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Bunn C Series Service & Repair Manual

Summary of C Series

  • Page 1

    Service & repair manual bunn-o-matic corporation post office box 3227 springfield, illinois 62708-3227 phone: (217) 529-6601 fax: (217) 529-6644 41711.0001b 05/12 ©2009 bunn-o-matic corporation c, cs, ct, cwtf, crt, crtf series including dv, mv, aps/tc/ts, single cw & twins supercedes service manual...

  • Page 2

    Page 2 41711.1 030912 bunn-o-matic commercial product warranty bunn-o-matic corp. (“bunn”) warrants equipment manufactured by it as follows: 1) airpots, thermal carafes, decanters, gpr servers, iced tea/coffee dispensers, mcp/mca pod brewers thermal servers and thermofresh servers (mechanical and di...

  • Page 3

    Page 3 41711.1 052009 contents trouble shooting .............................................................................................................. 4 component access ........................................................................................................ 10 control thermo...

  • Page 4

    Page 4 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 ...

  • Page 5

    Page 5 troubleshooting (cont.) brew cycle will not start (cont.) water is not hot probable cause remedy 3. On/off switch 4. Start switch 5. Timer 6. Solenoid valve 7. Water strainer/flow control (.222 gpm) early models 1. Tank heater switch 2. (a) limit thermostat (b) thermal cut-off (brewers with f...

  • Page 6

    Page 6 troubleshooting (cont.) inconsistent beverage level in dispenser consistently low beverage level in the dispenser spitting or excessive steaming 1. Strainer /flow control (.222 gpm) early models. 2. Syphon system 3. Lime build-up caution - tank and tank components should be delimed regularly ...

  • Page 7

    Page 7 troubleshooting (cont.) spitting or excessive steaming (cont.) dripping from sprayhead water flows into tank continu- ously (on/off switch "on") water flows into tank continu- ously (on/off switch "off") beverage overflows dispenser 2. Control thermostat 1. Syphon system 2. Lime build-up caut...

  • Page 8

    Page 8 troubleshooting (cont.) weak beverage dry coffee grounds remain in the funnel brewer is making unusal noises 1. Filter type 2. Coffee grind 3. Sprayhead 4. Funnel loading 5. Water temperature 1. Funnel loading 1. Solenoid 2. Plumbing lines 3. Water supply problem probable cause bunn® paper fi...

  • Page 9

    Page 9 troubleshooting (cont.) brewer is making unusal noises (cont.) low beverage serving tempera- ture 4. Tank heater 1. Warmer 2. On/off switch remove and clean lime off the tank heater. Refer to service - warmer ele- ment for testing procedures. Refer to service - on/off switch for testing proce...

  • Page 10

    Page 10 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 electri- cal equipmen...

  • Page 11

    Page 11 service (cont.) optional electronic thermostat (ert): the ert is located inside the trunk on the upper left side of the component bracket. Test procedures: 1. Disconnect the brewer from the power source. 2. Gently remove the temperature sensor and grom- met from the tank. 3. Check voltage ac...

  • Page 12

    Page 12 location: the on/off switch(s) are located on the front of the hood. 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 acro...

  • Page 13

    Page 13 service (cont.) start switches location: crt/crtf on brewers w/out fresh light, the start switch is located in the right front of the hood. On brewers w/fresh light, the start switch is located on the right side of the hood. Location: ct/cwt/cwtf/twins on most "ct" series brewers, the start ...

  • Page 14

    Page 14 service (cont.) solenoid valves location: the solenoid valve is located inside the trunk on the lower center part of the component bracket. Test procedures: 1. Disconnect the brewer from the power source. 2. Disconnect the white and black wires from the solenoid valve. With the "on/off" swit...

  • Page 15

    Page 15 41711.1 052009 120vac - 1.18k 240vac - 3.76k 120vac - 247 240vac - 757 120vac - 334 service (cont.) solenoid valves disassembly: 1. Use of the basin wrench 01060.0000 is recom- mended for disassembly of early style valves as illustrated below. 2. Disconnect from power source and turn off the...

  • Page 16

    Page 16 service (cont.) tank heater location: the tank heater is located inside the tank and secured to the tank lid. Test procedures: 1. Disconnect the brewer from the power supply. 2. Check the voltage across the black and white wires on 120 volt models or the black and red wires for 120/240 volt ...

  • Page 17

    Page 17 1800w-120v 7.40 - 8.70 1850w-220v 24.40 -28.40 3500w-200v 10.70 -12.36 3500w-240v 15.36 -17.90 heater resistance if resistance is present as described, reconnect the wires, the tank heater is ok. If resistance is not present as described, replace the tank heater. Note - if any resistance is ...

  • Page 18

    Page 18 service (cont.) tank heater switch location: the tank heater switch is located on the rear of the brewer on the upper left side of the trunk. Test procedure: 1. Disconnect the brewer from the power source. 2. Disconnect the black wire from the limit thermo- stat. 3. With the tank heater swit...

  • Page 19

    Page 19 service (cont.) tank heater switch (cont.) fig. 19-1 tank heater switch terminals 15. Set tank assembly inside the hood on mounting brackets and secure with two #8-32 screws. 16. Reconnect the wires to the limit thermostat, tank heater and the control thermostat. Refer to limit thermostat, t...

  • Page 20

    Page 20 location: the thermal cut-off (tco) is a thermal fuse located above the tank lid, connected to the tank heater. Note: installed only on tanks with coil faucet. Ce models have an additional tco connected to the other heater terminal. Test procedures: 1. Disconnect the brewer from the power so...

  • Page 21

    Page 21 service (cont.) 41711.1 052009 coil/faucet location: the coil for the faucet is located in the tank. Operation: water inside the coil is separate from the brewing water and is always under line pressure. Brewing water in the tank heats the submerged coil. Use of a coil faucet during a brew c...

  • Page 22

    Page 22 service (cont.) 41711.1 052009 limit thermostat location: the limit thermostat is located inside the rear of the hood on the tank lid. 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 ac...

  • Page 23

    Page 23 recovery booster relay (optional) fig. 23-1 recovery booster relay location the recovery booster(s) are located inside the trunk on the center of the component brackets just above the solenoid valve. The coil is activated by the timer/ solenoid circuit. The contacts then close, bypassing the...

  • Page 24

    Page 24 service (cont.) timer (early models) location: the timer is located inside the front of the trunk on the upper right side of component bracket. Test procedure. 1. Disconnect the brewer from the power source. 2. Disconnect the polarized, three pin connector from the brewer wiring harness. 3. ...

  • Page 25

    Page 25 service (cont.) freshness timer (early models) location: the freshness timer is located inside the front of the trunk on the component bracket. Operation: the freshness timer activates an led on the control panel after a predetermined amount of time (after the brew cycle) to indicate carafe ...

  • Page 26

    Page 26 digital brew timer (late models) fig. 26-1 digital brew timer service (cont.) location: the timer is located inside the front of the trunk on the upper right side of component bracket. Test procedure note: do not remove or install wires while timer board is installed. Pressure applied to one...

  • Page 27

    Page 27 timer setting: note: prior to setting or modifying volumes, check that the brewer is connected to water supply, the tank is properly filled, and a funnel and server are in place. Note: all volume settings must be done with the sprayhead installed. 1. Modifying brew volumes. To modify a brew ...

  • Page 28

    Page 28 warmer element(s) location: the warmer element(s) is located under the warmer plate. Test procedures: 1. Disconnect the brewer from the power source. 2. With a voltmeter, check voltage across the two wires at the warmer element with the "on/off" switch in the "on" position. Connect the brewe...

  • Page 29: Schematic Wiring Diagram

    Page 29 l1 blk whi blk blk blk blk blk vio brn/blk yel whi/vio left front warmer left rear warmer right front warmer right rear warmer blk blk tank heater whi (model 20) n l2 red (model 35) green whi whi whi whi whi whi whi whi whi whi whi/grn whi/blu lower center warmer blu whi/red whi/red whi/red ...

  • Page 30: Schematic Wiring Diagram

    Page 30 l1 blk blk blk blk blk blk brn/blk yel vio whi/vio whi/red whi/red whi/red whi/blu red red red red red red red whi/grn brew timer t1 t5 t3 t4 t2 blu start switch whi blk blk grn/yel red l2 whi red red sol tank heater (model crtf5a only) thermal cut-off blu heater switch limit thermostat "kee...

  • Page 31: Schematic Wiring Diagram

    Page 31 l1 blk blk whi/red whi/red whi/red blk yel whi/vio brn/blk vio blk blk blk lower center warmer on/off switch on/off switch on/off switch on/off switch on/off switch blk blk green tank heater whi l2 whi whi whi whi whi whi whi whi whi sol blu start switch t1 t5 t3 t4 t2 whi/blu brew timer lef...

  • Page 32: Schematic Wiring Diagram

    Page 32 10693.0000g 02/07 © 1993 bunn-o-matic corporation 120/240 volts ac 3 wire 120 volts ac 2 wire single phase brew timer whi whi whi whi/blu whi/grn sol t1 t2 t3 t4 t5 start switch blu whi/red blk blk blk blk whi/red on/off switch optional automatic brew circuit whi heater switch "keep warm" he...

  • Page 33

    Page 33 auxiliary outlet (200 watt maximum) blk e.R.T assy. 120/240 volts ac 3 wire 120 volts ac 2 wire single phase p1, p2, & p3 are pins of a polarized three-pin connector. Whi blk sol blu blu whi brew timer blk p1 p3 p2 whi optional automatic brew circuit schematic wiring diagram cw-ts & cw-aps e...

  • Page 34

    Page 34 schematic wiring diagram for cwt-aps mv, cwtf-aps mv, cwtf-ts mv, cwtf-tsr mv 41711.1 052009.

  • Page 35

    Page 35 41711.1 052009.

  • Page 36

    Page 36 41711.1 052009.

  • Page 37

    Page 37 41711.1 052009.

  • Page 38

    Page 38 blk 41711.1 052009.

  • Page 39

    Page 39 41711.1 052009.

  • Page 40: Schematic Wiring Diagram

    Page 40 whi/red left lower warmer whi/red whi/grn p1-2 p1-3 p4-2 p4-3 schematic wiring diagram cwt/cwtf twin 0/2, 2/2, 4/2 & cwt twin-aps (faucet) thermal safety fuse blk right tank heater blk blk blk red blu blk blk sw2 rt. Limit thermostat rt. Ready indicator rt. Sw. & thermostat blk 10736.0000l 0...

  • Page 41: Schematic Wiring Diagram

    Page 41 whi/red left lower warmer whi/red whi/grn p1-2 p1-3 p4-2 p4-3 schematic wiring diagram cwt/cwtf twin 0/2, 2/2, 4/2 & cwt twin-aps (faucet) thermal safety fuse blk right tank heater blk blk blk red blu blk blk sw2 rt. Limit thermostat rt. Ready indicator rt. Sw. & thermostat blk 10736.0000m 0...

  • Page 42: Twin 2/2 & 4/2

    Page 42 whi/red whi/grn p1-2 p1-3 p4-2 p4-3 schematic wiring diagram cwtfa twin 2/2 & 4/2 l1 grn/yel l2 l3 right tank heater blk blu rt. Ready indicator rt. Sw. & thermostat red blk sw2 blu rt. Limit thermostat blu 10736.0001g 12/00 © 1993 bunn-o-matic corporation 230 volts ac 3 wire three phase red...

  • Page 43: Schematic Wiring Diagram

    Page 43 blk whi/red whi/grn p1-2 p1-3 p4-2 p4-3 schematic wiring diagram cwtfa & cwtfb twin 2/2 & 4/2 l1 grn/yel l2 (faucet) thermal fuse blk right tank heater blk red blu blk blk sw2 rt. Limit thermostat rt. Ready indicator rt. Sw. & thermostat blk red 10736.0002j 12/00 © 1993 bunn-o-matic corporat...

  • Page 44: Schematic Wiring Diagram

    Page 44 blk whi/red whi/grn p1-2 p1-3 p4-2 p4-3 schematic wiring diagram cwtfa 2/2 twin, cwtfa 4/2 twin & cwtfa twin-aps l1 l2 10736.0004a 02/06 © 2006 bunn-o-matic corporation 230 volts ac 2 wire single phase red red red model 4/2 only not applicable to aps models not applicable to aps models blk s...

  • Page 45: Schematic Wiring Diagram

    Page 45 schematic wiring diagram cwtfa twin-aps ce l1 grn/yel l2 blk 10736.0005b 08/07 © 2007 bunn-o-matic corporation 230 volts ac 2 wire + gnd single phase red sw4 blk whi/grn whi/blu rt sol blu right brew timer red sw6 whi/red whi/red whi/red lt. Tank heater red blu blk sw1 nc nc nc nc lt. Ready ...

  • Page 46

    Page 46 gry pin l.E.D. L.E.D. Gry pin gry pin optional indicator timer whi/red whi/grn p1-2 p1-3 schematic wiring diagram cwtf twin 0/6 (faucet) blk blk right tank heater blk blu blk blk sw2 rt. Limit thermostat rt. Ready indicator rt. Sw. & thermostat blk red left brew warmer right brew warmer whi ...

  • Page 47

    Page 47 whi/blu p3 blk p1, p2, & p3 are pins of a polarized three-pin connector. Blu blu/blk whi brew timer p1 p2 whi optional automatic brew circuit schematic wiring diagram c, ct & cwt 10836.0000h 05/09 ©1995 bunn-o-matic corporation p2 p1 front whi whi p3 whi brn/blk vio whi rear whi whi blk whi/...

  • Page 48

    Page 48 p3 p1, p2, & p3 are pins of a polarized three-pin connector. Blu p1 red optional automatic brew circuit schematic wiring diagram cwtb 10836.0002e 07/00 ©1995 bunn-o-matic corporation p2 p1 front red red p3 red brn/blk vio red rear red red red blk whi/red lower warmer start switch whi/red whi...

  • Page 49

    Page 49 p3 p1, p2, & p3 are pins of a polarized three-pin connector. Blu p1 red optional automatic brew circuit schematic wiring diagram cwta 10836.0003e 07/00 ©1995 bunn-o-matic corporation p2 p1 front red red p3 red brn/blk vio red rear red whi red red blk whi/red lower warmer start switch whi/red...

  • Page 50

    Page 50 p1, p2, & p3 are pins of a polarized three-pin connector. Sol brew timer red red 10836.0004h 10/02 ©1997 bunn-o-matic corporation p2 p1 front warmer red red p3 red brn/blk vio red rear warmer red red whi/red whi/red lower warmer rear warmer red red p3 p1 vio 230 volts ac 2 wire single phase ...

  • Page 51

    Page 51 20 amp t1 t5 t3 t4 t2 41711.1 052009.

  • Page 52: Schematic Wiring Diagram

    Page 52 p3 blk p1, p2, & p3 are pins of a polarized three-pin connector. Whi blk sol blu blu whi brew timer p1 p2 whi optional automatic brew circuit schematic wiring diagram cwtf, cwtfb no warmer 10836.0006m 02/07 ©1995 bunn-o-matic corporation whi blk start switch whi/red whi/red tank heater blk h...

  • Page 53: Schematic Wiring Diagram

    Page 53 ready indicator blk blu sw. & thermostat p3 blk p1, p2, & p3 are pins of a polarized three-pin connector. Whi blk sol blu blu whi brew timer p1 p2 whi optional automatic brew circuit schematic wiring diagram cwtfa no warmer 10836.0008a 12/99 ©1999 bunn-o-matic corporation red blk whi/red whi...

  • Page 54: Schematic Wiring Diagram

    Page 54 t1 t5 t3 t4 t2 blk-14 blk-14 120v ac 2 wire 120/208v ac 3 wire 120/240v ac 3 wire single phase whi-14 whi whi whi whi/red whi/red whi/red whi whi whi whi whi whi whi whi whi/grn whi/blu whi/vio-14 blu-14 red-14 tank heater 1320 w 1800 w tank heater selector switch 10836.0009c 02/07 ©2003 bun...

  • Page 55: Schematic Wiring Diagram

    Page 55 t1 t5 t3 t4 t2 blk-14 blk-14 120v ac 2 wire 120/208v ac 3 wire 120/240v ac 3 wire single phase whi-14 whi whi whi/red whi/red whi whi/grn whi/blu whi/vio-14 blu-14 red-14 tank heater tank heater selector switch 10836.0010b 02/07 ©2001 bunn-o-matic corporation blk blk blk blk blu blu whi/red ...

  • Page 56: Schematic Wiring Diagram

    Page 56 blu whi brew timer schematic wiring diagram single cw 10836.0011b 01/03 ©2003 bunn-o-matic corporation whi whi whi whi blk whi/red lower warmer start switch whi/red whi/red l1 grn blk red (model 35) whi (models 15 & 20) n l2 heater switch blk blu on/off switch whi/red whi whi (faucet option ...

  • Page 57: Schematic Wiring Diagram

    Page 57 blk whi red blu tank heater blk limit thermostat limit thermostat sw1-l sw1-r (faucet side) "keep warm" heater schematic wiring diagram cwtf twin 4/2 & 0/6 two-circuit left right 10847.0000d 01/07 ©1994 bunn-o-matic corporation two individual branch circuits required each rated 120/240 volts...

  • Page 58: W/recovery Booster

    Page 58 p4-2 p4-3 schematic wiring diagram cwt twin 2/2 & 4/2 w/recovery booster red whi whi whi left top warmer right top warmer whi p4-1 yel yel whi/yel whi/yel whi whi red sw7 sw8 blk p5-3 p5-2 10867.0000f 01/07 © 1995 bunn-o-matic corporation 120/240 volts ac 3 wire + gnd single phase red whi wh...

  • Page 59: Recovery Booster

    Page 59 whi/red whi/grn p1-2 p1-3 schematic wiring diagram cwtf twin 0/6 with recovery booster l1 green (faucet) thermal safety fuse blk blk right tank heater blk blu blk blk sw2 rt. Limit thermostat rt. Ready indicator rt. Sw. & thermostat blk red left brew warmer right brew warmer whi p1-1 whi/red...