Bunn Hot Water Dispencer H3X

Warning: Ensure the device is unplugged before starting the procedure

All wires removed from the electronic control board terminals

Six 6-32 screws removed from the electronic control board

Temperature sensor, overflow tube temperature sensor, and indicator wires disconnected from the electronic control board

Temperature sensor, overflow tube temperature sensor, and indicator wires attached to the new electronic control assembly

New electronic control board fastened to its bracket

Upload a photo of the reconnected wires

Refer to Fig 2 when reconnecting the wires

Review the initial set-up procedures on page 6

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

Check the voltage across terminals 3 & 4 of the electronic control board with a voltmeter. The indication must be: a.) 100 to 120 volts ac for 100 to 120 volt models b.) 200 to 240 volts ac for 200 to 240 volt models c.) 230 volts ac for 230 volt models

Check the dispenser wiring harness if voltage was not present as described

Remove the pink wire from terminal 5 of the electronic control assembly

Check the voltage across terminals 1 & 4 of the electronic control board with a voltmeter. The indication must be: a.) 100 to 120 volts ac for 100 to 120 volt models or b.) 200 to 240 volts ac for 200 to 240 volt models or c.) 230 volts ac for 230 volt models after a delay of approximately 5 seconds

Replace the electronic control board and the temperature sensor in the tank lid if voltage was not present as described

Reconnect the pink wire to terminal 5 of the electronic control assembly

Loosen the compression fitting, remove the probe from the tank lid, and inspect it for mineral deposits. Replace it if necessary. Keep the exposed ends of the probe away from any metal surface of the dispenser

Check the voltage across terminals 1 & 4 of the electronic control assembly with a voltmeter. The indication must be: a.) 100 to 120 volts ac for 100 to 120 volt models or b.) 200 to 240 volts ac for 200 to 240 volt models or c.) 230 volts ac for 230 volt models after a delay of approximately 5 seconds

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

Voltage across terminals 3 & 4 of the electronic control circuit board

Voltage across the tank heater terminals

Was the voltage present as described?

If voltage was not present as described, contact Bunn-O-Matic to order an electronic control board and temperature sensor for evaluation

Replace the electronic control board

Voltage across the tank heater terminals after replacing the electronic control board

Was the voltage present as described after replacing the electronic control board?

Disconnect the dispenser from the power source

Disconnect the black wire from the contactor coil to the limit thermostat and black wire from the red wire on the main harness on two wire 240V models

Check the voltage across the red wire and black wire with a voltmeter

Disconnect the dispenser from the power source

If voltage is present as described, proceed to #5. If voltage is not present as described check the wiring harness

Check for continuity between the left and right terminals on the contactor coil

If continuity is present as described, reconnect the wires and proceed to #6. If continuity is not present as described, replace the contactor

Disconnect the dispenser from the power source

Remove the top cover (3 screws) and front shroud assembly (4 screws)

Remove the top 2 screws and loosen 2 lower screws securing control panel to shroud

Disconnect switch wires from the CBA

Remove the large nut securing the switch

Installation in the reverse order

Sign off on the Dispense Switch Replacement