Bunn Brewer ST

Disconnect the brewer from the power source

Disconnect the wires from the solenoid valve. With the 'ON/OFF' switch in the 'ON' upper position press the start switch

Check the voltage across the two wires with a voltmeter. Connect the brewer to the power source

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 Wiring Diagrams and check brewer wiring harness

Check for continuity across the solenoid valve coil terminals

If continuity is present as described, reconnect the wires to the solenoid. If continuity is not present as described, replace the solenoid valve

Check the solenoid valve for coil action. Connect the brewer to 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

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

WHI wire connected to the terminal block and the wire from the warmer element to the 'ON/OFF' switch

Voltage across the WHI wire from the terminal block and the wire from the 'ON/OFF' switch to the warmer element

If voltage is not present as described, check brewer wiring harness

Continuity across the two terminals on the warmer element

If continuity is not present as described, replace the warmer element

Sign off on the Brewer Warmer Elements Test

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

Brewer disconnected from power source

Thermal cutoff disconnected from the tank heater terminal and the limit thermostat or wiring harness

Continuity across the thermal cutoff terminals checked using an ohmmeter

If continuity is not present, replace the thermal fuse

Sign off on the Brewer Thermal Cut-Off Test

Remove the three #4-40 screws securing the warmer assembly to the brewer

Lift the warmer assembly from the brewer

Disconnect the two wires from the warmer element terminals

Remove the two #8-32 nuts securing the warmer element to the warmer plate

Securely install new warmer element

Reconnect the two wires to warmer element terminals

Securely install warmer assembly on the brewer

Sign off on the Brewer Warmer Elements Replacement

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

White or red wire removed from the upper terminal and black wire from the center terminal

Voltage across the white or red wire and the black wire

If voltage is not as described, check the brewer wiring harness

White/red wire for the lower warmer switch, the brown/black wire for the top front warmer switch or the blue/black wire for the top rear switch removed from the lower terminal

Continuity present across the center and lower terminal with the switch in the 'ON' position

Continuity not present when the switch is in the 'OFF' position

If continuity is not as described, replace the switch