Bunn Fast Cup Series Service & Repair Manual page 98

REAR PANEL
Limit Thermostat
Purpose:
In the event of a tank over heating or a high
current condition exists, the limit thermostat will open at
230° Fahrenheit to prevent the water system from exces-
sive high temperature & pressure.
A limit thermostat is installed on each conductor line
(L1 & L2) going to the heating element. In the event of a
tripped limit thermostat, diagnosis and repair, the limit
will need to be mechanically reset by pushing on the
center button/tab.
TEST INSTRUCTION
Volt/Ohm Meter - Continuity Check
Step 1: Disconnect or unplug machine from power.
Step 2: Remove rear panel to access tank module.
Step 3: Isolate the corresponding tank with the
limit thermostats in preparation of checking
continuity by disconnecting the wires from
both limit thermostats..
Step 4: Select the lowest resistance (OHMS) range
on the voltmeter. Install black meter lead in
the meter COM terminal and red meter
lead in the terminal labeled with the OHM
symbol.
Note: Various voltmeters may have a sym-
bol to indicate audible tone or sound. The
meter will alert with a loud tone or sound to
indicate continuity.
Step 5: Install red meter lead on limit thermostat
terminal and the black meter lead on the
remaining limit thermostat terminal.
Step 6: The voltmeter should display 0.00 or
audible tone will sound to indicate
continuity.
Step 7: No continuity - Reset limit thermostat by
pushing in the center tab. Repeat continuity
check procedure.
No continuity after reset - Replace limit
thermostat and further diagnose heating
circuit.
SERVICE
98
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