Raychem self-regulating electric heat trace cables automatically adjust their power output to compensate for temperature changes. Heat is generated as electric current passes through the conductive polymer core between the conductors. As the temperature drops, the number of electrical paths through the core increases and more heat is produced. Conversely, as the temperature rises, the core has fewer electrical paths and less heat is produced 

Raychem WinterGard Wet and Gardian self-regulating heat trace cables:

• Can be used for metal or plastic gutters or downspouts
• Have a cross-linked, conductive polymer core forming a parallel circuit
• Are protected by a tinned-copper braid and are available with a durable outer jacket to withstand mechanical abuse during installation

Raychem WinterGard Wet can be cut-to-length, whereas Gardian is a pre-terminated heat trace cable connected to a 30-inch power cord.

Pentair Thermal Management offers thermostats and controllers to meet a variety of roof de-icing requirements:

• Has a fixed set point of 40°F (5°C)
• Can be used for ambient or line-sensing

• Controllers that trigger the system to energize when both moisture and low temperatures are detected