How to install a Electric Underfloor Heating Cable

 What's In The Kit

- The heating cable

- A 1.5 m long flexible Conduit

- A 2.5 m long flexible Conduit terminated at one end with a rubber Stopper

- Temperature controller & Floor Sensor (IF ORDERED)

What's Needed

- Tape

-Glue Gun

- Ohmmeter (multimeter)

- Tools for cutting chases in walls and floors


The insulation's resistance for the heating cable, as measured with a tool of the rated voltage 1000 V (e.g. megaohmmeter), should not be below 10 Ohms.

The resistance test for the mat should also be done after the insulation's resistance test has been done. The total resistance will be on the label connected to the cold tail.

Enter the results into the Warranty Card.

When the floor has been finished, repeat the measurements and compare the results to ensure that the mat has not been damaged while laying the floor.

The Underfloor Heating Cable should be tested at these points;

  • After Unboxing and before installing
  • After installing
  • And after the adhesive has been laid or the floor finish


  1. Make sure the sub-floor is dry, clean and dust free and suitable for tiling. If using a wooden sub-floor, ensure it is stable, if not reinforce it to prevent flexing and dislodging. Do not install the cable directly onto a bitumen base.
  2. Prime the floor using an acrylic bond making sure to cover the whole area of screed or insulation. Once the primer is applied, leave it to dry before laying the Elektra Undertile Cable. (Usually 1-2 Hours)
  3. If using Ekoboard or any other XPS premium insulation boards they should be staggered as accordance to the manufactures instructions. Make sure the boards are secured to the floor with a strong adhesive, if installing onto a wooden surface make sure boards are fixed manually.
  4. Now we are nearly ready to start laying our Elektra Undertile Heating cable, but first we need to refer to the testing section earlier in the guide. We need to test the cable after unboxing to make sure none of the cable has been damaged during transit.
  5. Study the floor plan carefully and select the best possible place to start the circuit and where to place the thermostat and floor sensor. This is the most important step, as any mistakes can be crucial after fitting.
  6. Now start to install the heating cable from the location of the thermostat, roll out the cable and secure to the surface by taping or gluing the cable. The cable should be 50-100mm away from the wall perimeter.
  7. When you reach the end of the room, at no time should you cut the cable.
  8. Once laid, check the cables resistance and insulation values are consistent with pre-insulated values and record these on the guarantee certificate.
  9. Depending on the type of cable the cold tail should be the black lead this will either be a solid earth cable or a earth braided wrapped around internal cores. This needs to be upbraided by using a screwdriver and pulling down the braid into separate strands. At this point the earth can now be connected to the incoming supply by using the earth terminal in the black box.
  10. To monitor the temperature of the heating cable we need to install a floor sensor, to do this cut a section out of the insulation wide enough for the black conduit to fit in. The floor sensor must go in between two runs of the cable allowing the best possible reading. Place the floor sensor inside the conduit and then place into the hole cut out. If you need to shorten the floor sensor only cut the end with open wires, do not cut the end which contains the plastic sensor.

  11. Now we need to refer back to the testing again to make our final test on the cable, check the resistance using the multimeter and then the insulation resistance as well.
  12. If possible cover the cables with a thin layer of suitable latex based levelling compound 5-6mm. This will help protect the heating mat when laying the floor finish a levelling compound is not mandatory but is advised.
  13. Tile the floor using a flexible tile adhesive and grout as per industry standards and manufactures conditions. Once the floor finish has been applied slowly turn the heating on and start to increase the temperature over a few days. After a few days you can then set your desired settings.



Never cut the heating cables.

Never shorten the cables, only cold tails may be made shorter, if necessary.

Never attempt to squash the cold tail.

Never attempt the self-repairs of the heating cables. If the heating cables are damaged, please contact an ELEKTRA authorised installer.

Never expose the canbles to the excessive stretching, stress or hit them with sharp tools.

Never attempt to lay the cable if the ambient temperature drops below -5°C.

Never install the cable under fixed furniture is planned (e.g. legless floor-level wardrobes, kitchen units, baths).

Never use installation materials other than specified in the installation manual.

Never use nails or screws of any kind for installation of the cables.

Always install the heating cable according to the installation manual.

Electrical connection of the cable must be performed by a certified electrician.

The minimum distance between the heating cable and other heat sources (e.g. hot water pipes) should always exceed 25 mm.

The electric heating cable must be connected by a qualified electrician and requires a mains voltage of 230/240v

When laying the Elektra Undertile Heating cable, under no circumstances the heating cable be cut or cross at any point.

The joint between the heating cable and cold tail must be located under the floor.