt models.

b.) 200 to 240 volts ac for two wire 200 or 240

volt models.

4. Disconnect the brewer from the power source.

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

5. Locate the black wires from the control thermostat.

6. Gently remove the capillary bulb and grommet from the tank.

7. With a voltmeter, check the voltage across the black wires of the control thermostat and the white insert on the two pole or three pole 120V, 120/208V, 120/240V terminal blocks and the red insert on two pole 200V, 240V terminal blocks when the control thermostat is turned "ON" (fully clockwise). Connect the brewer to the power source. The indication must be:

a.) 120 volts ac for two wire 120V models, three

wire 120/208 volt models and three wire 120/240 volt models.

b.) 200 to 240 volts ac for two wire 200 or 240

volt models.

Voltage must not be indicated across these ter-

minals when the thermostat is turned "OFF" (fully counterclockwise).

8. Disconnect the brewer from the power source.

If voltage is present as described, reinstall the capillary tube into the tank to the line 7" above the bulb, the control thermostat is operating properly. If voltage is not present as described, replace the thermostat.

1 ga l a g

2 1⁄

ELECTOR S

WARMER

UTES

C N I

M N-O-MATIC

BUN

P/N 2620- 120 V

/ N O

TOR

LEC E S

EADY

l a

2 ⁄

1 ga l ga

1⁄2

UTES N I

MATIC

N-O-

BUN

20- 120 V

N 26

START ON /

T R A

RMER

ARE

CES A F

D SUR

ARME

N: IO T

ON HOT WATE I

CAU

CAUT

FIG. 9 CONTROL THERMOSTAT

al g

1⁄

READY

Removal and Replacement:

1. Remove wires from the control thermostat.

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

3. Remove the #8-32 slotted head screw holding the control thermostat to the component bracket.

4. Slide the grommet to the line 7" above the bulb on the new capillary tube.

5. Insert the capillary bulb through the hole in the tank lid and press the grommet ﬁrmly and evenly so that the groove in the grommet ﬁts into the tank lid.

P779

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

41976 031709

Page 17

SERVICE (cont.)

CONTROL THERMOSTAT (cont.)

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

cal termination and not kinked.

7. Using a #8-32 slotted head screw fasten the control thermostat to the component bracket.

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

9. Adjust the control thermostat as required.

DISPENSE VALVE

gal1 ga

1⁄2

gal

1⁄2

READY

SELECTOR

ON / WARMER

P/N 2620- 120 VAC

MINUTE

BUNN-O-MATIC

20- 120 VAC

P/N 26

RMER

ON / WA

SELECTOR

READ

al1 gal

2 ⁄

2 1⁄

MINUTES

BUNN-O-MATIC

STA

START

BLU to Ready Light(s) BLU to Overﬂow Protection Switch

BLKtoBLKLeadofContactorCoil BLKtoReadyLight(s)

FIG. 10 CONTROL THERMOSTAT

TERMINALS

P780

FIG. 11 DISPENSE VALVE

P796

Location: Dispense valves are located inside the hood in the center of each sprayhead panel.

Test Procedures:

1. Disconnect the brewer from the power source.

2. Disconnect the wires from the right dispense valve and check the voltage across the white/violet wire and white/green wire. Connect brewer to the power source. Place the "ON/OFF" switch in the "ON" position, press and release the start switch. The indication must be:

a.) 120 volts ac for two wire 120V models, three

wire 120/208 volt models and three wire 120/240 volt models.

b.) 200 to 240 volts ac for two wire 200 or 240

volt models.

3. Disconnect brewer from the power source.

4. Disconnect the wires from the left dispense valve and check voltage across the white/red wire and the white/brown wire. Connect the brewer to the power source. Place the "ON/OFF" switch in the "ON" position and press and release the start switch. The indication must be:

a.) 120 volts ac for two wire 120V models, three

wire 120/208 volt models and three wire 120/240 volt models.

b.) 200 to 240 volts ac for two wire 200 or 240

volt models.

5. Disconnect brewer from power source.

Page 18

41976 031709

SERVICE (cont.)

DISPENSE VALVE (cont.)

If voltage is present as described in steps 2 & 4 proceed to #6. If voltage is not present as described, refer to the Wiring Diagrams and check brewer wiring harness.

6. Check for continuity across the dispense valve coil terminals.

If continuity is present as described, reconnect the wires to the dispense valve and proceed to #7 If continuity is not present as described, replace the dispense valve.

7. Check the dispense valve for coil action. Connect the brewer to power source. Place the ON/OFF" switch in the "ON" position, press and release the start switch. Listen carefully in the vicinity of the dispense valve for a "clicking" sound as the coil magnet attracts and repels the plunger.

8. Disconnect the brewer from the power source.

WHI/VIO to Right Timer TL1 WHI/VIO to Right ON/OFF Switch WHI/RED to Right Brew Selector Switch

WHI/GRN to Right Timer TL4 WHI/GRN to Right By-Pass Valve

SINGLE Brewers & RIGHT on DUAL Brewers

WHI/RED to Left Timer TL1 WHI/RED to Left Brew Selector Switch WHI/RED to Left ON/OFF Switch

WHI/BRN to Left Timer TL4 WHI/GRN to Left By-Pass Valve

LEFT on DUAL Brewers

FIG. 12 DISPENSE VALVE TERMINALS

P782

If the sound is heard as described, there may be a blockage in the dispense valve or the water line to the dispense valve. Remove the dispense valve and inspect for wear, and remove waterborne particles. If the sound is not heard as described, replace the dispense valve.

Removal and Replacement:

1. Disconnect wires and water tubes from dispense valve.

2. Drain enough water from the tank so the dispense valves are above the water line.

3. Remove dispense valve from the sprayhead panel.

4. Install new dispense valve.

5. Reconnect the water lines and the wires to the dispense valve.

6. Refer to Fig. 12 when reconnecting wires.

Page 19

41976 031709

SERVICE (cont.)

GRINDER SELECTOR SWITCH

gal

2 ⁄ 1

1 gal

gal

⁄2 1

DY A

SELECTO

RMER

RT ON / WA

1⁄

1 gal al g

2 ⁄ 1

START

N / WARMER

SELECTO

READY

FIG. 13 GRINDER SELECTOR SWITCH

(DUAL and DUAL SH BREWERS only)

Location: The grinder selector switch is located in the upper center on the front of the hood.

STA

P786

PNKtoPNKLeadfrom

Right Brew Selector Switch

PNKtoPNKLeadfromInterface

Socket

PNKtoPNKLeadfrom

Left Brew Selector Switch

P787

FIG. 14 GRINDER SELECTION

SWITCH TERMINALS

Test Procedure:

1. Disconnect the brewer from the power source.

2. Remove all wires from the switch terminals.

3. Place the selector switch in the left position. 4 Check for continuity across the center and right

terminals on the rear of the switch.

5. Continuity must not be present across the center and left terminals on the rear of the switch.

6. Check the bottom row, then the top row of terminals.

If continuity is present as described proceed to #7. If continuity is not present as described replace the switch.

7. Place the selector switch in the right position.

8. Check for continuity across the center and left terminals on the rear of the switch.

9. Continuity must not be present across the center and right terminals on the rear of the switch.

10. Check the bottom row, then the top row.

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

11. Refer to Fig. 14 when reconnecting the wires.

Page 20

41976 031709

+ 45 hidden pages