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GP Self-regulating Cable for Gutters and Downpipes

CRJ Pipe Freeze Protection Cable
  • Stops the accumulation of ice in gutters and downpipes
  • Ensures that rain and melt-water can drain away normally and not cause damage to properties
  • Reduces risks from collapsing gutters and falling icicles.

Range & Prices

The prices shown are list prices and perfectly safe to use for budget purposes. Contact your electrical wholesaler for final prices.

  Model Description List Price
GP-18 Self regulating cable GP-18 Self-regulating cable  (supplied by the metre) £21.00
THK 01 THK Termination kit (one per circuit) £52.00
THJ 01 2 THJ Junction Box IP66 6-way terminal block 40A max. £45.00
GP-S Spacer kit GP-S Spacer kit (5 stainless steel spacers and 10 cable ties) £38.00
FST2-EX Frost Thermostat for external use FST2-EX Weatherproof Frost Thermostat £173.00

Technical Specification

GP-18 cable

Voltage: 230V
Nominal output at 0°C in ice water: 36W/m
Nominal output at 0°C in air: 18W/m
Minimum installation temperature: -40°C
Maximum exposure temperature (power on): 60°C
Maximum exposure temperature (power off): 85°C
Minimum bending radius: 35mm
Maximum circuit length: 90m


  • Tin coated copper bus wires
  • Self-regulating polymer with bonded jacket
  • Thermoplastic insulation
  • Tin coated copper earth braid
  • UV resistant thermoplastic overjacket

Maximum Length (m) / Circuit Breaker Size (type C)

Cable Start-up Temp (˚C) 6A 10A 16A 20A 32A
GP-18 +10 26 42 68 84 90
  0 24 38 62 78 86
  -15 20 34 54 68 80


If you would like the experts at BN Thermic to select a gutter protection system for you, please send an email to  with details of your application and we will respond with detailed proposal.

GP_gutters diag 1

Cable selection for gutters

A single run of GP-18 self-regulating heating cable will protect gutters with widths up to 120mm.  For wider gutters add an additional run for every 120mm increase in width.  For example a 350mm wide gutter will require 3 runs of cable.

Cable selection for downpipes

For downpipes at the end of a gutter a single run of GP18 self-regulating cable will be required.  The cable should extend approximately 500mm below ground level.

For downpipes which interrupt a gutter, a loop of cable should be installed with the end of the loop extending approximately 500mm below ground level.

GP_downpipe diag2 1


THJ 01 1

THK termination kit should be used to prepare one end of the cable for electrical connection and to seal the far end

Electrical connections should be made in a THJ IP66 junction box

Spacer Kits

A GP-S spacer kit consists of five stainless steel spacers and 10 UV resistant cable ties.  The spacers are used to protect the heating cable as it passes over a sharp edge and to maintain the correct spacing when multiple cable runs are installed in a gutter.

GP_spacer kits


Control by means of FST2-EX (20A 230V) IP65 thermostat is recommended for economy.