Hello franjaserra, I’m Chris from the Home Depot’s how-to Community. Thank you for your question.
The Frost King heat cable is controlled by a thermostat. The thermostat turns power to the cable on when the temperature drops to 38 degrees F, and shuts off when the pipe temperature rises to 45 degrees.
You can see more information on these heat cables here:http://static.frostking.com/wp-cont...http://www.frostking.com/