"ON" AT 115℉ - Temp sensor will turn your fireplace blower fan "on" when it reaches 115 degrees Fahrenheit. "OFF" AT 90℉ - Temp sensor will turn your blower fan "off" when it reaches 90 degrees Fahrenheit. CENTER DISC - Measures 1/2" in diameter. MOUNTING BRACKET - Center Hole to Center Hole measures 1-1/2". Overall Bracket is 2" End to End. 115 VOLT / 2 TERMINALS - Interrupts the Black power wire to your fireplace blower. May be used in conjuction with a speed control. The Midwest Hearth thermal switch (also known as a temp sensor or "snap-stat") can automatically control the on/off function of your fireplace blower fan.

TEMPERATURE RANGE: The switch will "close" at 115℉ which allows power to the fan and turns it "on". When the appliance temperature drops to 90℉ the switch will "open" and stop power to the fan shutting it "off".

WHEN USING AN OPTIONAL SPEED CONTROL: Simply set your preferred fan speed on the rheostat and leave it there. When the fireplace reaches 115℉ the blower will automatically turn on and run at the speed you set on your speed control.

LINE VOLTAGE: This switch is rated to run on standard household (plug in) voltage. IE: 115-120 VAC. This is the voltage almost all fireplace blower fans use for operation.

15 AMP MAX: That's 1800 watts at 120v... More than adequate for single and dual fireplace blowers.