background image

Page 7

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 will not start (ST, STF,
STA & STFA)

PROBABLE CAUSE

1. No water

2. No power or incorrect voltage to
the brewer

REMEDY

Water lines and valves to the brewer
must be open.

(A1) Check the terminal block for
120  volts  across  the  black  and
white  terminals  on  two  wire  120
volt brewers.
(A2) Check the terminal block for
120 volts across the red and white
terminals and the black and white
terminal  on  three  wire  120/240
volt brewers.
(A3) Check the terminal block for
200 volts on Model STFB brewers
or 240 volts on "A Series" brewers
across  the  red  and  black  termi-
nals.
(A4) Check the terminal block for
100 volts on Model SDB brewers
across the white and black termi-
nals.

(B) Check circuit breakers or fuses.

29251 101598

Summary of Contents for S

Page 1: ...CE MANUAL BUNN O MATIC CORPORATION POST OFFICE BOX 3227 SPRINGFIELD ILLINOIS 62708 3227 PHONE 217 529 6601 FAX 217 529 6644 www bunnomatic com 29251 0000G 04 01 1998 Bunn O Matic Corporation S SA ST STA STF STFA BUNN ...

Page 2: ... 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 Offi...

Page 3: ...Page 3 00656 0000 USER NOTICES Continued 00882 0000 02763 0000 02765 0000 02769 0000 29251 101598 ...

Page 4: ...follows 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 Before electrically connecting the brewer remove the front and rear panel and rotate the thermostat knob fully counterclockwise to the O...

Page 5: ...funnel stops turn the thermostat knob to the ON position and wait approximately twenty minutes for the water in the tank to heat to the proper temperature Some water will drip from the funnel during this time this is due to expansion and should not occur thereafter 6 Empty the dispenser and initiate another brew cycle as directed 6A Models S SA Pour one pitcher of tap water into the screened area ...

Page 6: ... of grounds by gently shaking 3 Slide the funnel into the funnel rails 4 Place an empty dispenser beneath the funnel 5 Operate the brewer as directed 5A Models S SA Pour one pitcher of tap water into the screened area on top of the brewer 5B Models ST STF STA STFA Place the ON OFF switch in the ON upper position Momentarily press and release the start switch 6 When brewing is completed simply disc...

Page 7: ...lumbingfittingsaretightenedorloosened Thiswillhelp 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 F...

Page 8: ...rvice Start Switch for testing procedures See page 19 RefertoService Timerfortesting procedures See page 22 or 24 Refer to Service Solenoid Valve for testing procedures See page 18 A Direction of flow arrow must be pointing towards brewer B Remove the strainer flow con trol and check for obstructions Clear or replace Refer to Service Limit Thermo stat for testing procedures See page 16 Refer to Se...

Page 9: ...al water condi tions Excessive mineral build up onstainlesssteelsurfacescanini tiate corrosive reactions resulting in serious leaks 2 Control thermostat REMEDY Thebrewermustbelevelorslightly lower in front to syphon properly Inspect the tank assembly for ex cessive lime deposits Delime as required The water pressure to the brewer must be at least 20 psi 138 kPa A Early models Timer dial must indic...

Page 10: ...FA 1 Dispenser 2 Timer ST STF STA STFA REMEDY Thebrewermustbelevelorslightly lower in front to syphon properly Inspect the tank assembly for ex cessive lime deposits Delime as required Remove the solenoid valve and clear any obstructions Rebuild or replace the valve if necessary See page 18 RefertoService Timerfortesting procedures See page 22 or 24 Refer to Service Start Switch for testing proced...

Page 11: ... must be used for proper extraction A six hole stainless steel spray head must be used for proper extraction The BUNN paper filter must be centered in the funnel and the bed of ground leveled by gentle shak ing Placeanemptyfunnelonanempty dispenser beneath the sprayhead Initiate a brew cycle and check the water temperature immediately below the sprayhead with a ther mometer The reading should not ...

Page 12: ...nstall a regulator if necessary to lower the working pressure to ap proximately 50 psi 345 kPa Remove and clean lime off the tank heater See page 20 Check plumbing A Direction of arrow must be pointing towards brewer B Remove the strainer flow con trol and check for obstructions Clean or replace Refer to Service Solenoid Valve for testing procedures See page 18 RefertoService Liquidlevelcon trol b...

Page 13: ...wer from the power source before the removal of any panel or the replace ment of any component All components are accessible by the removal of thetopcoverortopwarmerhousingandfrontandrear inspection panels The top cover for Models with no top warmer and the top warmer housing is attached with four 8 32 screws Unplug upper wiring harness and set housing aside The front and rear inspection panels ar...

Page 14: ... 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 the brewer wiring harness 5 Locate the black wire on the control thermostat 6 Gently remove the capillary bulb and grommet from the tank 7 Check the voltage across the black wire of the control thermostat and the white insert on the two pole 100 or 120 vol...

Page 15: ...the grommet to the line 4 5 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 6 Carefully bend the capillary tube so that the tube and bulb inside the tank are in the vertical posi tion NOTE The capillary tube must be clear of any electri cal terminat...

Page 16: ...ed the limit thermo stat is operating properly If continuity is not present as described replace the limit thermostat P1800 P1586 FIG 4 LIMIT THERMOSTAT FIG 5 LIMIT THERMOSTAT TERMINALS Removal and Replacement 1 Remove all wires from limit thermostat termi nals 2 Carefully slide the limit thermostat out from undertheretainingclipandremovelimitthermo stat 3 Carefully slide the new limit thermostat ...

Page 17: ... the lower terminal the white red wire for the lower warmer switch the brown black wire for the top frontwarmerswitchortheblue blackwireforthe top rear switch 6 Check for continuity across the center and lower terminal with the switch in the ON position Continuity must not be present when the switch is in the OFF position If continuity is present as described reconnect the black wire to the center...

Page 18: ... Connect the brewer to the power source With ON OFF switch in the ON upper position press start switch and listen carefully in the vicinity of the solenoid valve for a clicking sound as the coil magnet attracts 7 Disconnect the brewer 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 water line before the sole...

Page 19: ...erminals in the upper position If continuity is present as described reconnect the WHI YEL wire to the top terminal and the WHI ORA wire to the bottom terminal If continuity is not present as described replace the switch P1591 P1589 FIG 10 START SWITCH WHI YEL to Brew Timer TL3 WHI ORAto Brew Timer TL5 Removal and Replacement 1 Remove the WHI YEL and WHI ORA wires from the start switch 2 Compress ...

Page 20: ...iusly described 2 Disconnect the water supply tube from the sole noid 3 On brewers with faucet disconnect the faucet 4 Remove sprayhead and the hex nut securing the sprayhead tube to the hood Set aside for reas sembly 5 Disconnect the wire from the tank level probe 6 Remove the thermostat capillary bulb as de scribed in section for control thermostat 7 Disconnect the wires from the limit thermosta...

Page 21: ...ring the tank heater to the bottom of tank Remove tank heater with gaskets and discard 16 Install new tank heater with gaskets to the tank and secure with two hex nuts 17 Installtankwithlimitthermostat sprayheadtube and tank heater 18 Reconnect the inlet and outlet water lines to the solenoid and faucet 19 Secure spayhead tube to hood using a hex nut 20 Install sprayhead P1593 FIG 13 TANK HEATER T...

Page 22: ...hite yellow wire from terminal TL5 Checkforcontinuityacrossthetwowireswhenthe start switch is pressed to the START position If continuity is present as described reconnect the wires and proceed to 6 If continuity is not present as described refer to the Wiring Diagrams and check the brewer wiring har ness 6 With a voltmeter check the voltage across termi nals TL1 and TL4 when the ON OFF switch is ...

Page 23: ...t timer kit on the back side of the front access panel 6 Adjust the timer as required Refer to Late Model Timer section on the following pages MINUTES BUNN O M ATIC P N 2620 120 VAC P1595 FIG 15 BREW TIMER TERMINALS WHI RED TL1 to ON OFF Switch WHI TL2 to Terminal Block and Warmer Element 120V Two Pole 120 208V or 120 240V Three Pole Terminal Block RED TL2 to Terminal Block and Warmer Element 200V...

Page 24: ...ibed proceed to 5 If voltage is not as described disconnect the brewer from the power source and replace the timer 5 With a voltmeter check the voltage across termi nals TL1 and TL4 when the ON OFF switch is in the ON position Connectthebrewertothepower source and press the start switch The indication must be a 120 volts ac for two wire 120 volt models three wire 120 208 volt models and three wire...

Page 25: ...chieved 2 Setting brew volumes To set a brew volume first checkthattheSET LOCKswitchisinthe SET position on the circuit board Place the ON OFF switch in the ON position press and hold the START switch until three distinct clicks are heard and then release the switch Failure to release the switch within two sec onds after the third click causes the volume setting to be aborted and previous volume s...

Page 26: ... must again be a 120 volts ac for three wire 120 208 volt models and three wire 120 240 volt models after a delay of approximately 5 seconds b 200 to 240 volts ac for two wire 200 or 240volt models after a delay of approximately 5 seonds 10 Disconnect the brewer from the power source and remove the jumper wire from terminal 4 Location The liquid level probe is located within the tank lid inside th...

Page 27: ...models after a delay of approximately 5 seconds b 200 to 240 volts ac for two wire 200 or 240 volt models after a delay of approximately 5 seconds 15 Move the probe s flat end to the brewer housing The indication must be 0 16 Move the probe s flat end away from the brewer housing The indication should again be a 120 volts ac for three wire 120 208 volt models and three wire 120 240 volt models b 2...

Page 28: ...elay relayisoperating properly If continuity is not present as described replace the relay Removal and Replacement 1 Remove all wires from the relay terminals 2 Removethetwo 6 32screwssecuringtherelay and shield to the mounting bracket 3 With the two 6 32 screws secure the new relay and shield to the mounting bracket 4 Refer to FIG 21 when reconnecting the relay wires 5 Fold the flap of the protec...

Page 29: ...mbly from the brewer 3 Disconnect the two wires from the warmer ele ment terminals 4 Removethetwo 8 32nutssecuringthewarmer element to the warmer plate 5 Securely install new warmer element 6 Reconnect the two wires to warmer element terminals 7 Securelyinstallwarmerassemblyonthebrewer 8 Refer to FIG 23 when reconnecting the wires P1601 P1602 FIG 22 WARMER ELEMENTS FIG 23 WARMER ELEMENT TERMINALS ...

Page 30: ...ng an ohmmeter If continuity is present the thermal cutoff is operating properly If continuity is not present as described replace the thermal fuse Removal and Replacement 1 Disconnect the thermal cutoff from the tank heater terminal and the limit thermostat or wir ing harness 2 Remove thermal cutoff and discard 3 Connect new thermal cutoff to the tank heater terminal and the limit thermostat or w...

Page 31: ...Page 31 29251 052500 ...

Page 32: ...Page 32 29251 052500 ...

Page 33: ...Page 33 29251 052500 ...

Page 34: ...Page 34 29251 052500 ...

Page 35: ...Page 35 29251 052500 ...

Page 36: ...Page 36 29251 052500 ...

Page 37: ...Page 37 29251 052500 ...

Page 38: ...Page 38 29251 052500 ...

Page 39: ...Page 39 29251 052500 ...

Page 40: ...Page 40 29251 052500 ...

Page 41: ...Page 41 29251 052500 ...

Page 42: ...Page 42 29251 080400 ...

Page 43: ...Page 43 29251 052500 ...

Page 44: ......

Reviews: