Service Manual - Guertech Inc.
Contents
1. 14 Limit ThermmoStal ios reete repetens 16 ette cotes 17 Solenoid cosa es 18 Start Switch Brew siesta 19 Tank Healer eana aa 20 Brew Timer Early Models 22 Digital Timer Late Models 24 Liquid Level 5 26 a nesa ea EE 28 Warmer 29 Thermal Cut off sie ette 30 Wiring 31 thru 43 FIG 1 COMPONENT ACCESS Page 13 29251 052500 SERVICE cont CONTROL THERMOSTAT FIG 2 CONTROL THERMOSTAT Location Models 5 amp SA The control thermostat is mounted on a bracket inside the rear inspection cover on the left side Models ST STA STF amp STFA The control ther mostat is located inside the front inspection cover on the component mounting bracket Page 14 Test Procedures 1 Disconnect the brewer from the power source 2 Locate the blue wire on the control thermostat 3 Check the voltage across the blue wire on the control thermostat and the white insert on two pole 100 or 120 volt terminal block or three pole 120 240 volt terminal blocks and the red insert on two wire 200 volt or 240 volt terminal block with a voltm2. FIG 11 START SWITCH TERMINALS 29251 052500 SERVICE cont TANK HEATER 12 TANK HEATER Location The tank heater is located inside the tank and secured to the tank bottom Test Procedures 1 Disconnect the brewer from the power supply 2 Check the voltage across the black and white wires on 100 or 120 volt models or the black and red wires for 120 240 volt models 200 volt models and 240 volt models with a voltmeter Connect the brew to the power source The indication must be a 120 volts ac for two wire 120 volt 15 and 20 amp models b 240 volts ac for three wire 120 240 volt models Page 20 C 200 to 240 volts ac for two wire 200 or 240 volt models d 100 volts ac for two wire 100 volt models 3 Disconnect the brewer from the power source If voltage is present as described proceed to 4 If voltage is not present as described refer to the Wiring Diagrams and check wiring harness 4 Disconnect the black wire and the white wire or red wire from the tank heater terminals 5 Check forcontinuity across the tank heater termi nals If continuity is present as described reconnect the wires the tank heater is operating properly If continuity is not present as described replace the tank heater NOTE If the tank heater remains unable to heat remove and inspect heater for cracks in the sheath Removal and Replacement 1 Remove top cover or top warmer housing as prevoiusly
3. gt SSA BUNN STF STFA OPERATING amp SERVICE MANUAL BUNN O MATIC CORPORATION POST OFFICE BOX 3227 SPRINGFIELD ILLINOIS 62708 3227 PHONE 217 529 6601 217 529 6644 29251 0000G 04 01 1998 0 Corporation www bunnomatic com WARRANTY Bunn O Matic Corp Bunn warrants the equipment manufactured by itto 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 three years from the date of installation 2 Bunn warrants the compressor on refrigeration equipment 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
4. 2 Disconnect the thermal cutoff from the tank heater terminal and the limit thermostat or wir ing harness 3 Check for continuity across the thermal cutoff terminals using 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 wiring har ness 4 Refer to FIG 24 when reconnecting wires Page 30 Thermal cutoff to BLK Lead Thermal cutoff to WHI or RED Lead IG 24 THERMAL CUT OF 29251 052500 SCHEMATIC WIRING DIAGRAM 5 GREEN L1 N SW amp THERMOSTAT LIMIT TW amp THERMOSTAT Suc MONS BLK oiie e BLK WHI MEA RI Ma Mapa AGUA ola RM dal oy WHI WHI KEEP WARM HEATER WHI BLK 1 BLU BLK P1 BLU BLK e WHI EUN WARMER WHI P3 P1 P2 amp P3 ARE PINS OF BLK 4 BRN BLK v A POLARIZED THREE PIN urn TOP FRONT CONNECTOR mem WARMER WHI BLK n WHI VIO i 7 LOWER WARMER 120 VOLTS AC 2 WIRE SINGLE PHASE 60 HZ Page 31 29251 052500 SCHEMATIC WIRING DIAGRAM 5 GREEN INDICATOR x o D SW amp THERMOST
5. ing Place an empty funnel onan empty dispenser beneath the sprayhead Initiate a Drew cycle and check the water temperature immediately below the sprayhead with a ther mometer The reading should not be less than 1959 Adjust the control thermostat to increase the watertemperature Replace if nec essary The BUNN paper filter must be centered in the funnel and the bed of grounds leveled by gently shak ing The nut on the solenoid must be tight or it will vibrate during op eration Plumbing lines should not resting on the counter top 29251 052500 TROUBLESHOOTING cont PROBLEM Brewer is making unusal noises ST STF STA amp STFA cont Automatic refill will not operate Beverage not staying hot in dis penser PROBABLE CAUSE 3 Water supply 4 Tank heater 1 No water 2 Strainer flow control 3 Solenoid valve 4 Liquid level control board or level probe 5 Relay 1 ON OFF switch 2 Warmer elements Page 12 REMEDY A The brewer must be connected to a cold water line B Water pressure to the brewer must not exceed 90 psi 620 kPa Install 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
6. Solenoid Valve for testing procedures See page 18 Referto Service Liquid level con trol board or level probe for test ing procedures See page 26 Refer to Service Relay for test ing procedures See page 28 Refer to Service ON OFF switch for testing procedures See page 17 Refer to Service Warmer ele ments fortesting procedures See page 29 29251 052500 SERVICE This section provides procedures for testing and replacing various major components used in this brewer should service become necessary Refer to Troubleshooting for assistance in determining the cause of any problem WARNING Inspection testing and repair of electrical equipment should be performed only by qualified service personnel The brewer should be unplugged when servicing except when electrical tests are re quired and the test procedure specifically states to plug in the brewer COMPONENT ACCESS WARNING Disconnect the brewer 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 the top cover or top warmer housing and front and rear inspection panels The top cover for Models with no top warmer and the top warmer housing is attached with four 78 32 screws Unplug upper wiring harness and set housing aside The front and rear inspection panels are attached with four 28 32 screws each Contents Control
7. discon nect the brewer from the power source and replace the timer If voltage is correct readjust the timer as required 29251 082100 SERVICE cont BREW TIMER Early Models cont Removal and Replacement 1 2 Remove all wires from the timer Remove the circuit board and dial plate from the brackets Install new timer circuit board as described in Late Model Timersection on the following pages Refer to Fig 17 when reconnecting the wires Install the Timer Setting decal provided with the replacement timer kit on the back side of the front access panel Adjust the timer as required Refer to Late Model Timer section on the following pages Page 23 E 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 or 240V Two Pole Termi nal Block WHI ORA TL3 to Start Switch top WHI GRN TL4 to Solenoid Valve or Relay Terminal B WHI YEL TL5 to Start Switch bottom OLD STYLE P1595 29251 082100 SERVICE cont DIGITAL BREW TIMER Late Models 16 DIGITAL BREW TIMER Location The timer is located inside the front inspection panel Some earlier models with the new timer will have them located inside the rear panel Test Procedures NOTE Do not remove or install wires whiletimer bo
8. 3 CONTROL THERMOSTAT TERMINALS 29251 052500 SERVICE cont LIMIT THERMOSTAT FIG 4 LIMIT THERMOSTAT Location The limit thermostat is located on the rear of tank assembly Test Procedures 1 Disconnect the brewer from the power source 2 Disconnect the blue and black wires from the limit thermostat 3 Check for continuity across the limit thermostat terminals with a ohmmeter If continuity is present as described the limit thermo stat is operating properly If continuity is not present as described replace the limit thermostat Page 16 Removal and Replacement 1 Remove all wires from limit thermostat termi nals 2 Carefully slide the limit thermostat out from underthe retaining clip and remove limitthermo stat 3 Carefully slide the new limit thermostat into the retaining clip 4 Refer to 5 when reconnecting the wires BLK to Tank Heater Switch BLK to BLU Lead from Control Thermostat 5 LIMIT THERMOSTAT TERMINALS 29251 052500 SERVICE cont ON OFF SWITCH Models ST STA STF amp STFA FIG 6 ON OFF SWITCH Location The ON OFF switch is located second from right on the switch panel Test Procedure 1 Disconnect the brewer from the power source 2 Viewing the switch from the back remove the white or red wire from the upper terminal and the black wire from the center terminal 3 Check the voltage across the white or red wire and th
9. position on the circuit board To increase a brew volume place the ON OFF switch in the position press and hold the START 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 brew volume place the ON OFF switch in the ON position press and release the START switch once for every two second interval to be removed from the total brew time period then imme diately press and hold down the START 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 brew volumes To seta brew volume first check thatthe SET LOCK switch is in the 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
10. tank initiate a second and a third brew cycle During the third brew cycle the tank will fill to its capacity and the excess will flow from the sprayhead out of the funnel and into the dispenser 4C Models STF amp STFA Brewers will fill automatically when lower ON OFF switch is placed in the ON position and tank will fill to capacity 5 When the flow of water from the funnel stops turn the thermostat knob to the 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 amp SA Pour one pitcher of tap water into the screened area on top of the brewer 6B Models ST STF STA amp STFA Place the ON OFF switch in the ON upper position and momentarily press and release the start switch 7 Place the ON OFF switch in the lower OFF position after water has stopped flowing from the funnel and let the water in the tank reheat to the proper temperature 8 Empty the dispenser and proceed as directed 8A Models S amp SA The brewer is now ready for use in accordance with the coffee brewing instructions on the next page 8B Models ST STF STA amp STFA Place the ON OFF switch in the ON upper position and momentarily press and release the start switch Check the water volum
11. 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 Page 25 NOTE Several ounces of water will continue to syphon from the tank after turning the switch OFF 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 volumes will decrease due to absorption by the coffee grounds 3 Setting programming disable feature If it be comes necessary to prevent anyone from changing brew time once programmed you can set the SET LOCK switch to the LOCK position This will prevent any further programming NOTE Torelocate a rear mounted digital brew timerto the front of the brewer order kit number 32005 0000 for 120 240V 3 wire models Order 32005 0001 for 200V 240V 2 wire models These kits have the parts necessary to relocate the timer e WHI RED to ON OFF Switch WHI to Terminal Block and Warmer element 120V two pole 120 208V or120 240V three pole terminal block or RED to Terminal Block and Warmer element 200V or 240V two pole ter minal block WHI ORN to Start Switch Top WHI GRN to Solenoid Val
12. 200 to 240 volts ac for two wire 200 or 240 volt models 4 Disconnect the brewer from the power source Page 22 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 har ness 5 Disconnect the white orange wire from terminal TL3 and the white yellow wire from terminal TL5 Check for continuity across the two wires when the start switch is pressed to the START position If continuity is present as described reconnect the wires and proceed to 76 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 in the ON position Connect the brewer to the power source The indication must be zero If voltage indications are other than described discon nect the brewer from the power source and replace the timer If voltage is correct proceed to 7 7 With a voltmeter check the voltage across termi nals TL1 and TL4 when the ON OFF switch is in the ON position Connect brewer to the power 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 120 240 volt models 200 to 240 volts ac for two wire 200 or 240 volt models If voltage indications are other than described
13. 500 SERVICE cont TIMER RELAY Models STF amp STFA Location The relay is located inside the front inspection panel on the bottom of component mounting bracket 20 TIMER RELAY Test Procedure 1 Disconnect the brewer from the power source 2 Remove the WHI RED wire from the terminal andthe WHI GRN wire from the B terminal on the relay 3 Check for continuity across the and termi nals If continuity is present as described reconnect the WHI RED and WHI GRN wires to the relay and pro ceed to 4 If continuity is not present as described replace the relay 4 Remove the WHI RED wire from terminal 5 and the WHI BLU wire from terminal 7 on the relay 5 Check for continuity across terminals 5 and 7 by manually closing the relay contact Continuity must be present until contact is released Page 28 If continuity is present as described reconnect the WHI RED and WHI BLU wires to the relay relay is operating properly If continuity is not present as described replace the relay 6 Remove the BLU wire from terminal 2 and the WHI BLU wire from terminal 7 on the relay 7 Check for continuity across terminals 2 and 7 by manually closing the relay contact Continuity must be present when contact is released If continuity is present as described reconnect the BLU and WHI BLU wires to the relay relay is operating properly If continuity is not present as described replace the rel
14. ARE PINS OF A BLK 47 Qr BRN BLK BRN BLK POLARIZED THREE PIN pide FRONT CONNECTOR WARMER RED BLK A RED LOWER WARMER 230 VOLTS AC 2 WIRE SINGLE PHASE Page 34 29251 052500 SCHEMATIC WIRING DIAGRAM SDB 100 VOLTSA C 2 WIRE SINGLE PHASE Page 35 29251 052500 SCHEMATIC WIRING DIAGRAM ST GREEN L1 SW amp N L LIMIT THERMOSTAT RMOSTA WHI ST15 amp 20 BLU oe 5 Se LT usc ST15 Q 120V ST20 120V 5735 240V WHI KEEP WARM HEATER seas WHI BLUIBLK P BLU BLK Li I P2 REAR WHI WHI SW2 WARMER I P3 P1 P2 amp P3 ARE PINS OF e PBNA D A POLARIZED THREE PIN xx TOP FRONT CONNECTOR WARMER I pou meet LOWER WARMER WHI RED BREW WHUORA TIMER 5 WHI GRN 7 __WHI YEL I 120 VOLTS AC 2 WIRE 120 240 VOLTS AC WIRE SINGLE PHASE Page 36 29251 052500 BLK WHI BLK BLK BLK SCHEMATIC WIRING DIAGRAM STA GRN YEL SUE THERMAL THERMAL LIMIT THERMOSTAT THERM FUSE THERMOSTAT i je en Uis ee oL RED WHI KEEP WARM HEATER RED BLU BLK __ RED WARMER RED P1 P2 8 ARE PINS OF E 5 BRN BLK BRWBLK i A POLARIZED THREE
15. AT LIMIT 34 8 THERMOSTA m BLK p RU RED nuh seeds uan dence id dea AAA eS oreet PPP TANK HEATER WHI WHI KEEP WARM HEATER 14 WHI 1 BLU BLK P1 BLU BLK encore TOP REAR WHI WHI Me WARMER WHI P3 P1 P2 amp P3 ARE PINS OF BIK ge PRWELK 1 1 A POLARIZED THREE PIN ecd TOP FRONT CONNECTOR WARMER BLK H WHI VIO 8 7 LOWER WARMER 120 240 VOLTS AC 3 WIRE SINGLE PHASE 60 HZ Page 32 29251 052500 L1 BLK WHI BLK BLK SCHEMATIC WIRING DIAGRAM SA GRN YEL SW amp L2 nA THERMOSTAT LIMIT THERMAL THERMAL i THERMOSTAT FUSE FUSE BU 4 BLK RED 6 0 0 ese TANK HEATER WHI KEEP WARM HEATER PM RED e Qu BLUBLK P BLU BLK _ TOP REAR RED 2 RED WARMER PNE RED e Bd P1 P2 amp P3 ARE PINS OF A BRN BLK BRN BLK POLARIZED THREE PIN TOP FRONT CONNECTOR SW3 WARMER I e do BED LOWER WARMER 240 VOLTS AC 2 WIRE SINGLE PHASE Page 33 29251 052500 SCHEMATIC WIRING DIAGRAM SA CE GRN YEL L1 SW amp 12 __ 5 ___ LIMIT THERMAL THERMAL i THERMOSTAT FUSE FUSE BLK e o e BLU de 7 1 1 RED TANK HEATER KEEP WARM HEATER INDICATOR RED BLK 2 Qu BLUBLK die TOP REAR RD R RED WARMER owe RED P1 P2 amp P3
16. HI RED 5 BOARD 2h BLU ico WHUBLU so pt REM 2 PROBE 120 VOLTS AC 2 WIRE 120 240 VOLTS 3 WIRE SINGLE PHASE Page 39 29251 052500 SCHEMATIC WIRING DIAGRAM STFA GRN YEL L1 SW amp L2 LIMIT THERMOSTAT res EE THERMOSTAT puede BLK p sul BLK RED TANK HEATER WHI KEEP WARM HEATER RED BLU BLK P BLU BLK P2 RED WARMER P1 P2 amp P3 ARE PINS OF 1 POLARIZED THREE PIN TOP FRONT CONNECTOR WARMER BRN BLK BRN BLK tee i BREW TIMER 4 40 E i LEVEL WARED L WHURED 5 BOARD 20 BLU yz HHL RED PROBE 230 VOLTS AC 2 WIRE SINGLE PHASE Page 40 29251 052500 SCHEMATIC WIRING DIAGRAM STFA NTW GRN YEL L1 SW amp L2 LIMIT THERMOSTAT s USE THERMOSTAT BLK j BU de ee j BLK RED i NM TANK HEATER WHI WHI KEEP WARM HEATER RED LOWER WARMER WHURED A iL 1 0 1 RED ___ _ __ BREW 4 p WHI ORA TIMER 3 WHI GRN WHI YEL ipu 4 LEVEL 2n WHURED WHU RED K5 wem BED jBOARD 2 BLU 7 230 VOLTS AC 2 WIRE SINGLE PHASE Page 41 29251 052500 SCHEMATIC WIRING DIAGRAM STFD35B READY INDICATOR i MEN BLU jd pn Sx du LIMIT Sw amp THERMOSTAT 7 THERMOSTAT wie e e 2 RED AM RR TANK HEATE
17. ONTROL THERMOSTAT cont Removal and Replacement 1 2 Remove wires from control thermostat leads Remove the thermostat capillary bulb by firmly pulling up on the capillary at the tank lid This will disengage the grommet from the tank lid Models 5 amp SA Remove the two 78 32 screws securing control thermostat bracket mounted inside the rear inspection panel Models ST STA STF amp STFA Remove the one 8 32 screw securing the control thermostat to the component bracket in the front inspection panel Slide the grommet to the line 4 5 above the bulb on the new capillary tube 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 Carefully bend the capillary tube so that the tube and bulb inside the tank are in the vertical posi tion Page 15 NOTE The capillary tube must be clear of any electri cal termination and not kinked 8 9 Models 5 4 SA Using two 78 32 screws secure the control thermostat inside the rear inspection panel Models ST STA STF amp STFA Using one 78 32 screw secure the control thermostat to the com ponent bracket inside the front inspection panel Refer to 3 when reconnecting the wires Adjust the control thermostat as required BLU to Limit Thermostat BLK to Tank Heater 227 2 9 M 9 9 e b e 9 U P2182 FIG
18. PIN Um TOP FRONT CONNECTOR SW3 WARMER WHI VIO RED pee ip WHURED BREW 2 P WHIORA TIMER WHVGRN 1 WHIYEL 220 240 VOLTS AC 2 WIRE SINGLE PHASE Page 37 29251 052500 SCHEMATIC WIRING DIAGRAM STB READYINDICATOR CREEN BLU BLK O L2 LIMIT SW amp THERMOSTAT TH ER MOST AT Ug BU Ne e RED m MER TANK HEATER SN i RED i BLU BLK Py BLU BLK a TOPREAR RED BLK 2 RED WARMER LN RED m P1 P2 amp P3 ARE PINS OF i BRN BLK BRN BLK q POLARIZED THREE PIN et TOP FRONT CONNECTOR Ret WARMER RED D D LOWER WARMER Tp WHU RED 2 WHIORA TIMER p WHI GRN p WHUYEL 200 VOLTS AC 2 WIRE SINGLE PHASE Page 38 29251 052500 SCHEMATIC WIRING DIAGRAM STF GREEN L1 SW amp l N 12 LIMIT 0 THERMOSTAT THE WHI STF15 amp 20 BLK BL E BLK masuanmssmasashnuanssmanusanssussusenhuassuusol i os KX E E TANK HEATER RED STF35 EE WHI WHI KEEP WARM HEATER S WHI BK eX BLUBLK BLU BLK 1 i P2 e e We WARMER P3 P1 P2 amp ARE PINS OF BLK Qj BRNBLK BRNBLK H A POLARIZED THREE PIN e e 1 SW3 WARMER WHI VIO BLK E I I eee LOWER WARMER Q WHI RED B WHI GRN WHI YEL ON EN Bb sr LEVEL 5 5 WHI RED 4 W
19. R s e V d BLU BLK TOP REAR RED P2 RED SW2 WARMER P3 P1 P2 amp P3 ARE PINS OF BRN BLK 1 A POLARIZED THREE PIN FRONT CONNECTOR SW3 WARMER 1 I LOWER WARMER are p WBI RED t BREW 2 5 WHIORA t TIMER WHI GRN S WHI YEL EA m iLIQUID LEVEL n WHI RED WULRED K 5 200 VOLTS AC uo TR 2 WIRE PROBE SINGLE PHASE Page 42 29251 080400 L1 SCHEMATIC WIRING DIAGRAM STF NTW GRN SW amp m L2 LIMIT THERMOSTAT THERMOSTAT pem BLK BLU WHI TANK HEATER WHI WHI KEEP WARM HEATER SL WHI WH BLK PS WHI VIO WHI LOWER B WHI WARMER L 1 jw oe WHURED m WHI BREW lt WHI ORA TIMER p WHI GRN WHI YEL 50 L 4i PNK 30 i LEVEL 24 WHI RED 4 WHI RED 5 BOARD 2 BLU p HELU So WHI K 2 PROBE 120 VOLTS AC 120 240 VOLTS AC 2 WIRE SINGLE PHASE Page 43 29251 052500
20. 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 lo
21. ard is installed Pressure applied to one side may cause damage to the board 1 Disconnectthe brewerfrom the power source and remove the front panel 2 With a voltmeter check the voltage across termi nals TL1 and TL2 when the ON OFF switch is in the ON position Connect the brewer to the power source The indication must be a 120 volts ac for two wire 120 volt models three wire 120 208 volt models and three wire 120 240 volt models b 200to 240 volts ac fortwo wire 200 or 240 volt models 3 Disconnect the brewer from the power source If voltage is present as described proceed to 74 If voltage is not present as described refer to the Wiring Diagrams and check the brewer wiring har ness Page 24 4 With a voltmeter check the voltage across termi nals TL1 and TL4 when the ON OFF switch is in the ON position Connect the brewer to the power source The indication must be zero volts If voltage is as described 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 Connectthe brewer to the power 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 120 240 volt models 200 to 240 volts ac for two wire 200 or 240 volt mod
22. ation Manual of the Food and Drug Administration FDA 02763 0000 CAUTION WARMERS AND SURFACES ARE HOT POUR IN WATER ONLY 02765 0000 CAUTION 02769 0000 CAUTION 3 29251 101598 ELECTRICAL REQUIREMENTS CAUTION The brewer must be disconnected from the power source until specified in nitial Set Up Model 15 has an attached cordset and requires 2 wire grounded service rated 120 volts ac 15 amp single phase 60 Hz NEUTRAL L1 BLACK P2185 Model 20 requires 2 wire grounded service rated 120 volts ac 20 amp single phase 60 Hz Proceed as follows Model 35 requires 3 wire grounded service rated 120 208 or 120 240 volts ac 20 amp single phase 60 Hz Proceed as follows L2 RED BLACK P2193 A amp B models re quire 2 wire grounded service rated 200 volts ac or 240 volts ac 20 amp single phase 50 Hz Pro ceed as follows 200 OR 240V NEUTRAL L1 BLACK P2185 SDB model requires 2 wire grounded service rated 100 volts ac 20 amp single phase 50 Hz Proceed as follows Electrical Hook Up CAUTION Improper electrical installation will damage electronic components 1 Anelectrician 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 elec
23. ay Removal and Replacement 1 Remove all wires from the relay terminals 2 Remove thetwo 6 32 screws securing the relay and shield to the mounting bracket 3 With the two 76 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 protective shield over the relay and tuck the edge inside the housing 2 BLU to L1 Liquid Level board 5 WHI RED to L2 on Liquid Level Board B WHI GRN toTL4 on Brew Timer 7 WHI BLU to Solenoid Valve A WHI RED to TL 1 on Brew Timer P1597 FIG 21 TIMER RELAY TERMINALS 29251 052500 SERVICE cont WARMER ELEMENTS Location The warmer elements are located under the warmer plates 22 WARMER ELEMENTS Test Procedures 1 Disconnect the brewer from the power source 2 Usethe WHI wire to the terminal block and the wire from the warmer element to the ON OFF switch BRN BLK Wire to Top Front Warmer Switch 3 Check voltage across the WHI wire from the terminal block and the wire from the switch to the warmer element with a voltmeter with the ON OFF switch in the ON position The indication must be a 120 volts ac for two wire 120 volt versions b 120 volts ac for three wire 120 208 volt versions or 120 240 volt versions 4 Disconnect the brewer from the power source If voltage is present as described proceed to 5 I
24. described 2 Disconnect the water supply tube from the sole noid 3 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 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 thermostat e 29251 052500 SERVICE cont TANK HEATER Cont 8 9 10 11 12 13 14 15 16 17 18 19 20 Disconnect the black wire and the white or red wire from the tank heater terminals Remove the three 78 32 nuts and holddown brackets securing the tank lid to the tank Remove the tank lid with level probe Remove the switch panel and disconnect the leads to the tank Keep Warm heater On 100 volt models equipped with rear drain open the shut off valve and drain water from the tank Disconnect drain tube and fittings from tank Direct the pink probe wire capillary tube and top warmer wiring harness through the nylon bush ing located on the rear of the basin flange Lift tank and fill basin assembly from housing and drain water from tank Remove the two hex nuts securing the tank heater to the bottom of tank Remove tank heater with gaskets and discard Install new tank heater with gaskets to the tank and secure with two hex nuts Install tank with limit thermostat sprayhead
25. e page 16 Refer to Service Control Ther mostatfortesting procedures See page 14 Refer to Service Tank Heater for testing procedures See page 20 A Direction of flow arrow must be pointing towards the brewer B Remove the strainer flow con trol and check for obstruction Clear or replace Refer to Service Liquid Level Board for testing procedures See page 26 29251 052500 TROUBLESHOOTING cont PROBLEM Inconsistent beverage level in dis penser cont Consistently low beverage level in the dispenser ST STF STA amp STFA Spitting or excessive steaming PROBABLE CAUSE 3 Syphon system 4 Lime build up CAUTION Tank and tank compo nents should be delimed regularly depending on local water condi tions Excessive mineral build up onstainless steel surfaces can ini tiate corrosive reactions resulting in serious leaks 5 Water pressure ST STF STA amp STFA 1 Timer 2 Strainer flow control 222 GPM 1 Lime build up CAUTION Tank and tank compo nents should be delimed regularly depending on local water condi tions Excessive mineral build up onstainless steel surfaces can ini tiate corrosive reactions resulting in serious leaks 2 Control thermostat Page 9 REMEDY The brewer must be level or slightly lower in front to syphon properly Inspect the tank assembly for ex cessive lime deposits Delime as required The water pressure to the brewer mus
26. e black wire with a voltmeter Connect the brewer to the power source The indication must be a 120 volts ac for two wire 120 volt models and three wire 120 240 volt models b 200 to 240 volts ac for two wire 200 or 240 volt models C 100 volts ac for two wire 100 volt models 4 Disconnect the brewer from the power source If voltage is present as described reconnectthe white or red wire and proceed to 5 If voltage is not present as described refer to the Wiring Diagrams and check the brewer wiring har ness Page 17 5 With the black wire removed remove from the lower terminal the white red wire for the lower warmer switch the brown black wire for the top front warmer switch orthe blue black wire for the 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 terminal and the white red to the lower terminal If continuity is not present as described replace the switch Removal and Replacement 1 Remove the wires from the switch terminals 2 Compress the clips inside the switch panel and gently push the switch through the opening 3 the new switch into the opening and spread the clips to hold switch in the switch panel 4 Refer to FIG 7 when reconnecting the wires BLK
27. e in the dispenser after water has stopped flowing from the funnel It should be 64 ounces 9 If not disconnect the brewer from the power source On early models remove the access panel Adjust the timer as required See service section Replace the panel connect the brewer to the power source and allow the water to reheat start and measure another brew cycle 10 Repeat step 9 until 64 oz water volume is achieved 11 The brewer is now ready for use in accordance with the coffee brewing instructions on the next page Page 5 29251 052500 OPERATING CONTROLS Models S amp SA These models function without operating controls Models ST STF STA amp STFA ON OFF SWITCH Placing the ON OFF switch in the OFF lower position stops brewing Stopping a brew cycle after it has been started will not stop the flow of water into the funnel until the tank syphons down to its proper level Placing the switch in the ON upper position supplies power to the brew station warmer and enables the brew circuit and on Models STF and STFA refills the tank START SWITCH Momentarily pressing and releasing the switch starts a brew cycle when ON OFF switch is inthe ON upper position NOTE The ON OFF switch must be in the ON upper position to initiate and complete a brew cycle COFFEE BREWING Insert a BUNNS filter into the funnel Pour the fresh coffee into the filter and level the bed of grounds by gently shaking Slide the funnel into
28. els If voltage is as described the brew timer is operating properly Reset the timer as required to obtain the desired brew volume If voltage is notas described testthe START switch for Operation before replacing the timer see page 19 Test ON OFF Switch if START Switch is functional see page 17 If voltage is as described for both switches disconnect the brewer from the power source and replace the timer Removal and Replacement NOTE Do not remove or install wires while timer board is installed Pressure applied to one side may cause damage to the board 1 Remove the two 6 32 screws securing circuit board to component mounting bracket 2 Remove circuit board and nylon spacers 3 Remove all wires from the timer 4 Attach all wires to the replacement timer board prior to installation to the component mounting bracket Refer to FIG 17 when reconnecting the wires 5 Install new circuit board with nylon spacers to component mounting bracket 6 Adjust the timer as described below 29251 011501 SERVICE cont DIGITAL BREW TIMER Late Models cont Timer Setting NOTE Check that the brewer is connected to water supply the tank is properly filled and a funnel and server are in place prior to setting or modifying volumes NOTE All volume settings must be done with the sprayhead installed 1 Modifying brew volumes To modify a brew vol ume first check that the SET LOCK switch is in the
29. eter Connect the brewer to the power source The indication must be a 120 volts ac for two wire 120 volt models and three wire 120 240 volt models b 200 to 240 volts ac for two wire 200 or 240 volt models C 100 volts ac for two wire 100 volt models 4 Disconnect the brewer from the power source If voltage is present as described proceed to 75 If voltage is not present as described referto 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 volt or three pole 120 240 volt terminal block and the red insert on the two pole 200 volt or 240 volt terminal block with a voltmeter when the control thermostat is turned ON Fully clockwise Connect the brewer to the power source The indication must be a 120 volts ac for two wire 120 volt models and three wire 120 240 volt models b 200to 240 volts ac for two wire 200 volt or 240 volt models C 100 volts ac for two wire 100 volt models 8 Disconnect the brewer from the power source If voltage is present as described reinstall the capillary tube into the tank to the line 4 5 above the bulb the control thermostat is operating properly If voltage is not present as described replace the thermostat 29251 052500 SERVICE cont C
30. f voltage is not present as described refer to wiring diagrams and check brewer wiring harness 5 Checkthe continuity across the two terminals on the warmer element If continuity is present as described reconnect the wires on the warmer element If continuity is not present as described replace the warmer element Removal and Replacement 1 Remove the three 24 40 screws securing the warmer assembly to the brewer 2 the warmer assembly from the brewer 3 Disconnect the two wires from the warmer ele ment terminals 4 Remove the two 8 32 nuts securing the warmer element to the warmer plate 5 Securely install new warmer element 6 Reconnect the two wires to warmer element terminals 7 Securely install warmer assembly on the brewer 8 Refer to FIG 23 when reconnecting the wires BLU BLK Wire to Top Rear Warmer Switch WHI Wire to Terminal Block White Insert on 120 208V or 120 240V Models or RED Wire to Terminal Block Red Insert on 200V or 240V Models WHI VIO Wire to Lower Warmer ON Switch WHI Wire to Terminal Block White Insert on 120 208V or 120 240V Models or RED Wire to Terminal Block Red Insert on 200V or 240V Models FIG 23 WARMER ELEMENT TERMINALS Page 29 29251 052500 SERVICE cont THERMAL CUT OFF Models SA STA amp STFA Location The thermal cutoffs are located on both tank heater terminals Test Procedures 1 Disconnect the brewer from the power source
31. he solenoid valve 9 Refer to FIG 9 when reconnecting the wires o noc WHI GRN to Brew Timer WHI BLU to Relay WHI to Main Harness Models STF amp STFA FIG 9 SOLENOID TERMINALS 29251 052500 SERVICE cont START SWITCH Models ST STA STF amp STFA FIG 10 START SWITCH Location The START switch is located far right on the switch panel Test Procedures 1 Disconnect the brewer from the power supply 2 BDisconnectthe WHI YEL wire from the top switch terminal and the WHI ORA wire from the bottom switch terminal 3 Check for continuity across the two terminals on the switch when it is held in the lower position Continuity must not be present across these terminals 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 Page 19 Removal and Replacement 1 Remove the WHI YEL and WHI ORA wires from the start switch 2 Compress the clips inside the hood and gently push the switch through the opening 3 Push new switch into the opening and spread the clips to hold the start switch in the hood 4 Refer to 11 when reconnecting the wires WHI YEL to Brew Timer TL3 ECT WHI ORAto Brew Timer TL5
32. is present as described reconnect the wires FIG 9 to the solenoid If continuity is not present as described replace the solenoid valve Page 18 6 Check the solenoid valve for coil action Connect the brewer to the power source With ON OFF switch in the ON upper position press start switch and listen carefully in the vicinity of the solenoid valve for 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 the water line before the solenoid valve 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 Remove the wires from the solenoid valve Turn off the water supply to the brewer Disconnect the water lines to and from the sole noid valve 4 Remove the two 28 32 screws securing the so lenoid mounting bracket to the component bracket Remove solenoid bracket and solenoid valve as an assembly 5 Remove the two 10 32 screws and lockwashers securing the solenoid valve to the solenoid bracket 6 Using two 10 32 screws and lockwashers in stall new solenoid valve on solenoid mounting bracket 7 Using two 8 32 screws install solenoid valve and bracket to the component bracket 8 Securely fasten the water lines to and from t
33. nect the brewer to the power source Turn the ON OFF switch to the ON position The indication must be a 120 volts ac for three wire 120 208 volt mod els 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 240 volt models after a delay of approximately 5 seconds 15 Movethe probe s flat end to the brewer housing The indication must be 0 16 Movethe 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 200 to 240 volts ac for two wire 200 or 240 volt models 17 Disconnect the brewer from the power source Page 27 If voltage is present as described reinstall the probe the level control board and level probe are operating properly If voltage is not present as described check the pink probe wire Removal and Replacement 1 Remove all wires from the level control board 2 Remove two 78 32 screws and lockwashers holding level control board to component bracket 3 Install the new level control board to the component bracket Make certain that the lockwashers are between the level control board and the component bracket 4 Refer to FIG 19 when reconnecting the wires BLU to Relay 2 WHI RED to Relay 5 and Timer TL1 WHI to Timer TL2 PNK to Probe FIG 19 LIQUID LEVEL CONTROL BOARD TERMINALS 29251 052
34. obstructions Rebuild or replace the valve if necessary See page 18 Refer to Service Timer for testing procedures See page 22 or 24 Refer to Service Start Switch for testing procedures See page 19 Refer to Service LiquidLevel Board for testing procedures See page 26 Refer to Service Relay for testing procedures See page 28 Remove the Solenoid Valve and clean any obstruction Rebuild or replace the valve if necessary See page 18 The dispenser must be completely empty before starting a brew cycle Referto Service Timer fortesting procedures See page 22 or 24 29251 052500 TROUBLESHOOTING cont PROBLEM Beverage overflows dispenser cont Weak beverage Dry coffee grounds remain in the funnel Brewer is making unusal noises ST STF STA amp STFA PROBABLE CAUSE 3 Solenoid valve ST STF STA amp STFA 1 Filter type 2 Coffee grind 3 Sprayhead 4 Funnel loading 5 Water temperature 1 Funnel loading 1 Solenoid valve 2 Plumbing lines Page 11 REMEDY Remove the Solenoid Valve and clean any obstruction Rebuild or replace the valve if necessary See page 18 The BUNN paper filter must be used for proper extraction fine or drip grind 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
35. p 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 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 29251 011800 Page 4 INITIAL SET UP CAUTION The brewer must be disconnected from the power source throughout the initial set up except when specified in the instructions 1 Insert an empty funnel into the funnel rails 2 Place an empty dispenser under the funnel 3 Remove the front or rear panel and turn the thermostat knob to the OFF position and connect the brewer to the power source 4 Fill the tank with water as directed 4A Models S amp SA Pour three pitchers of tap water into the screened area on top of the brewer Allow approximately two minutes between pitchers for water to flow into the tank While the third pitcher of water is entering the tank the tank will fill to capacity and the excess will flow from the sprayhead out of the funnel and into the dispenser 4B Models ST STA Connect the brewer to the power source place the ON OFF switch in the upper position and momentarily press and release the start switch Water will begin flowing into the tank When water stops flowing into the
36. r two wire 200 or The liquid level probe is located within the tank lid 240volt models after a delay of approximately 5 inside the fill basin The liquid level board is located seonds inside the rear inspection panel on the top left of 10 Disconnect the brewer from the power source component mounting bracket and remove the jumper wire from terminal 4 Test Procedure 1 Disconnect the brewer from the power source 2 Remove the blue wire from terminal 1 and the pink wire from terminal 4 of the circuit board 3 Check the voltage across terminals 2 and 3 with a voltmeter Connect the brewer to the power source Turn the ON OFF switch to the ON position The indication must be a 120 volts ac for two wire 120 volt models and three wire 120 240 volt models b 200 to 240 volts ac for two wire 200 volt or 240 volt models C 100 volts ac for two wire 100 volt models Page 26 29251 052500 SERVICE cont LIQUID LEVEL CONTROL BOARD Models STF amp STFA Cont If voltage is present as described the level control board is operating properly proceed to 711 If voltage is not presentas described replace the level control board 11 Reconnect the pink wire to terminal 4 12 Gently pull the probe out of the tank lid and inspect for corrosion Replace it if necessary 13 Place the probe so that neither end is in contact with any metal surface of the brewer 14 Check the voltage across terminals 1 amp 3 with a voltmeter Con
37. ss 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 00831 0000 USER NOTICES 00658 0000 AWARNING A WARNING Fill water tank before turning on thermostat or connecting appliance to power source DISCARD DECANTER Use only on a properly protected l EN Ke IF circuit capable of the rated load CRACKED Electrically ground the chassis ___ Follow national local electrical codes HEATED FUNNEL CONTENTS OR EXPOSED ELECTRIC ELEMENTS Do not use near combustibles FAILURE TO COMPLY RISKS EQUIPMENT DAMAGE ORSHOSISHAZARD READ THE ENTIRE OPERATING MANUAL BEFORE USING THIS PRODUCT FAILURE TO COMPLY RISKS INJURY PN 00658 0000F 6 98 1985 BUNN O MATIC CORPORATION Page 2 29251 042301 READ THE ENTIRE OPERATING MANUAL BEFORE BUYING OR USING THIS PRODUCT THIS APPLIANCE IS HEATED WHENEVER CONNECTED TO A POWER SOURCE 00831 0000F 3 98 1988 BUNN O MATIC CORPORATION USER NOTICES Continued 00656 0000 00882 0000 HOT WATER This equipment is to be installed to comply with the Basic Plumbing Code of the Building Officials and Code Do Not Use Administrators International Inc BOCA During Brew Cycle and the Food Service Sanit
38. t be at least 20 psi 138 kPa A Early models Timer dial must indicate at least two minutes and fifteen seconds B Referto Service Digital Timer for testing procedures See page 24 A Direction of flow arrow must be pointing towards brewer B Remove the strainer flow con trol and check for obstructions Clear or replace Inspect tank assembly for exces sive lime deposits Delime as re quired Refer to Service Control Ther mostatfortesting procedures See page 14 29251 052500 TROUBLESHOOTING cont PROBLEM Dripping from sprayhead Water flows into tank continuously ON OFF Switch ON Water flows into tank continuously ON OFF Switch OFF Beverage overflows dispenser PROBABLE CAUSE 1 Syphon system 2 Lime build up CAUTION Tank and tank compo nents should be delimed regularly depending on local water condi tions Excessive mineral build up stainless steel surfaces can ini tiate corrosive reactions resulting in serious leaks 3 Solenoid valve ST STF STA amp STFA 1 Timer ST STF STA amp STFA 2 Start switch 3 Liquid level board 4 Relay 1 Solenoid valve ST STF STA amp STFA 1 Dispenser 2 Timer ST STF STA amp STFA Page 10 REMEDY The brewer must be level or slightly 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
39. the funnel rails Place an empty dispenser beneath the funnel Operate the brewer as directed 5A Models S amp SA Pour one pitcher of tap water into the screened area on top of the brewer 5B Models ST STF STA amp STFA Place the ON OFF switch in the ON upper position Momentarily press and release the start switch 6 When brewing is completed simply discard the grounds and filter Qr op CE CLEANING 1 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 2 Check and clean the sprayhead The sprayhead holes must always remain open 3 With the sprayhead removed insert the deliming spring provided all the way into the sprayhead tube When inserted properly no more than two inches of spring should be visible Saw back and forth five or six times NOTE In hard water areas this may need to be done daily It will help prevent liming problems in the brewer and takes less than a minute Page 6 29251 101598 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 0 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
40. to Terminal Block Black WHI to Terminal Block Insert eeri White Insert 120 208V or 120 240V Models RED to Terminal Blck Red Insert on 200V or 240V Models WHI VIO to Lower Warmer BRN BLK to Top Front Warmer BLU BLK to Top Rear Warmer E T FIG 7 ON OFF SWITCH TERMINALS 29251 052500 SERVICE cont SOLENOID VALVE Models ST STA STF amp STFA FIG 8 SOLENOID Location The solenoid valve is located inside the front inspection panel on the center lower part of the com ponent mounting bracket Test Procedures 1 Disconnect the brewer from the power source 2 Disconnect the wires FIG 9 from the solenoid valve With the ON OFF switch in the ON upper position press the start switch 3 Check the voltage across the two wires with a voltmeter Connect the brewer to the power source The indication must be a 120 volts ac for two wire 120 volt models and three wire 120 240 volt models b 200 to 240 volts ac for two wire 200 or 240 volt models C 100 volts ac for two wire 100 volt models 4 Disconnect the brewer from the power source If voltage is present as described proceed to 5 If voltage is not present as described refer to Wiring Diagrams and check brewer wiring harness 5 Check for continuity across the solenoid valve coil terminals If continuity
41. trically connecting the brewer remove the front and rear panel and rotate the thermostat knob fully counterclockwise to the OFF position Keep this knob in the OFF position until performing the Initial Set Up 4 Feed the power cord through the strain relief and connect it to the terminal block 5 Connect the brewer to the power source and verify the voltage at the terminal block before proceeding Models 5 and ST 15 have cord attached Replace all panels 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 NOTE Schematic wiring diagrams are included in this manual PLUMBING REQUIREMENTS Models S amp SA These models are completely portable and require no attached plumbing Models ST STA STF amp STFA These brewers must be connected to a cold water system with operating pressure between 20 and 90 psi 138 and 620 kPa from a 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 flare NOTE Bunn O Matic recommends 1 4 copper tubing for installations of less than 25 feet and for more than 25 feet from the water supply line A tight coil of copper tubing in the water line will facilitate moving the brewer to clean the counterto
42. tube and tank heater Reconnect the inlet and outlet water lines to the solenoid and faucet Secure spayhead tube to hood using a hex nut Install sprayhead 21 22 23 24 20 Page 21 Reconnect the wires to the limit thermostat and control thermostat See limit thermostat and control thermostat sections in this manual when reconnecting wires Install tank lid with holddown brackets and 8 32 nuts Install the thermostat capillary bulb as described in section for control thermostat Reconnect the wire to the liquid level probe Refer to FIG 13 when reconnecting the tank heater wires WHI or RED Wire From Tank Heater E BLK Wire to Limit Thermostat 13 TANK HEATER TERMINALS 29251 052500 SERVICE cont BREW TIMER Early Models ST STA STF amp STFA FIG 14 BREW TIMER Location Thetimer dial is located inside the front inspection panel on the top of component mounting bracket The timer board is located inside the rear inspection panel on the component mounting bracket Test Procedures 1 Disconnect the brewer from the power source 2 Rotate the dial fully counterclockwise 3 With a voltmeter check the voltage across termi nals TL1 and TL2 when the ON OFF switch is in the ON position Connect the brewer to the power source The indication must be a 120 volts ac for two wire 120 volt models three wire 120 208 volt models and three wire 120 240 volt models
43. ve or Relay Terminal B TL5 WHI YEL to Start Switch Bottom FIG 17 DIGITAL TIMER WIRING 29251 011501 SERVICE cont LIQUID LEVEL CONTROL BOARD Models STF amp 4 Disconnect the brewer from the power source If voltage is present as described proceed to 75 If voltage is not present as described refer to the wiring diagrams and checkthe brewer wiring harness 5 Reconnect the blue wire to terminal 1 6 Carefully connect a piece of insulated jumper wire to terminal 4 Keep the other end of this wire away from any metal surface of the brewer 7 Checkthe voltage across terminals 1 amp 3 with a voltmeter Connect the brewer to the power source Turn the ON OFF switch to the ON position The indication must 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 240 volt models after a delay of approximately 5 seconds 8 Touch the free end of jumper wire to the brewer housing The indication must be 0 9 Move the jumper wire away from the brewer housing The indication must again be FIG 18 LIQUID LEVEL PROBE a 120 volts ac for three wire 120 208 volt amp CONTROL BOARD models and three wire 120 240 volt models after a delay of approximately 5 seconds Location b 200 to 240 volts ac fo
44. 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 e Follow recommended service procedures Replace all protective shields or safety notices PROBLEM PROBABLE CAUSE REMEDY Brew cycle will not start ST STF 1 No water Water lines and valvesto the brewer STA amp STFA must be open 2 power or incorrect voltage to A1 Check the terminal block for the brewer 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
45. 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 Page 7 29251 101598 TROUBLESHOOTING cont PROBLEM Brew cycle will not start cont ST STF STA amp STFA Water is not hot Inconsistent beverage level in dis penser PROBABLE CAUSE 3 ON OFF switch 4 Start switch 5 Timer 6 Solenoid valve 7 Strainer flow control 222 GPM 1 Limit thermostat CAUTION Do not eliminate or bypass limit thermostat Use only BOM replacement part 29329 1000 2 Control thermostat 3 Tank heater 1 Strainer flow control 222 GPM ST STF STA amp STFA 2 Liquid level board or level probe Page 8 REMEDY Refer to Service ON OFF Switch for testing See page 17 Refer to Service Start Switch for testing procedures See page 19 Referto Service Timer fortesting 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 Se
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