Nu-Vu SUB-123 Owner's Manual page 32

TROUBLE-SHOOTING GUIDE
C. Check the electrical connections between the Power Terminal Block [1], the Power Switch, the
Proofer Temperature Control Circuit Board [8] and the Heating Elements. All connections must
be clean and tight.
D. Check the voltage from the Power Terminal Block to the Power Switch, the Temperature Control
Circuit Board and the Heating Elements. The voltage should match the requirements listed on the
equipment label. If voltage is present at the Heating Elements one or more of the Elements may
be burned out. If voltage is present at the input side of the Temperature Control Circuit Board but
not at the output side, the Control Circuit Board or its Control Sensor [9] may be bad.
E. Check the Temperature Control against a reliable thermometer. Place the thermometer on a Shelf
in the center of the Proofer, turn the Humidity Control [34] to OFF, and set the Temperature
Control to 100 ° . Compare the thermometer reading against the Temperature Control setting
when the Temperature Control Indicator Light [35] goes out. If there is more than 5 ° difference
the Temperature Control may need a simple adjustment (refer to TEMPERATURE CONTROL,
How to Adjust in the SERVICE AND REPLACEMENT GUIDE).
III. The Proofer Power Switch is in the ON position, you have lights, heat and Proofer
Motor rotation but no humidity:
For the standard Manual Fill Proofer:
A. Make sure the Water Pan [64] contains at least 2" of warm water.
B. Make sure the Water Pan is fully seated on the Humidity Element [13].
C. Turn the Humidity Control [34] to #7 or #8 to see if the Humidity Control activates. If the
Humidity Control activates the coil of the Humidity Element should become very hot in only a
few moments; after a minute or two it should be "red-hot".
D. Check all electrical connections between the Proofer Power Switch, the Humidity Control
Circuit Board [10] and the Humidity Element. All connections must be clean and tight.
E. Check the voltage from the Power Terminal Block [1] to the Power Switch, to the Humidity
Control Circuit Board, and to the Humidity Element. If the correct voltage is present at the
Humidity Element but it does not get hot the Element must be replaced (refer to HUMIDITY
ELEMENT, How To Replace in the SERVICE AND REPLACEMENT GUIDE). If voltage is
present at the input side of the Control Circuit Board but not at the output side the Control
Circuit Board or the Humidity Control Sensor [11] may be bad.
For the optional AUTOMIST Proofer:
A. Check for adequate and sustained pressure in the water supply line to the Proofer up to the Water
Solenoid Valve [84]. If there is sufficient pressure at the water source but not at the Solenoid, the
in-line filter may be clogged or the water supply line may be kinked, pinched or otherwise
damaged.
B. Gently tap the Solenoid Valve body to loosen any sediment that may be causing the Valve to
stick closed.
C. Remove the Proofer Element Cover [88] to expose the Injection Nozzle [85] in front of the
Blower Wheel [86]. Unscrew the spray head of the Nozzle and check for clogging in the spray
orifice. Clean the internal screen with a small stiff brush before replacing the spray head.
D. Check all electrical connections between the Proofer Power Switch [31], the Humidity control
[81], the Repeat Cycle Timer [83] and the Water Solenoid Valve. All connections must be clean
and tight.
E. Check the Humidity Control, the Repeat Cycle Timer and the Solenoid Valve with a voltmeter or
ohmmeter for proper operation. Any suspect component should be thoroughly checked. All
nonfunctional components must be replaced.
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NU-VU FOOD SERVICE SYSTEMS
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SUB–123 OWNER'S MANUAL
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