Griddles with BJWA Thermostat
Before attempting recalibration on the BJWA thermostat, a temperatures check must be done from a cold start, before the griddle has been idling and the temperature has had a chance to creep up. All temperature readings and/ or calibrations must be performed from a cold start. Thermostats can be rendered inoperative by improper calibration and/or adjustments.
•Clean the griddle plate and make sure there is no carbon buildup on the cooking surface. Carbon buildup will cause a false temperature reading.
•Remove the temperature dials and manifold cover. Locate sensor probes. Temperature readings can only be taken directly over the sensor probes. The sensor probes will be located as follows. Approximately 6" from the left side splash, then 12" spacing and the last sensor probe will be approximately 6" from the right side splash (Diagram #11).
•Once the left
•Pull off all the thermostat dials. Using a screwdriver from the back of the dial, push out the center chrome cap of the dial. Replace dial on the thermostat.
•Turn the dial to 300°F. The flame should be approximately 3/4" to 1" tall. Allow about 15 minutes for plate to heat up.
•Turn the dial to the lowest temperature setting (150°F). Check the bypass flame; it should be only big enough to keep the burner lit all the way around (little blue dots of flame). Adjust as necessary (Diagram
# 12).
•Take note of the size of the bypass flame, as it will be necessary to recognize when the thermostat is in bypass throughout the calibration process.
•Turn the dial up enough for the flame to come on at least 1/4" tall. When the flame is in bypass, again take a temperature reading in the area previously identified as the probe location. If the temperature is more than 25°F different from the dial setting, calibrate as follows.
•With the dial in place, use a small screwdriver through the opening in the front of the dial locate and depress calibration screw, Do not turn the calibration screw. Rotate the dial to match the actual temperature on the griddle plate. Release the calibration screw.
•Turn the dial to increase the temperature 50°F. Watch flame and as soon as the flame is again in full bypass, take a temperature reading. If the temperature is more than 25°F different than the dial setting, the thermostat may need to be replaced.
•Once the thermostat is determined in calibration, that thermostat should be turned off so as not to cause false readings on the other zones.
•Repeat the process for each thermostat zone.
•Once all the thermostats are calibrated, reassemble the dials and reinstall the manifold cover and the thermostat dials.
NOTE: Although the BJWA thermostat is a very simple and basic thermostat, it is somewhat difficult to calibrate due to the fact that once the bypass is set, it must be recognized as in full bypass at the time the temperature reading is taken. Additionally, if the temperature reading is not taken as soon as the thermostat is in full bypass, the temperature will begin creeping up and a true temperature reading will not be possible.
In the event a thermostat has to be replaced, use extreme care when handling and installing the sensor probe. Do not kink or severely bend the probe. Do not allow direct flame to come in contact with the probe or the capillary line. Any excess capillary line should be gently coiled up in an area that is away from direct flame and/or working or cleaning areas. Warranty does not cover thermostats that have been rendered inoperative by improper adjustments and/or calibrations or by work being performed by unqualified personnel.
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