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Page 16

SERVICE (cont.)

LIMIT THERMOSTAT

FIG. 4 LIMIT THERMOSTAT

P1798.40

Location:

The limit thermostat is located inside the hood on

the tank lid.

Test Procedure:
1. Disconnect the brewer from the power source and

remove the blue wire from the limit thermostat.

2. With a voltmeter, check the voltage across the blue

wire removed from the limit thermostat and the
white wire on the tank heater terminal. Connect
the brewer to the power source. The indication
must be 120 volts ac for two wire120 volt mod-
els.

3. Disconnect the brewer to from the power source.

If voltage is present as described, reconnect the blue
wire and proceed to #4.
If voltage is not present as described, refer to the 

Wir-

ing Diagrams and check the wiring harness.

4. Remove the black wire from the limit thermostat.

5. With a voltmeter, check the voltage across the ex-

posed terminal of the limit thermostat and the
white wire on the tank heater terminal. Connect
the brewer to the power source. The indication
must be 120 volts ac for two wire 120 volt mod-
els.

6. Disconnect the brewer from the power source.

If voltage is present as described, reconnect the black
wire to the limit thermostat.  The limit thermostat is
operating properly.
If voltage is not present as described, replace the limit
thermostat.

Removal and Replacement
1. Remove both wires from the limit thermostat ter-

minals.

2. Carefully slide the limit thermostat out from un-

der the retaining clip.

3. Carefully slide the new limit thermostat into the

retaining clip.

4. Refer to Fig. 5 when reconnecting the wires.

BLU to Control
Board N.O.

BLK to Tank Heater

FIG. 5 LIMIT THERMOSTAT TERMINALS

P1800

29460  061599

Summary of Contents for TU3Q-EZ

Page 1: ...UNN BUNN O MATIC CORPORATION TU3Q EZ POST OFFICE BOX 3227 SPRINGFIELD ILLINOIS 62708 3227 TELEPHONE 217 529 6601 FAX 217 529 6644 29460 0000C 8 00 1999 Bunn O Matic Corporation OPERATING SERVICE MANUA...

Page 2: ...s 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...

Page 3: ...0000 USER NOTICES Carefully read and follow all notices on the equipment and in this manual They were written for your protec tion All notices on the equipment should be kept in good condition Replace...

Page 4: ...pressure between 20 138 and 90 psi 620 kPa from a 1 2 or larger supply line A shut off valve should be installed in the line before the brewer Install a regulator in the line when pressure is greater...

Page 5: ...and momentarily press the START switch 5 Water will flow into the tank and dispenser for approximately three and one half minutes Empty the dis penser when the first cycle stops and press the START sw...

Page 6: ...he sprayhead The holes must be open and clear of any mineral deposits Wipe the sprayhead panel clean with a damp cloth 3 Insert the deliming spring into the sprayhead fitting until no more than two in...

Page 7: ...lace the ON OFF switch in the ON upper position Press and hold the START switch until you hear the solenoid click on and off three times approximately 5 seconds then release the START switch immediate...

Page 8: ...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...

Page 9: ...block The indicator lamp must be lit Refer to Service Start Switch for testing procedures See page 18 Allow brewer to heat until ready lamp is lit or disable the brew lock out feature See page 7 Refe...

Page 10: ...posits Delime as required Refer to Service Brew Solenoid Valve for testing procedures See page 15 A Direction of flow arrow must be pointing towards brewer B Remove strainer flow control and check fo...

Page 11: ...ing must not be less than 5 F 3 C below set temperature Ad just the temperature setting to in crease the water temperature Re fer to Adjustments and Optional Settings See page 7 BUNN paper filters mus...

Page 12: ...Water must be within one inch from top of tank Refer to Service Temperature Probe for testing procedures See page 20 Refer to Service Limit Thermostat for testing procedures See page 16 Refer to Serv...

Page 13: ...t off Level probe dry for 7 minutes after fill valve is energized Shorting pin on J6 connector of control board not on correct set of pins See page 7 Level probe wiring Temperature probe wiring Fill v...

Page 14: ...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...

Page 15: ...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...

Page 16: ...ring harness 4 Remove the black wire from the limit thermostat 5 With a voltmeter check the voltage across the ex posed terminal of the limit thermostat and the white wire on the tank heater terminal...

Page 17: ...present as described proceed to 6 If voltage is not present as described refer to the Wir ing Diagrams and check the wiring harness 6 Check for continuity across the center and end terminals of the to...

Page 18: ...switch is held in the lower po sition Continuity must not be present across these terminals in the upper position If continuity is present as described the switch is operating properly If continuity...

Page 19: ...the sheath Removal and Replacement 1 Disconnect the black wire and the white wire from the tank heater terminals 2 Remove sprayhead and the hex nut securing the sprayhead tube to the hood Set aside f...

Page 20: ...l and Replacement 1 Disconnect the brewer from the power source 2 Pull the existing probe from the tank lid 3 Cut the white and black wires close to the probe and discard the probe Do not disconnect t...

Page 21: ...8 pin connector J 1 and the 6 pin connector J 5 from the main wiring harness 4 Disconnect the 2 pin connector J 7 from the ready indicator LED FIG 15 BOARD WIRING P1803 75 5 Remove the four 6 32 screw...

Page 22: ...Page 22 29460 082300...

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