Bunn FMD-3 User Manual

FMD-3

(S/N FMD0013000-UP)

OPERATING & SERVICE MANUAL

BUNN-O-MATIC CORPORATION

POST OFFICE BOX 3227

SPRINGFIELD, ILLINOIS 62708-3227

PHONE: [phone] FAX: [phone]

29170.0000E 01/06 © 1998 Bunn-O-Matic Corporation

INTRODUCTION

This equipment dispenses hot beverages or soup on demand from powdered product. It has three hoppers.
This equipment may also dispense cold beverages from powdered product from the left dispense station. It is
for indoor use only on a sturdy counter or shelf.

WARRANTY

Bunn-O-Matic Corp. (“Bunn”) warrants the equipment manufactured by it to be commercially free from defects
in material and workmanship existing at the time of manufacture and appearing within one year from the date of
installation. In addition:

1.) Bunn warrants electronic circuit and/or control boards to be commercially free from defects in material and

workmanship for two years from the date of installation.

2.) Bunn warrants the compressor on refrigeration equipment to be commercially free from defects in material

and workmanship for two years from the date of installation.

3.) Bunn warrants that the grinding burrs on coffee grinding equipment will grind coffee to meet original factory

screen sieve analysis for three years from date of installation or for 30,000 pounds of coffee, whichever comes first.

This warranty does not apply to any equipment, component or part that was not manufactured by Bunn or that,
in Bunn’s judgement, has been affected by misuse, neglect, alteration, improper installation or operation, improper
maintenance or repair, damage or casualty.

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.

The Buyer shall give 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. If requested by Bunn, the Buyer
shall ship the defective equipment prepaid to an authorized Bunn service location. If Bunn determines, in its sole
discretion, that the equipment does not conform to the warranty, Bunn shall repair the equipment with no charge
for parts during the warranty period and no charge for labor by a Bunn Authorized Service Representative during
the warranty period. If Bunn determines that repair is not feasible, Bunn shall, at its sole option, 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, AS
SPECIFIED HEREIN, TO REPAIR OR, AT BUNN’S SOLE OPTION, 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.

2

29170 032900

USER NOTICES

Carefully read and follow all notices on the equipment and in this manual. They were written for your protection.

All notices are to be kept in good condition. Replace any unreadable or damaged labels.

28301.0003

00831.0000

28328.0000

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). For models installed
outside the U.S.A., comply with the applicable
Plumbing /SanitationCode.

00656.0000

MECHANICAL THERMOSTAT

28368.0000

160°

-

+

TEMPERATURE

ADJUSTMENT

120VAC

190°

HEATER

26527.0002

THERMOSTAT ASSEMBLY

BUNN-O-MATIC CORP

®

ELECTRONIC THERMOSTAT

26536.0002

3

29170 011906

INITIAL SET-UP

1. Locate the drip tray assembly above the dispenser nested in the packing material.

2. Remove the drip tray and the drip tray cover and set them aside.

3. Remove the water strainer assembly from the drip tray and set it aside.

4. Remove the four legs from the packaging material, apply non-skid pads to the bottom of the legs and securely

install the legs in the dispenser base.

ELECTRICAL REQUIREMENTS

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

The 120 volt version of this dispenser has an attached cordset. The mating connector must be a NEMA 5-15R.
The 120/208 volt and the 120/240 version of this dispenser has an attached cordset. The mating connector must
be a NEMA 14-20R.
The 240 volt version of this dispenser has an attached cordset without plug.

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. Open the front door of the dispenser and place the heater switch in the “OFF” (upper position).

4. Connect the dispenser to the power source.

5. If plumbing is to be hooked up later be sure the dispenser is disconnected from the power source. If

plumbing has been hooked up, the dispenser is ready for

Initial Fill & Heat.

PLUMBING REQUIREMENTS

This dispenser must be connected to a COLD WATER system with operating pressure between 20 and 90 psi (138
and 620 kPa) from a 1⁄2" or larger supply line. A shut-off valve should be installed in the line before the dispenser.
Install a regulator in the line when pressure is greater than 90 psi (620 kPa) to reduce it to 50 psi (345kPa). The
water inlet fitting is 1⁄4" flare.
NOTE - Bunn-O-Matic recommends 1⁄4" copper tubing for installations of less than 25 feet and 3⁄8" for more than
25 feet from the 1⁄2" water supply line. At least 18 inches of an FDA approved flexible beverage tubing, such as
reinforced braided polyethylene or silicone, before the dispenser will facilitate movement to clean the countertop.
Bunn-O-Matic does not recommend the use of a saddle valve to install the dispenser. 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). For models installed outside the
U.S.A., you must comply to the applicable Plumbing/Sanitation Code for your area.

PLUMBING HOOK-UP

1. Securely attach the short piece of tubing on the water strainer assembly to the inlet fitting on the bottom of

the dispenser.

2. Flush the water line and securely attach it to the flare fitting on the water strainer assembly.

3. Turn on the water supply.

4

29170 011906

INITIAL FILL & HEAT

CAUTION - The dispenser must be disconnected from the power source throughout the initial fill & heat, except

when specified in the instructions.

1. Turn on the water supply and connect the dispenser to the power source.

2. Water will automatically flow into the tank to the proper level and then shut off. This will take less than five
minutes.

3. When the tank is full of water, open the front door and place the heater switch in the “ON” (lower) position.
A tank full of cold water will take approximately forty minutes for the water to heat on 120 volt versions, and
twenty minutes on 120/240 and 240 volt versions.

During this waiting period, complete these dispenser set-up steps:

a. Place a set of keyholes in the splash panel over the screws beneath the hopper access door and push down
gently.
b.Place the drip tray onto the supports on the splash panel. Hook the tabs on the rear of the drip tray through
the holes in the splash panel. Set the drip tray cover in place.
c. Fill the hopper(s) with the dry product to be dispensed.

LIQUID LEVEL CONTROL

The system automatically maintains the hot water tank’s level by energizing the refill solenoid when the water level
drops below the liquid level probe. If the system has not successfully refilled in 7 1/2 minutes, a refill error occurs.

When a refill error occurs, the refill solenoid is de-energized and the rinse L.E.D. will flash about once every 5
seconds.

Once the cause of the refill error has been investigated (see the troubleshooting guide) and cured, the system can
be reset by disconnecting (for at least 5 seconds) and then reconnecting the power to the machine.

RINSE TIMER

The dispenser is shipped from the factory with the rinse timer disabled. To enable the rinse timer, remove
power from the dispenser, remove the lower access panel, and remove the jumper from J1 of the control
board. Replace the lower access panel, and return power to the dispenser.

When enabled, the rinse timer automatically keeps track of the time since the dispenser was last run through a
rinse sequence. If the dispenser detects that a rinse sequence has not been run for 8 hours, the rinse L.E.D. will
flash continually. If, after an additional 4 hours (12 hours total), a rinse sequence has still not been run, the rinse
L.E.D. will light continuously, and the hopper drives will be disabled until a rinse sequence has been run.

RUNNING A RINSE SEQUENCE

1. Place the rinse/run switch in the rinse position.

2. Sequentially, or simultaneously, at each of the three positions dispense for at least 10 seconds.

3. After the rinse L.E.D. has extinguished, the rinse timer is reset.

4. Return the rinse/run switch to the run position.

DISPENSER USE

1. Simply place a cup on the drip tray beneath the desired dispensing tip.

2. Press the button to froth and dispense the beverage.

3. Release the button when the cup is approximately 2/3 full and allow the mixing chamber to drain.

NOTE - The mixing chamber must drain at the end of each dispense.

5

29170 091598

COLD BEVERAGE SET-UP (OPTIONAL)

Cold beverages may be dispensed from the left dispense position. Simply place the HOT/COLD switch near the
left whipper chamber in the “COLD” (upper) position.

CLEANING

Refer to the decal inside the hopper access door for cleaning recommendations and procedures.
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.

ADJUSTMENTS

The hot or cold beverage solenoids are preset to dispense approximately 9/
be adjusted:

1. Disconnect the dispenser from the power source.

2. Remove the small left side access panel.

3. Rotate the control at the base of the desired solenoid(s) clockwise to decrease or counterclockwise to increase
the amount of water.

4. For cold beverage adjustment remove the 1-1/2” plug on the lower left side of the dispenser and rotate the
needle valve clockwise to decrease or counterclockwise to increase the amount of cold water.

ounce per second. This amount can

10

HOPPER DISPENSE RATE OF PRODUCT

NOTE: The hopper dispense rates are preset at the factory. With 22 tooth gear and auger wire the preset dispense

rate is approximately 3 to 5 grams per second. With 30 tooth gear and auger wire the preset dispense is approxi­mately 5 to 7 grams per second. The hopper dispense rates can be individually programmed to a range of
dispense rates from approximately 1.5 to 12 grams per second, as follows:

1. Place the rinse/run switch in the center (program) position.

2. Hold the increase/decrease switch in the desired (increase or decrease) position.

3. While holding the increase/decrease switch, press and release the dispense switch for the chamber you wish
to adjust. Each time the dispense switch is pressed, the rinse L.E.D. will flash, and the motor speed for that
hopper will be increased/decreased by approximately 2 1/2%.

4. Return the rinse/run switch to the run position after hopper motor speed adjustments are complete.

5. Once any of the three hopper motors has been programmed to the desired speed, either or both of the other
hopper motors can be set to the same speed as follows:
a. Place the rinse/run switch in the center (program) position.
b. Press and hold the dispense switch that has been programmed for the correct speed.

NOTE: Care must be taken not to exceed 5 seconds, or a hopper throw test will occur.

c. Momentarily press the dispense switch for the hopper motor to be programmed. The rinse L.E.D. will light
for approximately 1 second, indicating that the speeds have been set equal.
d. Release both dispense switches.
e. Repeat step 5. b. through 5. d. for remaining hopper motor if desired.
f. Return the rinse/run switch to the run position after hopper motor speed adjustments are complete.

HOPPER THROW TEST

The hopper throw rate, grams per second (g/s) or ounces per second (oz./s), can be checked by automatically
running the hopper motor for 10 seconds.

1. Remove the steam collector and mixing chamber from under the hopper to be checked.

2. Position a small cup under the hopper outlet.

3. Place the rinse/run switch in the center (program) position.

6

29170 011906

HOPPER THROW TEST(cont.)

4. Press and hold the dispense switch of the appropriate chamber for 5 seconds. The hopper motor will run for

10 seconds at the programmed speed.

5. Remove the cup and weigh the dispensed product. To calculate the throw rate (g/s or oz./s), divide the total

weight of the dispensed product by 10.

6. Replace the mixing chamber and steam collector, and return the rinse/run switch to the run position.

DRAINING THE HOT WATER TANK

CAUTION - The dispenser must be disconnected from the power source throughout these steps.

1. Disconnect the dispenser from the power source.

2. Open front door and place tank heater switch in the “OFF” (upper) position.

3. Shut off and disconnect the incoming water supply.

4. Remove the top panel.

5. Gently remove one of the grommets from the tank lid.

6. Insert a tube to the bottom of the tank and syphon ALL of the water out.

NOTE - The dispenser must be refilled using the INITIAL FILL & HEAT steps before reconnecting to the power
source.

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 or 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 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 unit is heated at all times. Keep away from combustibles.

WARNING – • Exercise extreme caution when servicing electrical equipment.

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

• Follow recommended service procedures

• Replace all protective shields or safety notices

7

29170 091598

TROUBLESHOOTING (cont.)

PROBLEM

PROBABLE CAUSE

REMEDY

Product will not dispense

1. No water

2. No power or incorrect voltage to
the dispenser

3. Dispense Switch

Water lines and valves to the dis­penser must be open.

(A1) Check for 120 volts across
the black and white wires on two
wire 120 volt dispenser.
(A2) Check for 120 volts across
the red and white wires and the
black and white wires and 240
volts across the red and black wires
on three wire 120/240 volt dis­penser.
(A3) Check for 240 volts across
the white and black wires on two
wire 240 volt dispenser.

(B) Check circuit breakers or fuses.

Refer to

Service

- Dispense Switch

for testing procedure. See page 22

4. Dispense Solenoid Valve
(Hot or Cold)

5. Solenoid Valve (Inlet)

6. Control Board

7. Overflow Protection Switch

8. Auger Drive

Refer to

Service

- Dispense Sole­noid Valve for testing procedures.
See page 33 or 34

Refer to

Service

- Solenoid Valve
(Inlet) for testing procedures. See
page 35

Refer to

Service

- Control Board
and Probe for testing procedures.
See page 18

Refer to

Service

- Overflow Protec­tion Switch for testing procedures.
See page 31

Refer to

Service

- Auger Drive. See

page 13

8

29170 080900

TROUBLESHOOTING (cont.)
PROBLEM

PROBABLE CAUSE

REMEDY

Product will not dispense (cont.)

Water is not hot

9. Water Strainer

10. 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.

11. Rinse cycle not run for 12 hours.

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

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

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

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

Refer to

Operations

- Rinse Timer.

See page 5

Refer to

Service

- Limit Thermostat

for testing procedures. See page 30

Spitting or excessive steaming

2. Control Thermostat

3. Tank Heater

4. Tank Heater Switch

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

2. Control Thermostat

Refer to

Service

- Control Thermo­stat for testing procedures. See page
20

Refer to

Service

- Tank Heater for

testing procedures. See page 36

Refer to

Service

- Tank Heater Switch

for testing procedures. See page 38

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

Refer to

Service

- Control Thermo­stat for testing procedures. See page
20

9

29170 080900

TROUBLESHOOTING (cont.)
PROBLEM

PROBABLE CAUSE

REMEDY

Dripping from dispense tip

Water flows into tank continuously

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

2. Dispense Solenoid Valve
(Hot or Cold)

1. Control Board

2. Solenoid Valve (Inlet)

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

Remove the dispense solenoid valve
and clear any obstructions. Rebuild
or replace the valve if necessary. See
page 33 or 34

Refer to

Service -

Control Board and
Probe for testing procedures. See
page 18

Refer to

Service

- Solenoid Valve
(Inlet) for testing procedures. See
page 35

Product overflows container

3. Overflow Protection Switch

1. Dispense Switch

2. Dispense Solenoid Valve
(Hot or Cold)

Refer to

Service

- Overflow Protec­tion Switch for testing procedures.
See page 31

Refer to

Service -

Dispense Switch

for testing procedures. See page 22

Remove the solenoid valve and clear
any obstructions. Rebuild or replace
the valve if necessary. See page 33
or 34

10

29170 080900

TROUBLESHOOTING (cont.)
PROBLEM

PROBABLE CAUSE

REMEDY

Weak product

1. Water temperature

2. Whipper Motor

3. Frother

Place an empty container beneath
the dispense tip. Initiate a dispense
cycle and check the water tempera­ture immediately below the dispense
tip with a thermometer.
(A) Reading for mechanical thermo­stat models should be 180°F(82°C)
to 200°F (93°C) (see thermostat tem­perature settings decal in

TICES

on page 3.

USER NO-

(B) Reading for electronic thermo­stat should be185°F(85°C) to190°F
(88°C).
Adjust the control thermostat to in­crease or decrease the water tem­perature. Replace if necessary.

Refer to

Service

- Whipper Motor for

testing procedure. See page 25

Refer to

Service

- Frother Compo-

nents. See page 24

4. Dispense Solenoid Valve
(Hot or Cold)

5. Auger Drive

6. Auger Spring

7. Auger Motor

8. Rinse/Run Switch

9. Rinse Timer

Refer to

Service

- Dispense Solenoid
Valve for test procedures. See page
33 or 34

Refer to

Service

- Auger Drive Com-

ponents. See page 13

Refer to

Service

- Auger Drive Com-

ponents. See page 13

Refer to

Service

- Auger Drive Com-

ponents. See page 16

Refer to

Service -

Rinse/Run Switch

for test procedures. See page 32

Refer to

Operations

- Rinse Timer.

See page 5

11

29170 080900

TROUBLESHOOTING (CONT.)

PROBLEM

Dispenser is making unusual
noises

Excess dust

PROBABLE CAUSE

1. Plumbing Lines

2. Water Supply

3. Tank Heater

1. Fan

2.Control Board

REMEDY

Plumbing lines should not be rest­ing on the counter top.

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

(B) Water pressure to the dispenser
must not exceed 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 the tank
heater. See page 36

Refer to

Service

- Fan for testing

procedures. See page 24

Refer to

Service

- Control Board for

testing procedures. See page 18

Display not lit

1. Lamp

2. Lamp Holder

3. Starter - Lamp

4. Ballast

Refer to

Service

- Lamp, see page 28

for lamp replacement.

Refer to

Service

- Lamp Holder for

testing procedures. See page 28

Refer to

Service

- Starter for testing

procedures. See page 29

Refer to

Service

- Ballast for testing

procedures. See page 17

12

29170 080900

SERVICE

This section provides procedures for testing and
replacing various major components used in this
dispenser should service become necessary. Refer to

Troubleshooting

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

COMPONENT ACCESS
WARNING - Disconnect the dispenser from the power

source before the removal of any panel or the replace­ment of any component.

All components are accessible by opening the
door, removal of the door panels, dispenser top cov­ers, hoppers, hopper support plate, splash guard,
splash panel with drip tray, lower front access panel,
side and rear access covers.

for assistance in determining the

AUGER DRIVE COMPONENTS

J1

J2

J4

J3

Contents

Auger Drive Components...................................... 13

Auger Motor ......................................................... 16

Ballast ................................................................... 17

Control Board ....................................................... 18

Control Thermostat...............................................20

Dispense Switch ...................................................22

Fan........................................................................23

Frother ................................................................. 24

Hot/Cold Switch .................................................... 26

Increase/Decrease Switch..................................... 27

Lamp Holder ......................................................... 28

Lamp .................................................................... 28

Lamp Starter and Socket ...................................... 29

Limit Thermostat .................................................. 30

Overflow Protection Switch .................................. 31

Rinse/Run Switch .................................................32

Solenoid (Cold Drink - Optional) ........................... 33

Solenoid (Dispense) ............................................. 34

Solenoid (Inlet) ..................................................... 35

Tank Heater .......................................................... 36

Tank Heater Switch ............................................... 38

Transformer..........................................................39

Whipper Motor ..................................................... 25

Wiring Diagrams.......................................... 40 & 41

FIG. 1 AUGER DRIVE COMPONENTS

P1637.40

13

SERVICE

AUGER DRIVE COMPONENTS (CONT.)

14. Install hopper assy (20) in the dispenser by sliding

hopper assy in the guides on the hopper support

plate (19) until the slot in the bottom rear the

hopper seats against the shoulder screw (18) in

the hopper support plate.

Removal, Cleaning and Replacement:
Hopper & Auger (Late Models):

1. Open the dispenser door and raise the top front

cover.

2. Lift the front edge of hopper assy (17) over the

tab on hopper support plate (16) and slide hop-

per assembly out the front of the dispenser.

3. Remove hopper lid (1) and empty product.

4. Pull off the ejector elbow (10).

5. Remove agitator disk assy (2) by pushing out on

the side of the hopper, rotating the agitator disk

assy out of the mounting hubs and lifting the agi-

tator disk assy from the hopper. Remove the mix-

ing blades (4) from the agitator disk by tugging

sharply.

6. Remove auger (9) by pulling it out the front of the

hopper (8).

7. Remove the auger drive bracket by turning it clock-

wise whilde holding the auger drive shaft firmly.

8. Slide auger drive shaft (5) from auger drive shaft

bushing (3) and remove from hopper (8).

9. Remove locknut (7) from auger drive shaft bush-

ing (3) and remove auger drive shaft bushing from

hopper (8).

10. Wash components in a mild solution of dish de-

tergent using a bristle brush when needed.

11. Rinse and dry each item thoroughly.

12. Check for damaged or broken components, re-

place any if necessary and reassemble hopper

assembly.

13. Install hopper assy (17) in the dispenser by sliding

hopper assy in the guides on the hopper support

plate (16) until the slot in the bottom rear the

hopper seats against the shoulder screw (15) in

the hopper support plate.

1
2

4

3
5

6

7

8

9 10

Late Models

17

12 13 14 11 15 16

FIG. 3 AUGER DRIVE & HOPPER DISASSEMBLY

1. Hopper Lid

2. Agitator Disk Assy

3. Auger Drive Shaft
Bushing

4. Mixing Blade

5. Auger Drive Shaft

6. Auger Drive Bracket

7. Locknut

8. Hopper

9. Auger Wire

10. Ejector Elbow

11. Auger Motor Mount­ing Panel

12. Auger Motor Bracket

13. Auger Motor

14. Dust Seal

15. Shoulder Screw

16. Hopper Support plate

17. Hopper Assembly

P2210.30

15

29170 080900

SERVICE (cont.)

AUGER DRIVE COMPONENTS (cont.)

Auger Drive Motor (Refer to Fig. 2 & 3):

1. Remove all hopper assemblies (20,17) and set
aside for reassembly.

2. Remove the four #8-32 screws securing the hop­per support plate (19,16), remove plate and set
aside for reassembly.

3. Remove the four #8-32 locking screws, located
inside the dispenser housing on the front of the
auger motor mounting panel (14,11), securing
auger motor mounting bracket (15,12) and auger
motor (16,13) to the rear of the auger motor
mounting panel (14,11).

4. Disconnect the wires from the auger motor (16,13)
to be removed.

5. Remove auger motor mounting bracket (15,12),
auger motor (16,13) and dust seal (17,14) as an
assembly.

6. Remove dust seal (17,14) from auger motor
(16,13).

7. Remove the four #8-32 screws securing the auger
motor to the auger motor mounting bracket.

8. Remove auger motor and discard.

9. Using four #8-32 screw install new auger motor
(16,13) on mounting bracket (15,12).

10. Install dust seal (17,14) on auger motor shaft.

11. Using four #8-32 locking screws install auger
motor, dust seal and mounting bracket to the rear
of the auger motor mounting panel (14,11)

12. Reconnect the wires to the terminals on the auger
motor.

13. Install hopper support plate (19,16) and all hopper
assemblies (20,17).

14. Refer to Fig. 4 when reconnecting wires.

LEFT

BLK to GRN from
Control Board J3-4

RED to WHI/RED to
Control Board J3-3

CENTER RIGHT

RED to WHI/ORN to
Control Board J3-2

BLK to GRN from
Control Board J3-4

FIG. 4 AUGER MOTOR TERMINALS

RED toWHI/
BLU to
Control
Board J3-1

BLK to GRN from
Control Board J3-4

P1639

16

29170 080900

SERVICE (cont.)

BALLAST

Removal and Replacement:

1. Disconnect the wires from the ballast.

2. Remove the two #8-32 screws securing the bal-

last to the component bracket.

3. Remove and discard ballast.

4. Install new ballast using two #8-32 screws to se-

cure ballast to the component bracket..

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

BLK to Main Wiring
Harness

BLK to BLU
from Door

J1

J2

J4

J3

Interconnect
Harness

FIG. 5 BALLAST

P1637.40

Location:

The front door lamp ballast is located behind the
front access panel on the left side of the component
bracket.

Test Procedure:

1. Disconnect the dispenser from the power source.

2. Disconnect the two black leads on the ballast from

the door interconnect harness and the dispenser

main harness.

3. Check for continuity between the two black leads

on the ballast.

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

FIG. 6 BALLAST TERMINALS

P1447

17

SERVICE (cont.)

CONTROL BOARD

J1

J2

J4

J3

FIG. 7 CONTROL BOARD

Location:

The Control Board is located behind the lower front

access cover mounted on the component bracket.

Test Procedure:
Liquid Level Control Circuitry:

1. Disconnect the dispenser from the power source.

2. Disconnect the six pin connector from J3 of the
control board.

3. With a voltmeter, check the voltage across pins 5
& 6 of the six pin connector on the wiring harness.
Connect the dispenser to the power source. The
indication must be 24 volts ac.

4. Disconnect the dispenser from the power source.

P1637.40

6. Disconnect the four pin connector from J4 of the
control board.

7. With a voltmeter, check the voltage across pins 1
& 4 of the four pin connector on the wiring
harness. Connect the dispenser to the power
source. The indication must be:
a) 120 volts ac for two wire 120 volt models, three
wire 120/208 volt and 120/240 volt models.
b) 240 volts ac for two wire 240 volt models.

8. Disconnect the dispenser from the power source.

If voltage is present as described, proceed to step 9.
If voltage is not present as described, refer to the

Wiring Diagrams

and check the dispenser wiring har-

ness.

9. Reconnect the four pin connector of the wiring
harness to J4 of the control board.

10. Disconnect the ten pin connector from J2 of the
control board.

11. Carefully connect a piece of insulated jumper wire
to pin 10 (top right) of J2 on the control board.
Keep the other end of this wire away from any
metal surfaces of the dispenser.

12. With a voltmeter, check the voltage across the
terminals of the inlet solenoid valve. Connect the
dispenser to the power source. The indication
must be:
a) 120 volts ac for two wire 120 volt models, three
wire 120/208 volt and 120/240 volt models.
b) 240 volts ac for two wire 240 volt models after
a delay of approximately 10 seconds.

13. Touch the free end of the jumper wire to the
dispenser housing. The indication must be 0.

14. Move the jumper wire away from the housing. The
indication must, again, be:
a) 120 volts ac for two wire 120 volt models, three
wire 120/208 volt and 120/240 volt models.
b) 240 volts ac for two wire 240 volt models after
a delay of approximately 5 seconds.

15. Disconnect the dispenser from the power source
and remove the jumper wire.

If voltage is present as described, proceed to step 5.
If voltage is not present as described, refer to the

Wiring Diagrams

and check the dispenser wiring har-

ness.

5. Reconnect the six pin connector of the wiring
harness to J3 of the control board.

If voltage is present as described, proceed to step 16.
If the voltage is not present as described, replace the
control circuit board.

16. Reconnect the ten pin connector of the wiring
harness to J2 of the control board.

18

29170 091598

SERVICE (cont.)

CONTROL BOARD (cont.)

17. Gently pull the liquid level probe out of the tank lid
and inspect for corrosion. Replace it if necessary.

18. Place the probe so that neither end is in contact
with any metal surface of the dispenser.

19. With a voltmeter, check the voltage across the
terminals of the inlet solenoid valve. Connect the
dispenser to the power source. The indication
must be:
a) 120 volts ac for two wire 120 volt models, three
wire 120/208 volt and 120/240 volt models.
b) 240 volts ac for two wire 240 volt models after
a delay of approximately 10 seconds.

20. Move the probe’s flat end to the dispenser hous­ing. The indication must be 0.

21. Move the probe’s flat end away from the housing.
The indication must, again, be:
a) 120 volts ac for two wire 120 volt models, three
wire 120/208 volt and 120/240 volt models.
b) 240 volts ac for two wire 240 volt models after
a delay of approximately 5 seconds.

22. Disconnect the dispenser from the power source.

If the voltage is present as described, re-install the
probe. The liquid level control circuitry is operating
properly.
If the voltage is not present as described, check the
pink probe wire and green tank wire for continuity.

5. Reconnect the six pin connector of the wiring
harness to J3 of the control board.

6. Check that the rinse/run switch is in the run
position.

7. With a voltmeter, check the voltage across the red
(+) terminal and the black (-) terminal of the auger
motor. Connect the dispenser to the power source.
Press and hold the appropriate dispense switch.
After a delay of about .6 seconds, the indication
must be between +4.0 and +24.5 volts dc.

If the voltage is present as described, the hopper
motor control circuitry is operating properly.
If the voltage is not present as described, replace the
control circuit board.

Removal and Replacement:

1. Disconnect the three plugs on the main wiring
harness from the connectors on the control board.

2. Remove the four #6-32 keps nuts securing the
control board to the component bracket.

3. Remove control board and discard.

4. Install new control board on the component bracket
using four #6-32 keps nuts.

5. Reconnect the three plugs on the main harness to
the connectors on the control board.

Hopper Motor Control Circuitry:

1. Disconnect the dispenser from the power source.

2. Disconnect the six pin connector from J3 of the
control board.

3. With a voltmeter, check the voltage across pins 5
& 6 of the six pin connector on the wiring harness.
Connect the dispenser to the power source. The
indication must be 24 volts ac.

4. Disconnect the dispenser from the power source.

If voltage is present as described, proceed to step 5.
If voltage is not present as described, refer to the

Wiring Diagrams

and check the dispenser wiring har-

ness.

19

J2 J3

J2

J3

J4

J1

J1 J4

FIG. 8 CONTROL BOARD CONNECTORS

P1640

29170 091598

SERVICE (cont.)

CONTROL THERMOSTAT

FIG. 9 CONTROL THERMOSTAT

Location:

The control thermostat (mechanical or electronic)
is located inside the dispenser on the upper left side
of the housing.

Test Procedure:
Mechanical Thermostat:

1. Disconnect the dispenser from the power source.

2. Disconnect the black wire of the control thermo-

stat from the black lead from the limit thermostat.

3. Remove bulb from the tank.

4. With a voltmeter, check the voltage across black

wire on the control thermostat and the white or

red wire on the tank heater with the tank heater

switch in the “ON” (lower) position. Connect the

dispenser to the power source. The indication

must be:

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

b) 208 volts ac for three wire 120/208 volt mod-

els.

c) 240 volts ac for two wire 240 volt models and

three wire 120/240 volt models.

5. Disconnect the dispenser from the power source.

If voltage is present as described the control thermo­stat is operating properly. Reinstall bulb into the tank.
If voltage is not present as described, replace the
thermostat.

20

SERVICE (cont.)

CONTROL THERMOSTAT (cont.)

HI

HI

OFF

OFF

N

N

N

N

BU

BU

BLK from Limit

Thermostat
BLK from Tank
Heater Switch

MECHANICAL THERMOSTAT

HEATER

°

160

°

190

-
+

26527.0002

THERMOSTAT ASSEMBLY

BUNN-O-MATIC CORP

120VAC

®

TEMPERATURE

ADJUSTMENT

BLK to Main
Wiring Harness

ELECTRONIC THERMOSTAT

TAN to WHI/BRN in
Main Wiring Harness

BLK to Main
Wiring Harness

WHI to Main
Wiring Harness

FIG. 10 THERMOSTAT TERMINALS

P1448

21

29170 091598

SERVICE (cont.)

DISPENSE SWITCH

FIG.11 DISPENSE SWITCH

Location:

The dispense switches are located on the lower

outside of the dispenser door.
Test Procedure:

1. Disconnect the dispenser from the power source.

2. Open the dispenser door and remove the bottom
door cover.

3. Disconnect the wires from the door interconnect
wiring harness to the dispense switch to be tested.

4. Check for voltage across the black and red/black
wires for the right dispense switch, black and red/
white wires for the center dispense switch or the
black and red wires for the left dispense switch
from the door interconnect wiring harness. Con­nect the dispenser to the power supply. The indi­cation must be:
a) 120 volts ac for two wire 120 volt models, 120/
208 volt and 120/240 volt models.
b) 240 volts ac for two wire 240 volt models.

5. Disconnect the dispenser from the power source.

If voltage is present as described, proceed to #6.
If voltage is not present as described, refer to the

Wiring Diagrams

and check the dispenser wiring har-

ness.

P1631

If voltage is present as described, proceed to #7.
If voltage is not present as described, refer to the

Wiring Diagrams

and check the dispenser wiring har-

ness.

7. Check for continuity across the terminals (top
right to top left; bottom right to bottom left) of the
dispense switch with the switch in the “ON” posi­tion. Continuity must not be present when the
switch is in the “OFF” (released) position.

If continuity is present as described, reconnect the
connector to the door interconnect wiring harness,
the switch is operating properly.
If continuity is not present as described, replace the
switch.

Removal and Replacement:

1. Open the dispenser door.

2. Remove the five #6-32 screws securing the bot­tom door cover and remove cover.

3. Disconnect the wires on the dispense switch to
be removed from the door interconnect wiring
harness.

4. Compress the clips inside the door on the dis­pense switch and gently push the switch through
the opening.

5. Push new switch into the opening and spread the
clips to hold the switch in the door.

6. Reconnect the wires to the dispense switch from
door interconnect wiring harness.

7. Reinstall the door bottom cover using five #6-32
screws.

8. Refer to Fig. 12 when reinstalling wires.

BLK
RED/BLK

BLK
RED/WHI

6. With a voltmeter, check the voltage across the
blue/black (+) and orange (-) wires for the right
dispense switch, black/white (+) and orange (-)
wires for the center dispense switch, or blue/white
(+) and orange (-) for the left dispense switch from
the door interconnect wiring harness. Connect the
dispenser to the power source. The indication
must be +5 volts dc.

22

BLK
RED

CENTER

ORN

BLK/WHI

LEFT

ORN

BLU/WHI

FIG. 12 DISPENSE SWITCH TERMINALS

RIGHT

ORN

BLU/BLK

P1449

29170 080900

SERVICE (cont.)

FAN

J1

J2

J4

J3

FIG. 13 FAN

P1436

Location:

The fan is located inside the dispenser housing

on the right rear of the dispenser base plate.

Test Procedures:

1. Disconnect the dispenser from the power source.

2. Disconnect the black and white wires from the

fan terminals.

3. With a voltmeter, check the voltage across the

black and white wires. Connect the dispenser to
the power source. The indication must be:
a) 120 volts ac for two wire 120 volt, three wire
120/208 volt and 120/240 volt models.
b) 240 volts ac for two wire 240 volt models.

If voltage is present as described, replace the fan.
If voltage is not present as described, refer to

Diagrams

and check the dispenser wiring harness.

Wiring

23

24

SERVICE (cont.)

FROTHER AND WHIPPER MOTOR (cont.)

ward and at the same time twisting it clockwise.

6. Pull the mixing chamber (2) out of the whipper

chamber (4).

7. Remove the two #4-40 screws securing the fan

baffle(13) to the whipper motor mouting panel and
remove fan baffle. Set aside for reassembly.

8. Remove dispense tip (3) and twist the whipper

chamber (4) clockwise and pull it off the whipper
chamber receptacle (8).

9. Pull the frother (6) off the motor shaft. Notice the

flat side on the shaft and the matching flat inside
the frother. It is important that these two flats are
lined up when reassembling.

10. Slip the o-ring (5) off the whipper chamber recep-

tacle (8).

11. Remove the two nuts (7) securing whipper cham-

ber receptacle (8) and whipper motor (10) to the
front panel.

NOTE: To remove the recptacle only, rotate clockwise

until the receptacle clears the nuts (7) and slides
off of the motor shaft.

12. Slide the receptacle with seal off of the motor

shaft.

13. Slide the slinger (9) off of the motor shaft.

14. Disconnect the black leads on the motor (10) from

the main wiring harness.

15. Remove motor and discard.

16. Install new motor (10) on rear of front panel and

secure with two nuts (7) and connect black leads
on the motor to the main wiring harness. Refer to
Fig. 17 when reconnecting wires

17. Slide slinger (9) onto the motor shaft flush against

the front panel.

18. Wash remaining components in a mild solution of

dish detergent using a bristle brush.

19. Rinse thoroughly and allow to dry before reinstall-

ing in the dispenser.

20. Slide whipper chamber receptacle with seal (8)

and o-ring (5) on to the motor shaft.

21 Rotate the receptacle with seal (8) counterclock-

wise until it snaps into place on the motor mount­ing nuts (7).

22. Push frother (6) onto the motor shaft, making sure

the flat in the frother (6) lines up with the flat on the
motor shaft.

23. Install whipper chamber (4) on the whipper cham-

ber receptacle (8) by twisting counterclockwise
until the tabs on the whipper chamber (4) lock with
the tabs on the whipper chamber receptacle (8).
Be sure dispense port is pointing down.

24. Install dispense tip (3) into the bottom of the
whipper chamber (4).

25. Using two #4-40 screws secure the fan baffle to
the whipper motor mounting panel.

26. Install vacuum hose (12) on fan baffle (13).

27. Install hopper support panel using four #8-32
screws.

28. Slip the mixing chamber (2) onto the mixing
chamber water inlet tube far enough so the mixing
chamber (2) will seat inside the whipper chamber
(4).

29. Install the steam collector (1) onto the mixing
chamber (2) by pushing down and toward the
dispenser while twisting until the flange on the
steam collector lines up with the slot in the front
panel.

30. Install hopper assembly in the dispenser by sliding
hopper assembly on the hopper support panel
until the slot in the bottom rear of the hopper seats
against the shoulder screw in the hopper support
panel.

RIGHT

CENTER

LEFT

BLK to Main Harness ORA
BLK to Main Harness WHI

BLK to Main Harness RED
BLK to Main Harness WHI

FIG.17 WHIPPER MOTOR TERMINALS

BLK to Main
Harness WHI/VIO
BLK to Main
Harness WHI

P1451.40

25

29170 091598

SERVICE (cont.)

HOT/COLD SWITCH (Optional)

P1642.40

FIG. 18 HOT/COLD SWITCH

Location:

The hot/cold switch is located on the left side of

the whipper motor mounting panel.

Test Procedure:

1. Disconnect the dispenser from the power source.

2. Disconnect the four pin plug from the hot/cold
switch and the four pin connector on the main
wiring harness.

3. Press the left dispense switch on the door and,
with a voltmeter, check the voltage across the
white wire (pin 4) and red wire (pin 2) in the four
pin connector on the main wiring harness. Con­nect the dispenser to the power source. The indi­cation must be:
a) 120 volts ac for two wire 120 volt models, and
three wire 120/208 volt and 120/240 volt models.
b) 240 volts ac for two wire 240 volt models.

4. Disconnect the dispenser from the power source.

If voltage is present as described, reconnect the four
pin plugs and proceed to #5.
If voltage is not present as described, refer to the

Wiring Diagrams

and check the main wiring harness.

5. Disconnect the wires from the switch terminals.

6. With the switch in the “Cold” (upper) position
check for continuity between the center terminal
and the bottom terminal. With the switch in the
“Hot” (lower) position check for continuity be­tween the center terminal and the upper terminal.

If continuity is present as described, the hot/cold
switch is operating properly.
If continuity is not present as described, replace the
switch.

Removal and Replacement:

1. Remove all wires from the switch terminals.

2. Remove the mounting nut on the front of the whip­per motor mounting panel.

3. Remove the hot/cold switch from the rear of the
front panel and discard.

4. Reconnect the wires to the terminals on the rear
of the new switch.

5. Push new hot/cold switch through the hole on the
left side of the whipper motor mounting panel and
secure with mounting nut.

6. Refer to Fig. 19 when reconnecting the wires.

TAN to Main Harness

RED to Main Harness

WHI/YEL to Cold
Solenoid

FIG. 19 HOT/COLD SWITCH TERMINALS

P1208

26

29170 080900

SERVICE (cont.)

INCREASE/DECREASE SWITCH

Removal and Replacement:

1. Open the dispenser door.

2. Remove the facenut securing the increase/de­crease switch the whipper motor mounting panel.

3. Remove switch with wires attached from the back
side of the whipper motor mounting panel.

4. Disconnect the wires from the switch and discard
the switch.

5. Refer to Fig. 21 when connecting the wires to the
new switch.

6. Install new switch with wires attached through the
hole in the whipper mounting panel and secure
with facenut.

RED/BLK from Control
Board J2-6
GRN from Control
Board J2-9
BRN/BLK from Control
Board J2-1

P1642.40

FIG. 20 INCREASE/DECREASE SWITCH

Location:

The increase/decrease switch is located on the

lower left front of the whipper motor mounting panel.

Test Procedure:

1. Disconnect the dispenser from the power source.

2. Disconnect the wires from the switch terminals.

3. Check for continuity between the center terminal
and upper terminal with switch in the decrease
(lower) position. Check for continuity between the
center terminal and the lower terminal with the
switch in the increase (upper) position. Continuity
must not be present when the switch is in the
center position.

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

FIG. 21 INCREASE/DECREASE SWITCH

TERMINALS

P1208

27

29170 091598

SERVICE (cont.)

LAMP HOLDER

1

3

5

4

2

6

FIG. 22 LAMP HOLDERS

1. Door Assy

2. Lamp Holders

3. Lamp

4. Upper Panel

5. Lower Panel

6. Starter W/Socket

P1643.70

Location:

The lamp holders are located on the front of the

upper panel behind the display panel.

Test Procedure:

1. Disconnect the dispenser from the power source.

2. Remove upper door panel (4) and disconnect the
door wiring harness from the leads on the lamp
holders.

3. Remove lamp from lamp holders.

4. Check for continuity on each lead of the lamp
holders.

If continuity is present as described, lamp holders are
operating properly.
If continuity is not present as described replace the
lamp holder.

Removal and Replacement:

1. Open dispenser door (1).

2. Remove the five #6-32 screws securing lower
door panel (5) to the door (1) and remove cover.

3. Disconnect the door wiring harness from the door
interconnect wiring harness.

4. Remove five #6-32 screws securing the upper
door panel (4) to the door (1).

5. Remove the upper door cover (4), lamp (3), lamp
holders (2) and door wiring harness as an assem­bly.

6. Disconnect the wires from the lamp holder to be
replaced from the door wiring harness.

7. Rotate lamp (3) 90° and remove from lamp hold­ers (2).

8. Remove the #6-32 screw securing the lamp holder
(2) to be removed, remove lamp holder (2) and
discard.

9. Install new lamp holder (2) and secure with a #6­32 screw.

10. Connect the wires on the new lamp holder to the
door wiring harness.

11. Install lamp (3) into lamp holders (2) and turn 90°
until the pins snap in place.

12. Install upper door panel (4), lamp (3), lamp hold­ers (2) and door wiring harness as an assembly
using five #6-32 screws.

13. Reconnect the plug on the door wiring harness to
the connector on the door interconnect wiring
harness.

14. Install the door lower panel (5) using five #6-32
screws.

LAMP REPLACEMENT (Refer to Fig. 22)

1. Remove the outside window and display graphic.

2. Remove the two #4-40 screws securing the inside
window to the door and remove window.

3. Rotate lamp (3) 90° and remove from the lamp
holders (2).

4. Insert new lamp (3) into lamp holders (2) and turn
90° until the pins snap in place.

5. Using two #4-40 screws secure the inside window
to the door.

6. Install outside window and slide display graphic
down between the inside window and the outside
window.

28

29170 091598

SERVICE (cont.)

LAMP STARTER and SOCKET

Location:

The lamp starter (6) is located inside the door assy

(1) on the top of the door lower panel (5).

Test Procedures:

1. Disconnect the dispenser from the power source.

2. Disconnect the starter leads from the door wiring
harness.

3. Remove lamp starter from starter socket.

4. Check for continuity on each lead of the starter
socket.

If continuity is present as described the starter socket
is operating properly.
If continuity is not present as described replace the the
starter socket.

6. Remove starter (6) from starter socket.

7. Check for continuity across the pins on the bottom
of the starter (6).

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

Removal and Replacement (Refer to Fig.22):

1. Open dispenser door assy (1)

2. Remove the five #6-32 screws securing the door
lower panel (5) to the door assy (1).

3. Disconnect the leads on the starter socket from the
door wiring harness.

4. Remove lower door panel (5) and starter w/socket
(6) as assembly.

5. Compress the spring tabs on the socket and re­move socket from the door bottom cover (5).

6. Rotate starter 90° and remove from the starter
socket.

7. Insert new starter (6) into socket and turn 90° until
the pins snap in place.

8. Install new socket by compressing spring tabs on
the socket and pushing the socket up through the
hole in the lower door panel (5) and releasing
spring tabs.

9. Connect the sockets leads to the door wiring
harness.

10. Install door lower panel (5) with starter and starter
socket on door assy (1) using five #6-32 screws.

Note: If continuity tests are both as described and
lamp does not light, replace the starter socket.

29

29170 080900

BLK to Tank

BLK to Control

Heater

Thermostat

FIG. 24 LIMIT THERMOSTAT TERMINALS

P1800

30

31

SERVICE (cont.)

RINSE /RUN SWITCH

Removal and Replacement:

1. Open the dispenser door.

2. Remove the facenut securing the run/rinse switch
to the whipper motor mounting panel.

3. Remove switch with wires attached from the back
side of the whipper motor mounting panel.

4. Disconnect the wires from the switch and discard
the switch.

5. Refer to Fig. 28 when connecting the wires to the
new switch.

6. Install new switch with wires attached through the
hole in the whipper motor mounting panel and se­cure with facenut.

FIG. 27 RINSE/RUN SWITCH

P1452.40

Location:

The rinse/run switch is located on the lower right

side of the whipper motor mounting panel.

Test Procedures:

1. Disconnect the dispenser from the power source.

2. Check for continuity between the center left ter­minal and left bottom terminal, also between the
center right terminal and the right bottom termi­nal with the switch in the rinse (upper) position.
Check for continuity across the center left termi­nal and the top left terminal, also between center
right right terminal and the right top terminal with
the switch in the run (lower) position . Continuity
must not be present when the switch is in the
center position.

WHI/BRN to
Door Harness

GRY to Control
Board J2-2

GRN to Control
Board J2-9

BLK from
Main Harness

WHI/BRN to
Door Harness

YEL to Control

Board J2-3

FIG. 28 RINSE/RUN SWITCH TERMINALS

P1644

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

32

29170 091598

SOLENOID VALVE (COLD WATER - OPTIONAL)

COLD" switch in the "COLD" (upper) position press
the left dispense switch and listen carefully in the
vicinity of the solenoid valve for a "clicking" sound
as the coil magnet attracts.

7. Disconnect the dispenser from the power source.

J1

J2

J4

J3

P1637.40

FIG. 29 COLD WATER SOLENOID VALVE

Location:

The cold water solenoid valve is located on the
left side of the dispenser base just behind the compo­nent bracket.

Test Procedures:

1. Disconnect the dispenser from the power source.

2. Disconnect the white and white/yellow wires from

the solenoid valve. With the “HOT/COLD” switch in

the "COLD" (upper) position press the left dis-

pense switch on front of the door.

3. With a voltmeter, check the voltage across the

white and white/yellow wires. Connect the dis-

penser to the power source. The indication must

be:

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

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

b) 240 volts ac for two wire 240 volt models.

4. Disconnect the dispenser from the power source.

If voltage is present as described, proceed to #5
If voltage is not present as described, refer to

Diagrams

and check dispenser wiring harness.

Wiring

If the sound is heard as described and water will not
pass through the solenoid valve, there may be a block­age in the water line before the solenoid valve or, the
solenoid valve may require inspection for wear, and
removal of waterborne particles.

If the sound is not heard as described, replace the
solenoid valve.

Removal and Replacement:

1. Loosen the two screws securing the component
bracket to the dispenser base. Lift the component
bracket off of the base and move to the right.

2. Remove the white and white/yellow wires from
the solenoid valve.

3. Turn off the water supply to the dispenser.

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

5. Loosen the two #8-32 screws and washers se­curing the solenoid mounting bracket to the base.
Remove solenoid bracket and solenoid valve as
an assembly.

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

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

8. Install the solenoid valve and bracket on the dis­penser base and tighten the two #8-32 screws.

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

10. Refer to Fig. 30 when reconnecting the wires.

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

If continuity is present as described, reconnect the
white and white/yellow wires to the solenoid.

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

6. Check the solenoid valve for coil action. Connect
the dispenser to the power source. With "HOT/

33

SERVICE (cont.)

SOLENOID VALVES (DISPENSE)

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

6. Check the solenoid valve for coil action. Connect
the dispenser to the power source. With "RUN/
RINSE" switch in the "RINSE" (upper) position
press the appropriate dispense switch and listen
carefully in the vicinity of the solenoid valve for a
"clicking" sound as the coil magnet attracts.

7. Disconnect the dispenser from the power source.

If the sound is heard as described and water will not
pass through the solenoid valve, there may be a block­age in the tank water outlet before the solenoid valve
or, the solenoid valve may require inspection for wear,
and removal of waterborne particles.

If the sound is not heard as described, replace the
solenoid valve.

P1637.40

FIG. 31 DISPENSE SOLENOID VALVES

Location:

The dispense solenoids are located on the upper

left side of the tank.

Test Procedures:

1. Disconnect the dispenser from the power source.

2. Disconnect the white and white/violet, orange or
tan wires from the solenoid valve. With the “RUN/
RINSE” switch in the "RINSE" (upper) position
press the appropriate dispense switch on front of
the door.

3. With a voltmeter, check the voltage across the
white and white/violet, orange or tan wires. Con­nect the dispenser to the power source. The indi­cation must be:
a) 120 volts ac for two wire 120 volt models, three
wire 120/208 volt, and 120/240 volt models.
b) 240 volts ac for two wire 240 volt models.

4. Disconnect the dispenser from the power source,

If voltage is present as described, proceed to #5
If voltage is not present as described, refer to

Diagrams

and check dispenser wiring harness.

Wiring

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

If continuity is present as described, reconnect the
white and white/violet, orange or tan wires to the so­lenoid.

Removal and Replacement:

1. Remove the white and white/violet,orange or tan
wires from the solenoid valve.

2. Turn off the water supply to the dispenser.

3. Drain enough water from the tank (approximately

1.0 gallon) so the water level is below the dispense
valve mounting hole.

4. Disconnect the water line from the solenoid valve.

5. Remove the #10-32 screw securing the solenoid
valve to side of the tank. Remove solenoid valve.

6. Using the #10-32 screw install new solenoid valve
on side of the tank

7. Push the water line onto the tube on bottom of
solenoid valve.

8. Refer to Fig. 32 when reconnecting the wires.

TAN to Main Harness
WHI to Main

LEFT

CENTER

Harness
ORN to Main
Harness
WHI to Main
Harness
WHI/VIO to Main
Harness
WHI to Main
Harness

FIG. 32 DISPENSE SOLENOID VALVE

TERMINALS

34

RIGHT

P1645

29170 080900

J1

J2

J4

J3

35

SERVICE (cont.)

TANK HEATER

FIG. 35 TANK HEATER

P1637.40

Location:

The tank heater is located inside the tank and se-

cured to the tank lid.

Test Procedure:

1. Disconnect the dispenser from the power source.

2. With a voltmeter, check the voltage across the
black and white wires 120 volt or 240 volt models
or black and red wires for 120/208 volt models or
120/240 volt models. Connect the dispenser to the
power source. The indication must be:
a) 120 volts ac for two wire 120 volt models;
b) 208 volts ac for three wire 120/208 volt models.
c) 240 volts ac for three wire 120/240 volt models
and two wire 240 volt models.

3. Disconnect the dispenser from the power source.

If voltage is present as described, proceed to #4.
If voltage is not present as described, refer to the
dispenser

Wiring Diagrams

and check the wiring har-

ness.

36

SERVICE (cont.)

TANK HEATER (cont.)

WHI or RED to
Main Wiring
Harness

FIG. 36 TANK HEATER TERMINALS

BLK to Limit
Thermostat

P1218

37

29170 080900

SERVICE (cont.)

TANK HEATER SWITCH

FIG. 37 TANK HEATER SWITCH

P1642.40

Location:

The tank heater switch is located inside the dis-

penser on the upper right of the whipper motor mount­ing panel.

Test Procedure:

BLK from Main Harness
(Mechanical Thermostat)
WHI/BRN from Main Harness
(Electronic Thermostat)

BLK from Main Harness
(Mechanical Thermostat)
WHI/BRN from Main Harness
(Electronic Thermostat)

P1208

FIG. 38 TANK HEATER SWITCH TERMINALS

38

29170 091598

SERVICE (cont.)

TRANSFORMER

If voltage is not present as described, refer to the

Wiring Diagrams

and check the main wiring harness.

5. Check the voltage between J3-5 and J3-6 on the
six pin connector at the control board. Connect the
dispenser to the power source. The indication
must be 24 volts ac.

If voltage is present as described the transformer is
operating properly.
If voltage is not present as described, replace the
transformer.

Removal and Replacement:

1. Loosen the two #8-32 screws securing the com­ponent bracket to the dispenser housing base.

2. Pull component bracket out the front of the dis­penser far enough so the transformer connector
can be disconnected from the main wiring har­ness.

3 Disconnect the transformer four pin connector

from the four pin plug on the main wiring harness.

4. Remove the two #6-32 keps nuts securing the
transformer to the rear of the component bracket.

5. Remove and discard the transformer.

6. Install new transformer on the rear of the compo­nent bracket and secure with two #6-32 keps nuts.

7. Connect the four pin connector on the transformer
to four pin plug on the main wiring harness.

8. Place the component bracket into position and
tighten the two #8-32 screws.

WHI/GRN - T8

WHI/BLK - T12

39

WHI - 120V T2, 240V T6

BLK - TI

P1647

FIG. 40 TRANSFORMER TERMINALS

29170 080900

40

29170 091598

SCHEMATIC WIRING DIAGRAM FMDA-3

L1

GRN

L2

C
O
N
T
R
O
L

P

.

C

B
O
A
R
D

.

J4-1

J4-4

J3-1

J3-5

J2-1

J2-5

J2-10

GRN

PROBE

WHI

VIO

WHI

BLU

WHI/BLU
WHI/ORN
WHI/RED
GRN
WHI/GRN
WHI/BLK

BRN/BLK
GRY
YEL
WHI/ORN
WHI/YEL
RED/BLK
WHI/RED

WHI/BLU
GRN
PNK

BLK-16

BLK

BLK

BLK

BLK

BLK

GRN

TANK HEATER

SWITCH

BLK

BLK

CONTROL

THERMOSTAT

BLK-16

OVERFLOW SWITCH

RED RED

FLUORESCENT

LAMP

BALLAST

BLK

BLK

BRN/BLK

BLK-16

BLU

GRN

I
N
C

RED/BLK

LIMIT

THERMOSTAT

BLK-16 BLK-16

WHI

WHI

WHI/BLK

WHI

INCREASE/

D

E

DECREASE

C

SWITCH

4

1

WHI/BLK
WHI/GRNWHI/GRN

WHI

BLKBLK

TANK HEATER

GRY

YEL

WHI/BRN

WHI/BRN

240V : 24V AC

TRANSFORMER

WHI/BLK

WHI/GRN

WHI

RINSE/PROGRAM/

RUN SWITCH

RUN

PGM

RINSE

RUN

PGM

RINSE

BLK

GRN

BLK

BLK

VIO

FAN

TANK INLET

SOL

GRN

WHI-16

WHI

WHI

WHI

WHIWHI

GRY

PNK

"RINSE" L.E.D.

1

GRN/BLK

WHI/BLK

ORN

BLK

RIGHT DISPENSE

SOL

CENTER DISPENSE

SOL

LEFT DISPENSE

TAN

SOL

WHI

WHI

WHI

WHI/VIOWHI/VIO

ORNORN

RED

RIGHT WHIPPER

M

CENTER WHIPPER

M

LEFT WHIPPER

M

WHI

WHI

WHI

WHI/BLU

WHI/ORN

WHI/RED

RIGHT HOPPER

RED

M

CENTER HOPPER

RED

M

LEFT HOPPER

RED

M

BLK

BLK

BLK

GRN

GRN

GRN

ORN

WHI/VIO

WHI/ORN

1

GRN

WHI/BLU

ORN

BLU/BLK

BLK/WHI

WHI/RED

4

BLU/WHI

ORN

BLK

1

BLU

WHI

BLU

WHI

BLK/WHI
RED/WHI

1

ORN

WHI/VIO

RED/BLK

RED/WHI

WHI/BRN

BLK

ORN

BLK

WHI/YEL

GRN

1

BLU/WHI
RED

COLD DRINK OPTION (LEFT ONLY)

1

RED

RED

RED

RED

TAN

TAN

WHI

WHI

4

GRN

CHASSIS

4

RED

RED

DOOR

BLU/BLK
RED/BLK

HOT/COLD SWITCH

WHI

BLU

1

WHI/YEL

TAN

BLU
BLU

SOL

WHI

RED

JUMPER PLUG MUST BE

RED
RED

USED WHEN COLD

DRINK FEATURE NOT

INSTALLED

230 VOLTS A C - 2 WIRE 

SINGLE PHASE, 50 HZ



28874.0001C 8/98 © 1998 BUNN-O-MATIC CORPORATION

WHI

BLK

RED

BLK

STARTER

BLK

RED

BLK

WHI

LEFT DISPENSE SWITCH

CENTER DISPENSE SWITCH

RIGHT DISPENSE SWITCH

41

29170 080900