Resetting The Stack Safety Switch; Understanding The Function Of The Stack Safety Switch - Saturn 125 Operator's Manual

Resetting the Stack Safety Switch

WARNING: BURN HAZARD! To prevent serious personal injury, be sure to allow ample time, at
least 30 minutes, for the stack, barometric damper, and switch to cool down before attempting to
access and service these components. It is crucial to identify the cause of the stack obstruction (e.g. heavy
snowfall) and correct it before resetting the stack safety switch and re-starting the burner. DO NOT operate
the heating equipment with an obstructed stack; failure to correct an obstructed stack may result in fire,
explosion, and/or burn hazards causing serious personal injury or death.
NOTE: In locations where heavy snowfall occurs, it is critical that the stack remain unobstructed by snow.
For safe heating equipment operation, be sure to keep the area surrounding the stack clear of snow.
1. Before resetting the stack safety switch, check the stack to make sure it is clear of any obstructions.
2. Remove the cover from the stack safety switch, and push the small button in the middle of the switch.
3. Pushing the stack safety switch reset button will re-establish the thermostat circuit, and the burner will
start (assuming the wall thermostat is calling for heat).

Understanding the Function of the Stack Safety Switch

The Stack Safety Switch monitors the temperature at the barometric damper on the stack and is designed to
detect the obstruction of the free flow of stack gases from the heating equipment and shut down the burner.
Obstruction of the stack results in the "spillage" of stack gases from the barometric damper, which heats up the
switch. The switch then opens, disconnecting the thermostat circuit to the burner, and the burner shuts off.
Stack Safety Switch Specifications
Switching Voltage
Switch OPEN Temperature
Switch Type
Operator's Manual: Models Saturn™ 140 & Saturn™ 230
24 volts
180 degrees F
L180, normally closed, manual reset
WALL
THERMOSTAT
STACK
SAFETY
SWITCH
(MOUNTED ON
BAROMETRIC DAMPER)
Figure 4P - Stack Safety Switch Wiring Diagram
OIL
PRIMARY
I88965
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