Bunn Coffee Machine CWTF-TC

Disconnect the water supply tube from the fill basin

Remove the tank inlet fitting securing the fill basin to the tank lid, remove fill basin and tank inlet gasket. Set all three parts aside for reassembly

On brewers with faucet shut-off water supply to the brewer and disconnect the inlet and outlet water lines to the faucet coil assembly

Disconnect the black wire on the limit thermostat from the tank heater switch. On late model brewers also disconnect the blue wire from the limit thermostat to the control thermostat

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

Remove sprayhead and the hex nut securing the sprayhead tube to the hood. Set aside for reassembly

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

Remove the tank lid with limit thermostat, sprayhead tube, tank heater, coil assembly and control thermostat w/bracket (early models only)

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

Disconnect the brewer from the power source

Disconnect the black wire from the limit thermostat

Check the voltage between the black wire removed from the limit thermostat and the white wire or red wire on the tank heater with a voltmeter

Disconnect the brewer from the power source

Check the brewer wiring harness if voltage is not present as described

Check for continuity between the black wire removed from the limit thermostat and the black insert on the terminal block with the tank heater switch in the 'ON' upper position

Continuity should not be present in the 'OFF' lower position

If continuity is present as described, the tank heater switch is operating properly

If continuity is not present as described, replace the tank heater switch

Warning: Disconnect the brewer from the power supply before starting the test

Voltage across the black and white wires on 120 volt models or the black and red wires for 120/240 volt models, 200 volt models and 230 volt models is as expected

If voltage is not as expected, check wiring harness

Continuity across the tank heater terminals

If continuity is not as expected, replace the tank heater

Tank heater has cracks in the sheath?

Sign off on the tank heater test

Warning: Disconnect the brewer from the power supply before starting the test

Brewer disconnected from the power supply

Pink and tan wires disconnected from the switch terminals

Continuity present across the two terminals on the switch when it is in the both positions

Continuity present across these terminals only in the full position

If continuity is not present as described, replace the switch

Warning: Ensure the coffee machine is unplugged before starting the procedure

All wires removed from limit thermostat terminals

Limit thermostat slid out from under the retaining clip and removed

New limit thermostat slid into the retaining clip

Sign off on the limit thermostat replacement