Bunn Coffee Maker TWF Installation Manual
®
BUNN
TW
TWF
OPERATING & SERVICE MANUAL
BUNN-O-MATIC CORPORATION
POST OFFICE BOX 3227
SPRINGFIELD, ILLINOIS 62708-3227
TELEPHONE: (217) 529-6601 FAX: (217) 529-6644
10510.0000 11/00 © 1990 Bunn-O-Matic Corporation
CONTENTS
Introduction ............................................................. 2
Warranty .................................................................. 2
User Notices ............................................................ 3
Electrical Requirements ........................................... 4
Plumbing Requirements .......................................... 4
Initial Set-Up............................................................ 5
Adjusting Brew Controls .......................................... 6
Cleaning................................................................... 6
Operating Controls................................................... 7
Tea Brewing ............................................................. 7
Troubleshooting ....................................................... 8
Service................................................................... 14
Wiring Diagram ..................................................... 31
INTRODUCTION
This equipment will brew a half-gallon batch of hot coffee into an airpot server or dispenser and a threegallon batch of fresh tea into a dispenser and dispense at approximately room temperature to conserve ice. The
brewer is only for indoor use 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 mate-
rial 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.
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10510 071000
USER NOTICES
Carefully read and follow all notices on the equipment and in this manual. They were written for your protec-
tion. All notices on the equipment should be kept in good condition. Replace any unreadable or damaged labels
#00656.0000
#00831.0000
#02822.0000
#03408.0000
#03409.0000
Page 3
10510 081599
ELECTRICAL REQUIREMENTS
CAUTION - The brewer must be disconnected from the power source until specified in
Initial Set-Up.
120V model brewers require 2-wire, grounded service rated 120 volt
ac, 15 amp, single phase, 60 Hz.
120/208V model brewers require 3-wire, grounded service rated 120/
208 volt, 20 amp, single phase, 60 Hz.
L2 RED
WHITE
NEUTRAL
L1 BLACK
120V.A.C.
208V.A.C.
120V.A.C.
Electrical Hook-Up
CAUTION – Improper electrical installation will damage electronic components.
1. An electrician must provide electrical service as specified.
2. Remove the top lid and rotate the control thermostat knob fully counterclockwise to the "OFF" position.
3. a) 120V brewers have an attached cordset. Plug in the brewer and proceed to #6.
b) 120/208V brewers, feed the cord through the strain relief at the rear of the brewer and connect it to the
terminal block.
4. Using a voltmeter, check the voltage and color coding of each conductor at the power source.
5. Connect the brewer to the power source and verify the voltage at the terminal block.
6. If plumbing is to be hooked up later be sure the brewer is disconnected from the power source. If plumbing
has been hooked up, the brewer is ready for
Initial Set-Up.
PLUMBING REQUIREMENTS
These brewers must be connected to a cold water system with operating pressure between 20 (128) and 90
psi (620 kPa) from a 1⁄2" or larger supply line. A shut-off valve should be installed in the line before the brewer.
Install a regulator in the line when pressure is greater than 90 psi (620 kPa) to reduce it to 50 psi (345 kPa). The
water inlet fitting is 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. A tight coil of copper tubing in the water line will facilitate moving the
brewer to clean the countertop. Bunn-O-Matic does not recommend the use of a saddle valve to install the
brewer. The size and shape of the hole made in the supply line by this type of device may restrict water flow.
1. Remove the shipping cap(s) from the bulkhead fitting(s) on the rear of the brewer.
2. Attach the flare fitting from the short piece of tubing on the strainer/flow control (supplied) to the water inlet
fitting(s) at the rear of the brewer.
3. Flush the water line and securely attach it to the flare fitting on the tee or strainer/flow control.
4. Turn on the water supply.
5. On brewers with a faucet, place an empty vessel beneath the faucet and lift the handle until water is dis-
pensed.
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).
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10510 071000
PLUMBING REQUIREMENTS (cont.)
BREWERS W/OUT FAUCET
P1394
BREWERS W/FAUCET
P1392
INITIAL SET-UP
CAUTION – The brewer must be unplugged throughout the initial set-up, except when specified in the instruc-
tions.
1. Remove the top lid from the brewer.
2. Rotate the control thermostat knob fully counterclockwise to the “OFF” position and replace the top lid.
3. Insert the funnel (empty) into the funnel rails.
4. Place an empty tea dispenser on the brewer base. Be prepared to empty the dispenser a few times.
5. Plug in the brewer, place the TEA/OFF/COFFEE switch in the “COFFEE” position, and momentarily press the
start switch. When the flow of water into the tank stops, press the START switch to initiate a second cycle.
Wait until the flow of water stops and start a third cycle. During the third cycle, the tank will fill to its capacity
and the excess will flow from the funnel into the dispenser. Empty the dispenser when this third cycle stops.
6. Place the TEA/OFF/COFFEE switch in the “TEA” position and begin another brew cycle.
7. Measure the total water volume from the dispenser. It should be approximately (396 ounces.)
8. If not, adjust the Iced Tea Brew Timer (right timer) as required. (See
9. Start, and measure another cycle.
10. Repeat steps 7-9 until the recommended total water volume (396 ounces) is achieved.
11. The concentrate valve is pre-adjusted to deliver the correct ratio of brew water to dilution water.
12. Unplug the brewer, remove the top lid, rotate the control thermostat knob fully clockwise to the “ON” position
and replace the top lid.
13. Empty the dispenser.
14. Plug in the brewer and wait for the water in the tank to heat to brewing temperature (approximately 20
minutes). Some water will drip from the funnel during this time; this is due to expansion and should not
occur thereafter.
15. Place the TEA/OFF/COFFEE switch in the “COFFEE” position and begin another brew cycle. Empty the reservoir after water has stopped flowing from the funnel.
16. Allow the water in the tank to heat to the proper temperature and begin another brew cycle.
17. Measure the total water volume from the dispenser. It should be approximately 64 ounces.
18. If not, adjust the Coffee Brew Timer (left timer) as required. (See
19. Start, and measure another cycle.
20. Repeat steps 17-19 until the recommended total water volume (64 ounces) is achieved.
21 The brewer is now ready to brew approximately one-half gallon of hot coffee or 3-gallons of freshly brewed
room temperature tea.
Page 5
Adjusting Brew Volume
Adjusting Brew Volume
)
)
10510 071000
INITIAL SET-UP (cont.)
ADJUSTING BREW VOLUMES
CAUTION - Disconnect the power source from the brewer prior to the removal of any panel for the replacement
or adjustment of any component.
NOTE: Prior to setting or modifying batch sizes, check that the brewer is connected to water supply, the tank is
properly filled, and a funnel and server are in place.
1. Modifying batch sizes. To modify a batch volume, first check that the SET/LOCK switch is in the “SET”
position on the circuit board.
To increase a batch size. Press and hold the START or BREW switch until three clicks are heard. Release the
switch (Failure to release the switch within two seconds after the third click causes the volume setting to be
aborted and previous volume setting will remain in memory) and press it again one or more times. Each time
the switch is pressed, two seconds are added to the brew time period. Allow the brew cycle to finish in order
to verify that the desired volume has been achieved.
To decrease a batch size. Press and release the START or BREW switch once for every two-second interval
to be removed from the total brew time period; then immediately press and hold down the START or BREW
switch until three clicks are heard. Release the switch. (Failure to release the switch within two seconds after
the third click causes the volume setting to be aborted and previous volume setting will remain in memory).
Allow the brew cycle to finish in order to verify that the desired volume has been achieved.
2. Setting batch sizes. To set a batch volume, first check that the SET/LOCK switch is in the “SET” position on
the circuit board. Press and hold the START or BREW switch until three distinct clicks are heard, and then
release the switch. (Failure to release the switch within two seconds after the third click causes the volume
setting to be aborted and previous volume setting will remain in memory). View the level of the liquid being
dispensed. When the desired level is reached, turn the ON/OFF switch to “OFF” (lower). The brewer remembers this volume and will continue to brew batches of this size until the volume setting procedure is repeated.
NOTE: When brewing coffee, batch volumes will decrease due to absorption by the coffee grounds.
3. Setting programming disable feature. If it becomes necessary to prevent anyone from changing brew times
once programmed, you can set the SET/LOCK switch to the “LOCK” position. This will prevent any programming to be done until switch is once again placed in the “SET” position.
CLEANING
CAUTION – Do not keep brewed tea overnight. Clean and sanitize your iced tea dispenser daily
1. Remove and thoroughly clean the brew funnel. The funnel tip and screen must be free from any tea particles
or residue. Reassemble the funnel.
2. Unplug the brewer. Remove and thoroughly rinse the sprayhead. The holes must be open and clear of any
mineral deposits. Wipe the sprayhead panel clean with a damp cloth.
3. Insert the deliming spring into the sprayhead fitting until no more than one inch is visible and move it in and
out 5 or 6 times. Insert the spring into the airvent hole in the sprayhead panel and move it in and out 5 or 6
times. Reattach the sprayhead.
4. Wash the entire outside surface of the brewer with a clean damp cloth.
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10510 071000
OPERATING CONTROLS
A. TEA/OFF/COFFEE Switch
TEA– Placing the switch in the left position allows the start switch to activate a timed brew cycle delivering .5
gallon of tea concentrate and 2.5 gallons of dilution water into the dispenser.
OFF – Placing the switch in the center position stops the brew cycle. Stopping a brew cycle after it has started
will not stop the flow of water into the funnel until the tank syphons down to its level. The switch should always
be placed in this position after a brew cycle and whenever the brewer is unattended.
COFFEE– Placing the switch in the right position allows the start switch to activate a timed brew cycle delivering
.5 gallon of hot coffee into an airpot dispenser.
B. Start Switch
Starts a brew cycle when the TEA/OFF/COFFEE switch is in either the “TEA” or “COFFEE” position.
BREWING
1. Begin brewing with a clean empty brew funnel and dispenser. (Be sure the server lid doesn't interfere with
the flow of dilution water)
2. Insert a BUNN® filter into the funnel.
3. Pour the packet of fresh tea leaves or coffee into the filter. Approximately 4 ounces is recommended for tea.
4. Level the bed of tea leaves or coffee by gently shaking.
5. Slide the funnel into the funnel rails until it stops.
6. Place the TEA/OFF/COFFEE switch in the desired position.
7. Momentarily press the start switch.
CAUTION – The funnel contains hot liquid. Remove funnel slowly.
8. Carefully remove the brew funnel and discard its contents after liquid stops flowing from the funnel.
9. Place the TEA/OFF/COFFEE switch in the “OFF” position to prevent a false start.
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10510 071000
TROUBLESHOOTING
A troubleshooting guide is provided to suggest probable causes and remedies for the most likely problems
encountered. If the problem remains after exhausting the troubleshooting steps, contact the Bunn-O-Matic
Technical Service Department.
• Inspection, testing, and repair of electrical equipment should be performed only by qualified service personnel.
• All electronic components have 120 volt ac and low voltage dc potential on their terminals. Shorting of
terminals or the application of external voltages may result in board failure.
• Intermittent operation of electronic circuit boards is unlikely. Board failure will normally be permanent. If an
intermittent condition is encountered, the cause will likely be a switch contact or a loose connection at a
terminal or crimp.
• Solenoid removal requires interrupting the water supply to the valve. Damage may result if solenoids are
energized for more than ten minutes without a supply of water.
• The use of two wrenches is recommended whenever plumbing fittings are tightened or loosened. This will
help to avoid twists and kinks in the tubing.
• Make certain that all plumbing connections are sealed and electrical connections tight and isolated.
• This brewer is heated at all times. Keep away from combustibles.
WARNING –
• Exercise extreme caution when servicing electrical equipment.
• Unplug the brewer when servicing, except when electrical tests are specified.
• Follow recommended service procedures
• Replace all protective shields or safety notices
Problem
Brew cycle(s) will not start
Probable Cause
1. No water
2. No power or incorrect voltage to
the brewer
3. External Strainer/ Flow Control
(.750 GPM)
4. TEA/OFF/COFFEE Switch
5. Start Switch
Remedy
Water lines and valves to the brewer
must be open.
Check circuit breakers or fuses.
(A) Direction of flow arrow must be
pointing towards the brewer.
(B) Remove the strainer/flow control and check for obstructions.
Clear or replace.
Refer to
Service
- TEA/OFF/COFFEE
Switch for testing. See page 26
Refer to
Service
- Start Switch for
testing procedures. See page 27
Page 8
10510 071000
TROUBLESHOOTING (cont.)
PROBLEM
Brew cycle(s) will not start (cont.)
PROBABLE CAUSE
6. Brew Timer
A) Iced Tea
B) Hot Coffee
7. Brew Solenoid Valve
A) Iced Tea
B) Hot Coffee
8. Internal Flow control (.195 GPM)
(Hot Coffee Only)
REMEDY
Refer to
Service
- Brew Timer (Iced
Tea) for testing procedures. See
page 20 or 21
Refer to
Service
- Brew Timer (Hot
Coffee) for testing procedures. See
page 17 or 18
Refer to
Service
- Brew Solenoid
Valve (Iced Tea) for testing procedures. See page 16
Refer to
Service
- Brew Solenoid
Valve (Hot Coffee) for testing procedures. See page 15
(A) Direction of flow arrow must be
pointing towards brewer.
Brew water is not hot
1. Limit Thermostat
CAUTION - Do not eliminate or bypass limit thermostat. Use only
BOM replacement part
#29329.1000
2. Thermal Fuse
CAUTION - Do not eliminate or bypass thermal fuse.
3. Control Thermostat
4. Tank Heater
(B) Remove the flow control and
check for obstructions. Clear or replace.
Refer to
Service
- Limit Thermostat
for testing procedures. See page 25
Refer to
Service
- Thermal fuse for
testing procedures. See page 29
Refer to
Service
- Control Thermostat for testing procedures. See
page 23
Refer to
Service
- Tank Heater for
testing procedures. See page 28
Dilution (Iced Tea) cycle will not
start
1. TEA/OFF/COFFEE Switch
Page 9
Refer to
Service
- TEA/OFF/COFFEE
Switch for testing procedures. See
page 26
10510 071000
TROUBLESHOOTING (cont.)
PROBLEM
Dilution (Iced Tea) cycle will not
start (cont.)
Inconsistent beverage level in dispenser (Hot Coffee)
PROBABLE CAUSE
2. Start Switch
3. Brew Timer (Iced Tea)
4. Brew Solenoid Valve (Iced Tea)
5. Dilution Solenoid Valve
1. Internal Flow Control (.195 GPM)
REMEDY
Refer to
Service
- Start Switch for
testing procedures. See page 27
Refer to
Service-
Brew Timer (Iced
Tea) for testing procedures. See
page 20 or 21
Refer to Service -
Brew Solenoid
Valve (Iced Tea) for testing procedures. See page 16
Refer to
Service
- Dilution Solenoid
Valve for testing procedures. See
page 24
(A) Direction of flow arrow must be
pointing towards the brewer.
(B) Remove the flow control and
check for obstruction. Clear or replace.
Consistently high or low beverage
level in the dispenser
2. Syphon System
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.
4. Water Pressure
1. Brew Timer
The brewer must be level or slightly
lower in front to syphon properly.
Inspect the tank assembly for excessive lime deposits. Delime as
required.
The water pressure to the brewer
must be at least 20 psi (128 kPa).
With the TEA/OFF/COFFEE switch in
the "TEA" position adjust the needle
valve to achieve the recommended
76 oz of concentrate then the timer
to achieve a total of 396 oz for each
three-gallon brew cycle.
Page 10
10510 071000
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