Stove Fan Control
Temperature Range:
Close - 150° F 
Open - 130° F
Close to Rise
Therm-O-Disc Part Number 60T12-610050

These controls remains off until the temperature reaches the CLOSE temperature (shown on the control), upon which the circuit CLOSES; a closed circuit is a complete circuit and it allows for electricity to pass, starting the blower. When the temperature lowers a certain amount (the range next the to close temperature on the control), the circuit OPENS, interrupting the connection and electricity flow, turning the blower off.