#834 Operation & Care Manual - 5.
THERMOSTAT & PILOT LIGHT
SEQUENCE
Whenever the start-up procedure has been completed, the
indicator light will indicate the power ON/OFF condition of the
heating cable and consequently, the cycling of the oven as it
maintains the dialed cavity temperature. If the indicator light
does not indicate after normal start-up, the main power source
and/or the main power breaker, and/or the oven’s control cir-
cuitry must be checked. If a oven compartment does not hold the
temperature as dialed, calibration of the thermostat must be
checked. (See the paragraph on thermostat calibration.) If a
cooking compartment fails to heat or heats continuously with the
thermostat off, the thermostat must be initially checked for prop-
er operation. If all is in order, a continuity and resistance check of
the heating cable should be made. (See the circuit diagram.)
THERMOSTAT CALIBRATION
AT 250° F COOK (212° C) AND 140° F (60° C) HOLD
The thermostat is precision calibrated at the factory.
Normally, no adjustment or recalibration is necessary unless
the thermostat has been mishandled in transit or changed or
abused while in service. A thermostat with a sensing bulb
operates on hydraulic pressure. Consequently, any bending of
the bulb results in a change in its volume and displaces the
accuracy of the thermostat calibration.
A thermostat should be checked or recalibrated by placing
a quality temperature indicator at the center of an empty oven
cavity. DO NOT CALIBRATE WITH FOOD PRODUCT IN
THE OVEN. The temperature must be allowed to stabilize at
one particular setting for at least two hours. The center of the
thermal swing of the cavity temperature should approximately
coincide with the thermostat setting.
The calibration screw of the thermostat is located in the
dial shaft. With the shaft held stationary, a minute clockwise
motion of the calibration screw appreciably lowers the thermo-
stat setting while a reverse motion results in the opposite condi-
tion. After achieving the desired cycling of the thermostat, the
calibration screw must be sealed in place with a few drops of
sealant. (R
ED NAIL POLISH OR EQUIVALENT IS ACCEPTABLE.)
TROUBLE SHOOTING CHECK LIST
TROUBLE POSSIBLE CAUSE REMEDY
Unit does not operate. Insufficient electric power unit. Check power source.
Defective plug or cord. Check and repair if necessary.
Power switch defective. Replace.
Cooking temperature not correct. Cook thermostat out of calibration. Calibrate.
Holding temperature not correct. Hold thermostat out of calibration. Calibrate.
Timer runs down, but oven will not Timer not de-energizing cook circuit. Replace timer.
go into HOLD.
Cook thermostat erratic — will not Cook thermostat. Replace thermostat.
hold calibration.
Hold thermostat erratic — will not Hold thermostat. Replace thermostat.
hold calibration.
Oven goes from cooking temperature Hold thermostat. Replace hold thermostat.
to cold.
Oven will not go into cook cycle when Timer or contactor. With timer turned ON, line
timer and cook thermostat are ON. voltage should appear across
term. 2 and 3 of timer. If not,
replace timer.
If line voltage does appear
across term. 2 and 3 of timer, it
should also appear across
holding coil of contactor.
If line voltage does appear
across holding coil, and it
won’t close its contacts,
replace contactor.
It takes too long to cook Heating element open, resulting in Replace element.
(temperature O.K.). low wattage.
Cannot control temperature but Heating element grounded. Replace element.
thermostats check O.K.
DISCONNECT CABINET FROM
THE POWER SOURCE BEFORE
CLEANING OR SERVICING.
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