State Industries GSX - Manual (Page 11)

11
Energy Cut Off (ECO): A metal tube (Temperature
Probe) mounted onto the back of the gas control
valve/thermostat is immersed inside the tank water.
The probe acts as a temperature high limit. If water
gets excessively hot, an Energy Cut Off (ECO) switch
within the probe opens, interrupting the small electrical
current to the gas valve, and gas fl ow through the
control is interrupted. NOTE: If this safety sensor opens,
the entire control must be replaced. The ECO is NOT
resettable.
Thermal Cut Off Switch (TCO): The water heater
is also equipped with a resettable thermal switch,
designed to shut off the gas supply in the event the
water heater has been exposed to high combustion
chamber temperatures caused by fl ammable vapors
(e.g. spilled gasoline), poor combustion caused by a
blocked vent or insuffi cient combustion air.
Gas: When you prepare to light the pilot, you are
instructed to turn the gas control knob to the pilot
position and depress the gas control knob (Reset button
on Robertshaw Gas Valves). When depressed gas will
fl ow to the pilot burner only. You then have to (manually)
ignite this pilot gas using the piezo igniter button. When the pilot is lit, the fl ame must heat the thermocouple until
it generates suffi cient voltage to the gas valve to allow you to release the knob while gas continues to fl ow to
the pilot. When the gas control knob is turned to the “ON” position, gas is also available to the main burner if the
thermostat calls for heat.
Water Flow: When a hot water faucet is opened, water pressure from the well tank or street main forces cold
water into the water heater through the dip tube. This pushes hot water out of the tank.
BASIC INSTALLATION & OPERATION
Figure 5
Reset Button
TCO Reset
Button
NOTE: RobertShaw® Gas Control
Valve/Thermostat shown.
Gas Control Valve/Thermostat - Side View
Gas Control Knob
Gas Inlet
Temperature
Probe
Protective
Plastic Sleeve
Thermocouple
Temperature
Sensor ECO
TCO (Thermal
Cut Off) Sensor
TCO (Thermal
Cut Off) Switch