INSTALLATION AND OPERATION MANUAL, GAS KETTLE, MODEL GL-30
10156R2
23
2012-11-28
6.0 SERVICE
(Continued)
THERMOSTAT
The thermostat adjustment should not be changed. Check the following before changing the
thermostat:
1. With kettle cool, the pressure reading on the pressure gauge should be in the green
vacuum zone (below 0 psi). If not, see “Re-establishing Vacuum” section.
2. Check that the pressure switch is not set too high or too low and causing the out of
adjustment condition. A voltmeter should be used by a properly trained serviceman to
determine if the pressure switch or thermostat is actually cycling the burners. If the
pressure switch is found to be the problem, see “Pressure Switch” section.
After verifying that the pressure switch is set and operating properly, the thermostat may be
adjusted using the set screw inside the stem. The thermostat should cycle off at a gauge
pressure reading of 30 psi. Turn set screw clockwise to decrease pressure and
counterclockwise to increase pressure.
PRESSURE SWITCH
The pressure switch should not be adjusted until it is determined to be the cause of an
operating pressure deficiency. See “Thermostat” section to determine if the source of difficulty
is the pressure switch or thermostat.
The major difficulties caused by pressure switch mis-adjustment are:
1. Pressure relief valve opening, especially on preheat from a cold start to 275 degrees
Fahrenheit (135°C) (pressure switch set too high).
2. Burners are being shut down by pressure switch, not the thermostat. (Pressure switch
set too low.)
The pressure switch is preset for proper operation from the factory. It is adjusted to the
maximum pressure, however not high enough to cause the pressure relief valve to open. This
setting will be slightly different on different kettles due to variations in the pressure relief valves.
During preheat to the maximum thermostat setting (275 degrees Fahrenheit) (135°C), from
either a cold condition or a lower temperature setting, the temperature may overshoot the
thermostat setting and shut down the burners by the pressure switch. This is normal, however,
after the kettle cycles several times (empty) the thermostat will begin cycling the unit.
