Newport Bathroom Centre 19-24 George St, Newport, NP20 1EN, Tel:01633 262629

Warmup Undertile Heating & Installation

Underfloor heating uses a radiant heat design to gently heat the room from the bottom up. The Warmup "Loose Wire System" is designed using a 3mm, ultra-thin, dual-core heating element. The small cross-section of the element allows it to be installed in a matter of hours without raising floor levels. There is no need to dig up the floor and no need to mix concrete. Simply fix the heating element to the subfloor, tile straight over and say goodbye to cold feet for good!

The Warmup Undertile Heater has been designed so that installation is quick and easy. However, as with all electrical underfloor heating systems, certain procedures must be followed. Ensure you have read all technical specifications and you are happy to fit Warmup Undertile Heating to your room. It is recommended that all electrical work is carried out by a qualified electrician. To install your Warmup underfloor heating system follow these five steps. Please note that this is a summary.  The Warmup Undertile Heating system is available from Newport Bathroom Centre so please telephone us on 01633 262629 for our latest brochures, prices and offers.



1. Smooth, clean and dry the subfloor
The surface must be smooth, dry and free from grease.

2. Paint the floor with Warmup Primer
You do not need to use primer if installing on an insulated tile back board. If fitting to a wooden floor, the floor must be fitted with tile backer board or plywood. If fitting to a solid floor the concrete must be completely dry.

3. Allow primer to dry The light green colour of the primer will change to a dark green once dry. Avoid traffic once primer is down.


1. Mark the heater position on the floor
Calculate in square meters the size of the area to be heated. Use the Sizing Guide (found in the back of the Installation Manual) to correctly fit your heating wire into the space provided.

2. Mark the start point
As close to the power supply as possible but no further than 2.5m from it.

3. Mark perimeter and spacing intervals
Mark all outer corners of the heated areas referring to the Sizing Guide. Join the corners to form a marked out perimeter. Mark the spacing intervals for the underfloor heating wire.

Remember: Plan the heater layout and installation so that any drilling after tiling will not damage the wiring.


1. Gently pull the black power supply cable from the box
After 3 meters, you will reach the point at which the power supply cable joins the heating wire. The joint should be taped to the floor at the start point

2. Layout the heating wire in parallel lines
Begin at the start point and in U shapes go to the furthest point.

3. Space and secure with fixing tape
Using the wire spacing markings as tape down points, secure the heating wire to the floor with adhesive tape.

4. Lay out balance of heating wire
In order to achieve even coverage of the balance of the area to be heated, you may at this stage need to adjust some of the wire spacing that you previously secured. The heating wires are spaced at least 50mm apart at all times and the heating wires never cross.

5. Tape down the entire heater
Once completed, tape down the entire length of the heating wire, positioning the tape centrally over the wire.

6. Fix power supply cables
If necessary, chisel out channels for power supply cables and the floor probe wire this will minimise the increased height. Fit the power supply cables into the channels and secure with fixing tape. Remove all debris and chippings from the floor.

Remember: Protect the heating wire with cardboard or hardboard between installation and tiling.


Follow the instructions supplied with your thermostat. Your underfloor heating system will not function without a correctly installed thermostat.


1. Check the heating wire is fully taped and secure.

2. Tile as normal, taking care not to damage or dislodge the heating wire.
If tiling with mosaic or similar tiles, it is advisable to cover the heating element with latex self-levelling compound before tiling. When using a notched trowel, gently comb the adhesive in straight lines in the same direction as the runs of the heating wire. DO NOT lift tiles once the adhesive is dry, as this will damage the heating wire.

3. Grout the floor as soon as possible as per the manufacturers instructions.
DO NOT switch on the heater until the tile adhesive is fully dried (minimum 7 days). Remember: Use ceramic tile adhesives and grouts suitable for use with underfloor heating.

Check the underfloor floor heater is working directly before commencing tiling.

Extra Warmup Information

Warmup provide further information on their products:

Undertile Brochure - 839 kb
Undertile Installation Manual - 241 kb
Warmup Video
Warmup Loose Wire Installation Video

We can supply what your bathroom needs from ceiling to floor and every bathroom accessory to fit in-between and we supply you with quality equipment from all the major bathroom accessory suppliers including: Acova, Newport Heated Towel Rails, Aurora, Be Modern, Bisque, Bristan, Cifial, Ferrara, Hatria, Heritage, HIB, Hudson Reed, Just Taps Plus, Marbex, Pegler, QX, Roper Rhodes, Sphinx, Tavistock, Utopia, Warm-Up & more....