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FlexHeat Heating Cable

Cost-effective cable kit for a variety of applications. 

Universal Underfloor Heating Cable

A flexible simple to fit heating system designed to provide energy-efficient floor warming or a full heating system as desired. This electric underfloor heating cable is particularly suited to small or intricate areas where heating mats can be more complicated to install.

The system's output is varied by altering the spacing of the heating cable, allowing 200W/m to be installed in conservatories and similar high heat loss areas. An additional benefit of this system is that it can be used beneath virtually any floor covering if covered with a levelling compound and installed with an output of no more than 160W/m2.

  • When installed at 200W/m2 this system is suitable for providing a full room heating system, even in high heat loss areas such as conservatories
  • Perfect for floor warming or room heating in standard rooms when installed at 160W/m2
  • Alter the heat output to match your individual requirements - outputs from 80W/m2 to 230W/m2  are possible
  • The compact FlexHeat range is designed for installers to be able to keep a small range of sizes in stock which can be mixed and matched to provide coverage for nearly any room
  • When used with Heat Mat's intelligent thermostat timers this heating cable provides a more energy-efficient and cost effective heating system than lower powered alternatives
  • Great value for money - can be installed onto thermal insulation boards to provide a faster reacting and more economic heating system
  • Significantly quicker to install than some alternative systems as there is no need to cover the entire heating cable with tape due to its high strength outer insulation

FlexHeat Cable converts electricity into heat with almost 100% efficiency, so the running costs of a system depend largely on the room’s insulation and the target temperature.

The better insulated a room is, the less expensive it will be to operate the underfloor heating system, with the largest benefit being obtained in installing thermal insulation boards directly beneath the cable.

When installing FlexHeat Cable at an output of 150W/sqm onto a well-insulated floor, we would expect the underfloor heating system to operate on average for less than 40% of the time to provide a total heating system. With electricity costs of 10 pence per kilowatt hour this would lead to running costs of around 0.6 pence per hour when the heating system is running.

Assumptions made for the above calculations:

  • The FlexHeat Cable has been installed at an output of 150W/sqm
  • The cable is installed on top of 10mm thermal insulation board, beneath standard ceramic tiles
  • 100% of the floor is covered with underfloor heating
  • The insulation in the property is up to the current Part L regulations
  • The price for electricity is 10p per kilowatt hour
  • The system is run via Heat Mat's Part L Compliant 4th Generation NGT thermostat, with the anticipatory setting enabled
  • The system is operating while the average ambient temperature is 10oC, and the system is heating the room on average for ten hours a day

Selecting the correct heating cables

To start with you will need to decide on the heat output of your heating system. For floor warming or room heating in well-insulated areas we suggest installing the cable at roughly 150W/m2, and for high heat loss areas, or for a faster reacting system, we recommend choosing a 200W/m2 output.

Once you have chosen your desired output you should measure your room to find the total floor area. You should then subtract from this figure any areas where kitchen or bathroom furniture will be placed, or where furniture without an air gap underneath it will be positioned. Once you have subtracted these areas you have your Free Floor Area (FFA). If you multiply the FFA by the Wattage output you have chosen you will have the total output of heating cable you require, and you should then choose the most suitable combination of heating cables, to provide you with the closest combined Wattage to your required output.

Combining multiple units

Undertile heating cables are designed to be laid together with other heating cables to ensure the perfect floor coverage. The cables are wired into the thermostat or junction box in parallel, and heating cables can be used to 'fill in the gaps' in a heating mat system, as long as they are laid at the same output as the mats.

Flexible and quick installation

Heat Mat electric undertile heating cables are incredibly simple to install, and in small or complicated areas can be significantly quicker to install than heating mats. The cable spacing can be altered to match your exact heat output requirements, and the system is fixed to the floor with the supplied high strength double-sided tape before tiling on top.

Sub-floor surfaces and insulation board

FlexHeat cables can be supplied with insulative primer which decreases the warm up time of the system. However, for the most energy-efficient system and fastest warm up time we recommend laying heating cables onto Heat Mat thermal insulation board. Heating cables can also be laid onto pre-primed concrete, tile or stone surfaces or suitably secured ply board.

Suitable for nearly any floor covering

If you are unsure of the final floor covering, the heating cables can be laid at an output of up to 160W/m2 and covered with flexible levelling compound. This allows nearly any floor covering to be laid on top including tiles, stone, carpet, laminate, solid wood, Karndean and vinyl.

Approved and guaranteed

Heat Mat’s electric underfloor heating cables are independently BEAB and Semko approved, manufactured in Denmark in our BEAB approved factory, and supplied with a Lifetime Warranty. They are also certified by Semko as having a very low EMC radiation, which is a result of their twin conductor design and 100% aluminium earth shield.

FlexHeat Heating Cable Specification

Product Code (with primer)

Product Code (without primer)Coverage in m2Wattage
FLX-PRI-0200 FLX-CAB-0200 1.0 to 1.5 200W
FLX-PRI-0300 FLX-CAB-0300 1.6 to 2.2 300W
FLX-PRI-0400 FLX-CAB-0400 2.3 to 3.0 400W
FLX-PRI-0600 FLX-CAB-0600 3.1 to 4.4 600W
FLX-PRI-0800 FLX-CAB-0800 4.5 to 5.9 800W
FLX-PRI-1000 FLX-CAB-1000 6.0 to 6.9 1000W
FLX-PRI-0600 x 2 FLX-CAB-0600 x 2 7.0 to 8.4 1200W
FLX-PRI-1400 FLX-CAB-1400 8.5 to 9.9 1400W
FLX-PRI-1600 FLX-CAB-1600 10.0 to 11.0 1600W

Technical Data

  • Supply Voltage: 230V +/-10
  • Output range: 200W - 1600W
  • Maximum Load: 15W/m
  • Range Coverage: 1.0m2-11.0m2
  • Coverage at 200W: 0.6m2-12.0m2
  • Maximum Cable Temperature: 90 °C
  • Approvals: CE Marked and BEAB system approved
  • Wire Thickness: 2.7mm to 3.2mm depending on Ohm Value
  • Cable Flexibility: Minimum allowable cable radius is 18mm
  • IP Rating: IPX7 as required by the 17th Edition IEE Wiring Regulations
  • Compliant with: Part L, 17th Edition IEE Wiring Regulations, EN 60335-1:1998, EN60335-2-17:1999, IEC60730


  • Thermal Conductor: 2 x resistance wire insulated with fluoropolymer (FEP 7Y) tested to 200°C
  • Coldtail lead: 2m double insulated cable
  • Outer Insulation: PVC (Y) tested to 90°C
  • Earth Protection: 100% aluminium earth shield
  • Reinforcement Materials: Fibreglass strands
  • Reinforcement Mesh: Fibreglass mesh
  • Fixing Material: Supplied with double-sided tape


Heating cables must always be controlled by a suitable electric underfloor heating thermostat with floor temperature limitation. Heat Mat thermostats are rated to 16 Amps, and if a system exceeds this loading a suitably rated contactor should be used. The circuit must be protected by a 30mA RCD and suitably rated fuse or circuit breaker.

  • Flexible cable - Ideal for use in small or complicated rooms
  • FlexHeat cable is available in kits with an insulative primer to prevent downward heat loss
  • The heat output can be altered throughout a room to match individual requirements - in front of doors or in 'cold corners'
  • Ideal for tiled floors, carpet, bonded-wood and vinyl surfaces, if first covered with a flexible levelling compound
  • Ultra-thin fluoropolymer insulated cable ensures minimal build height
  • Robust outer insulation - no requirement to cover the cable with tape before laying your floor covering
  • Advanced dual conductor cable design - only one connection lead
  • Supplied with a 10 Year Warranty
  • Independently BEAB and Semko approved
  • Made in Denmark

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