The difference between Self-Regulating and Constant Wattage Heating Cables

What exactly is the difference between the two types, and is one more effective?

home with ice cycles on gutter, forming eventual costly hazardsPeople use heating cables in a variety of situations, including floor heating, pipe protection, snow melting, etc. Heating cables are broken down into two categories, self-regulating and constant wattage. Both have the same purpose; however, certain situations will have a better outcome with one type over the other.

heat cable diagram
  • Buss Wires – Carry Electricity to Conductive Core
  • Conductive Core: Colder temperatures allow more energy causing it to heat up. As it heats it expands and allows less energy to pass through. At fifty degrees start up it’s 10 watts/ft. At zero degrees start up it’s 30 watts/ft.
  • Metallic Overshield: Ground wire

Self-regulating heat type uses a conductive core. This core becomes more conductive in colder weather, increasing the wattage used in response to dropping temperatures. This is ideal for homeowners and/or businesses that have annual problems with icicles or ice dam formations on the roof or gutters. During the warmer months, less power is used as the need for wattage is reduced. While these cables do adjust accordingly, they do not turn completely off by themselves and should be used with some form of a controller or thermostat, and a large breaker.

Constant wattage cables use the same wattage throughout the entire length and do not auto adjust. The consistent heat they give makes them the first choice for homeowners looking to maintain heating output. It uses more power, so it must be used with a controller or a thermostat.

Both constant wattage and self regulating heat cables work indoors to heat floors, or melt and deice outdoors. When deciding which is best for roofs and gutters, self-regulating is the most efficient choice due to their ability to eat up even when the outside temperature is cold. Constant wattage cables are the best choice for situations that require snow melt as they are able to keep up with environmental changes.