bbq factory Magnetic Thermostat Switch for fireplace fan / fireplace blower kit Magnetic Thermostat Switch for fireplace fan / fireplace blower kit Magnetic Thermostat, NO Bracket Needed. Thermostat Temperature Activate approximately at 120F / 50C, shutoff approximately at 90F / 32C NOTE: Blower will not Start until thermostat is heated to approximately 120 F.