Bunn SA, STA, STFA service manual SERVICE cont, Control Thermostat

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SERVICE (cont.)

SERVICE (cont.)

CONTROL THERMOSTAT

BU

NN

HI

P1585

FIG. 2 CONTROL THERMOSTAT

Location:

Models S & SA: The control thermostat is mounted on a bracket inside the rear inspection cover on the left side.

Models ST, STA, STF & STFA: The control ther- mostat is located inside the front inspection cover on the component mounting bracket.

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 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 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)200 to 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.

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29251 052500

 

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Contents BUNN S,SA POST OFFICE BOX SPRINGFIELD, ILLINOISFAX ST,STA STF,STFAWARRANTY USER NOTICES#00882.0000 USER NOTICES Continued#00656.0000 #02763.0000 #02765.0000 #02769.0000Electrical Hook-Up ELECTRICAL REQUIREMENTSPLUMBING REQUIREMENTS Models S & SA4B. Models ST, STA INITIAL SET-UP4A. Models S & SA 4C. Models STF & STFASTART SWITCH CLEANINGModels ST, STF, STA & STFA ON/OFF SWITCH OPERATING CONTROLSTROUBLESHOOTING PROBABLE CAUSE TROUBLESHOOTING contPROBLEM REMEDYTROUBLESHOOTING cont PROBLEM Dripping from sprayhead Beverage overflows dispenser cont Weak beverage Brewer is making unusal noises Contents SERVICECOMPONENT ACCESS SERVICE cont CONTROL THERMOSTATSERVICE cont CONTROL THERMOSTAT cont SERVICE cont LIMIT THERMOSTAT ON/OFF SWITCH Models ST, STA, STF & STFA FIG. 8 SOLENOID START SWITCH Models ST, STA, STF & STFA SERVICE cont TANK HEATER SERVICE cont TANK HEATER Cont FIG. 14 BREW TIMER SERVICE cont BREW TIMER Early Modelscont DIGITAL BREW TIMER Late Models FIG. 16 DIGITAL BREW TIMERSERVICE cont DIGITAL BREW TIMER Late Modelscont LIQUID LEVEL CONTROL BOARD Models STF & STFA STFACont SERVICE cont TIMER RELAY Models STF & STFA SERVICE cont WARMER ELEMENTS SERVICE cont THERMAL CUT-OFFModels SA, STA & STFA Page 29251Page 29251Page 29251Page 29251Page 29251Page 29251Page 29251Page 29251Page 29251Page 29251Page 29251Page 29251Page 29251