Bunn TWF service manual SERVICE cont, Tank Heater

Models: TWF

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TANK HEATER

SERVICE (cont.)

TANK HEATER

P2198.50

FIG. 24 TANK HEATER

Location:

The tank heater is located inside the tank and se- cured to the tank lid.

Test Procedures:

1.Disconnect the brewer from the power supply.

2.With a voltmeter, check the voltage across the black and white wires on 120 volt models or the black and red wires for 120/208 volt models. Con- nect the brew to the power source. The indication must be:

a)120 volts ac for two wire 120 volt models .

b)208 volts ac for three wire 120/208 volt mod- els.

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 Wir- ing Diagrams and check wiring harness.

4.Disconnect the black wire and the white wire or red wire from the tank heater terminals.

5.Check for continuity 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, re- move and inspect heater for cracks in the sheath.

Removal and Replacement:

1.Disconnect the black wire and the white or red wire from the tank heater terminals.

2.Remove sprayhead and the hex nut securing the sprayhead tube to the hood. Set aside for reas- sembly.

3.Disconnect vent tube.

4.Disconnect and remove the faucet tube.

5.Remove the eight #8-32 nuts securing the tank lid to the tank.

6.Remove the tank lid with limit thermostat, spray- head tube, faucet tube, tank heater and vent tube.

7.Remove the two hex nuts securing the tank heater to the tank lid. Remove tank heater with gaskets and discard.

8.Install new tank heater with gaskets on the tank lid and secure with two hex nuts.

9.Install tank lid with limit thermostat, sprayhead tube, tank heater, faucet tube and vent tube using eight #8-32 nuts.

10.Secure sprayhead tube to hood using a hex nut.

11.Install sprayhead.

12.Connect vent tube to fitting.

13.Connect the faucet tube.

14.Reconnect the wires to the limit thermostat and tank heater. See limit thermostat section in this manual when reconnecting wires.

15.Refer to Fig. 25 when reconnecting the tank heater wires.

BLK to Control

WHI to Power Cord

Thermostat or

(120V Models) or

Thermal Fuse

RED to Terminal

 

Block (120/208V

 

Models)

FIG. 25 TANK HEATER TERMINALS

P1369

 

 

 

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10510

081599

 

 

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Bunn TWF service manual SERVICE cont, Tank Heater