APW Wyott GGT-18H CALIBRATION PROCEDURE FOR GGT GRIDDLES Locate the reading positions, Example

Flame extinguished 367ºF Flame ignition 341ºF 708º / 2

Average temperature = 354ºF

CALIBRATION PROCEDURE FOR GGT GRIDDLES

Locate the reading positions

Make sure the griddle surface is clean. Grease or food particles on the griddle will result in inaccurate thermostat calibration.

Mark the locations where the temperature probe will be placed for testing. See the sketch provided. Starting from the left side of the griddle measure 8” to the right and 10-5/8” from the rear splash guard. With a felt tip pen mark this location. This is the location directly over the center of the left thermostat bulb. From this point measure right 10” remaining 10-5/8” from the rear splash guard. Mark this location with a felt tip pin. This is the location over the next thermostat bulb. For a 36” GGT repeat this one more time 10” to the right and for the 48” GGT repeat this twice more 10” to the right always remaining 10-5/8” from the splash guard. After all locations are marked center the temperature probe on each marked location, and then trace a circle around the probe.

This procedure will place the temperature probe over the center of each thermostat bulb, and this is the only place temperature readings should be taken.

Set all thermostats to 350ºF and allow them to cycle three to four times, or allow the griddle to preheat for ½ hour before proceeding. This makes sure the griddle temperatures have saturated the surface.

Determine the differential

Note the temperature for each section of the griddle as the burners ignite. Note the temperature for each section of the griddle as the flame extinguishes.

The flame extinguish temperature minus the ignition temperature equals the differential.

EXAMPLE: Flame extinguished 367ºF Flame ignition 341ºF Difference 26º F = Differential

If the temperature differential is large than 75ºF, there is probably a problem with your system. It may not be the thermostat. First make sure you thermostat probe is flat against the griddle plate and is making good contact. Dirt under the probe will cause inaccurate readings. Next make sure the thermostat bulb is held tightly in its holder. If you can pull the capillary tube and the bulb moves it is not held tight enough against the griddle plate. This will cause variations in the temperature of the griddle surface. If both of these items have been checked and you still have a differential over 75ºF then the thermostat is bad replace it.

Determine the average temperature

Note the temperature for each section of the griddle as the burners ignite. Note the temperature for each section of the griddle as the flame extinguishes.

The flame extinguish temperature plus the flame ignition temperature divided by two equals the average temperature.

EXAMPLE:

If the average temperature is within 15ºF of the dial marking you probably leave the calibration where it is. If the average temperature is outside of 15ºF of the dial setting you will want to calibrate the thermostat. To calibrate a thermostat first remove the knob by pulling it straight off the shaft. Next take a small flat head screw drive and turn the screw inside the shaft, clockwise to decrease, counterclockwise to increase. ¼ turn clockwise will decrease the temperature approximately 24ºF. ¼ turn counterclockwise will increase the temperature approximately 24ºF. Adjust and re-measure the average temperature until you get the temperature to your desired point.

NOTE: avoid making more than ½ turn at a time. Calibration is not linear and you can get the thermostat significantly out of calibration to a point where it is difficult to reset.

If after adjusting the thermostat three times and getting no change in calibration the thermostat is bad. Then replace the thermostat.

9