Bunn H5X Service & Repair Manual page 10

SERVICE (cont.)
Electronic Controls (cont.)
7. Reconnect the pink wire to terminal 5 of the elec-
tronic control assembly.
8. Loosen the compression fitting, remove the probe
from the tank lid, and inspect it for mineral depos-
its. Replace it if necessary. Keep the exposed ends
of the probe away from any metal surface of the
dispenser.
9. Check the voltage across terminals 1 & 4 of the elec-
tronic control assembly with a voltmeter. Connect
the dispenser to the power source. 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.
10. Touch the screw head end of the probe to the dis-
penser housing. The indication must be 0.
11. Move the probe away from the dispenser housing.
The indication must again 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.
12. Disconnect the dispenser from the power source.
H5X THERMOSTAT
H5/10X THERMOSTAT
PROBLEM: Boils Excessively - Fills Cup
Drain cup
Retry
Yes
Red Light On While
Replace Steam Sensor
Boiling
?
No
Disconnect Blue Wire From
Control Board Pin 7
Retry
Yes
Still Boiling
?
Replace Triac Assembly
No
Replace Control Board
Yes
Still Boiling Replace Control Assembly
?
No
Finished
Check For Split
Tank Heater
Temperature Control Flow Charts (cont.)
If voltage was present as described, reinstall the probe,
the sensing function of the system is operating properly.
If voltage was not present as described, check the pink
probe wire and the green ground wire for continuity
and/or replace the probe.
Temperature Control Test Procedure
1. Disconnect the dispenser from the power source.
2. Check the voltage across terminals 3 & 4 of the
electronic control circuit board with a voltmeter.
Connect the dispenser to the power source.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.
3. Disconnect the dispenser from the power source.
4. Check the voltage across the tank heater terminals
with a voltmeter. Connect the dispenser to the
power source. 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.
5. Disconnect the dispenser from the power source.
H5E THERMOSTAT
H3/5E THERMOSTAT
PROBLEM: Boils
Drain cup
Retry
Red Light On While
Boiling
?
No
Disconnect Blue Wire From
Control Board Pin 7
Retry
Still Boiling
?
No
Replace Control Board
10
Yes
Replace Control Assembly
Yes
Replace Triac Assembly
Check For Split
Tank Heater