Underfloor Heating: Frequently Asked Questions

Frequently Asked Questions for Underfloor Heating

Q: Can I Install The System Myself Or Do I Need An Expert?

A: All underfloor systems, whether it is cable, cable mat or carbon film, come with a full set of installation instructions, providing simple step by step instructions. Most systems can be installed on a DIY basis. But the final electrical connection should be made by a qualified electrician.

Q: Are electric underfloor heating systems designed to heat a room or just to keep a floor warm?

A: Electric underfloor heating systems are suitable for both purposes. Only in poorly insulated areas and in very cold conditions may supplementary heating be required, using insulation and a higher heat output system will reduce the need for this.

Q: Is electric underfloor heating expensive to run?

A: Electric underfloor heating can be the most cost effective heating method because the temperature of each room is individually controlled by a programmable thermostat. We also recommend laying insulation boards prior to laying your heating elements this will stop any heat escaping and give you the maximum effect of your electric underfloor heating system.

A 2.5m2 floor in a bathroom fitted with Ecomax insulated tile backer board would cost approximately 7p per day to run, this is based on the heating system being on twice a day for two hours each time, this assumes a 50% duty cycle once the floor has reached temperature and assumes a cost of 8p per kwh.

Q: Are There Any Special Wiring Requirements?

A: For most domestic size rooms the system can usually be connected to an existing household ring main circuit, wiring via a fused switch spur. For larger areas a single dedicated circuit from your consumer unit may be needed. The Thermostat will accept 15 amps, if the floor area produces more than this then the system must be wired through a contractor, to take the loading. All electrical work must be carried out by a qualified electrician who will be able to advise you on what is needed.

Q: How safe is an electric underfloor heating system?

A: Electric underfloor heating systems are a particularly safe method for heating a room. With an underfloor heating system the heat is spread over an entire floor area, rather than being concentrated in a relatively small area as is the case with today’s conventional radiators. This means that the temperature of the floor surface is much lower than the surface temperature of a radiator. For this reason underfloor heating systems can be used in places for example like “children’s nurseries” where conventional heating systems are not permitted.

Q: How long will it take to warm up?

A: This will vary depending on the sub floor and the insulation. The better the insulation the quicker it will heat up. On average 30 to 60 minutes on a wooden sub floor, but it may take several hours on and un-insulated concrete floor. However on concrete floors it will retain the heat in the concrete and therefore take much longer to cool down. Warm up times can be drastically reduced to as little as 15 - 20 minutes if using an insulated tile-backer board such as Ecomax.

Q: Will my floor get too hot?

A: The thermostats come supplied with a floor probe that will continuously monitor your floor temperature. The required temperature can be easily adjusted. Most of our customers like a floor temperature between 22 and 27°C.

Q: How do I decide between heating mats and cable kits?

A: Ecofloor underfloor heating mats are preferred to Ecoflex cable kits because they are quicker to install and, as the spacing of the cable on the mat is predetermined, they ensure an even distribution of heat. However as the mats have a 500mm width that cannot be reduced, this can prove to be difficult when installing in irregular shaped rooms or where there are a number of permanent fixtures that have to be worked around. In this instance cable kits are recommended as the more suitable option.


A: Yes, but it is common practice to locate the thermostat on an outside wall (typically on the landing or in the hall) with the floor probe running through the wall into the floor where the heating is installed.

Q: Do I need a thermostat?

A: Yes. The TH132AF will control the ambient air temperature and the floor probe will control the floors surface temperature. The TH132F will only control the floor temperature via the floor probe, ideal for bathrooms or areas where just the chill of the flooring is required to be removed. Both thermostats are fully programmable and will give you full 7 day control of optimum start and night set back facilities.

Q: Do I need to install insulation?

A: When using Ecofilm under laminate, engineered wood or timber floors our Ecomax-Lite thermal insulation boards should always be used. It not only provides thermal insulation, reducing running costs, but acts as a method of sound deadening and forms a suitable non-abrasive surface on which the Ecofilm can sit.

Ecofloor underfloor heating mats and Ecoflex cable kit systems for tiled floors work ok without insulation. However Ecomax insulation boards are recommended for Insulation when installing Ecofloor or Ecoflex products, these are available in 600mm wide x 1250mm long and 6mm or 10mm thick these cover a surface area of 0.75m2 per board and will provide you with optimum efficiency from your heating system.

Q: Can I use more than one heating mat in one room?

A: It is common practice to use more than one Ecofloor mat to fill a space. Usually the mats are connected in parallel and the group is controlled by a single thermostat. However care must be taken to ensure that the combined load does not exceed the switching capacity of the thermostat. The switching capacity of the divine underfloor heating systems is 16A or 3.6kW.



Q: Are Divine heat products covered by a guarantee?

A: Of course they are! All our underfloor heating products carry a 10 year warranty while thermostats carry a one year warranty.

Q: Is underfloor heating suitable for heating a conservatory?

A: Electric underfloor heating systems are ideal for conservatories. When using electric underfloor heating in this sort of area we would strongly recommend the use of the 200W/m2 system or the 160W/m2 for wooden or laminate floors. We would also highly recommend using a suitable insulation board like Ecomax thermal tile backer board or Ecomax-light thermal insulation board.

Q: Can cables or mats be cut to length?

A: Electric underfloor heating cables must never be cut. Ecofloor mats consist of a cable fixed to a nylon web. Whilst the cable must not be cut you can cut the web at any point to allow the mat to be laid out to suit the shape of the room.

Q: Can I return an underfloor heating system to you if I change my mind?

A: Yes you can. As long as you return the product in the same condition and in no way damaged you can return items to us for refund within 7 days of purchase please see our terms & conditions.


A: If you realise that you have purchased the wrong size system before unpacking, you can simply return the item to us within 7 days of purchase and we will find a suitable heating option to fit to your requirements.

Q: Do I need special tools?

A: To install a Ecofloor heating mat or Ecoflex cable kit under ceramic tiles you should use a plastic serrated trowel rather than a steel trowel. This will reduce the chance of damaging the heating cable. Plastic trowels are readily available from any local tile shop.

For all installations the final electrical connections MUST be made by a qualified electrician in accordance with the current wiring regulations.


A: Yes. For ceramic, porcelain, stone etc, a fast setting flexible tile adhesive and grout will be required. The special polymers added to flexible adhesives will make allowances for any tile floor movements through heat expansion and contraction.

Q: What Is The Advantage Of A Higher Wattage System?

A: The 200W/m2 Ecofloor mats and Ecoflex cable kits and the 160W/m2 Ecofilm are ideal for high heat loss areas, such as conservatories etc, where you will need higher output than the standard. Running costs are not affected as you will reach the required temperature faster and from there the thermostat will accurately regulate the power consumption to meet the chosen temperature.

Q: How long do I have to wait before using my underfloor heating system?

A: Ecofilm for wooden or laminate floors can be switched on 3-5 days after installation is complete allowing for your floor to fully acclimatise to its new surroundings and, if relevant for any adhesive to fully cure. Ecofloor underfloor heating mats and Ecoflex cable systems for tiled floors must only be switched on once the adhesive or compound in which they sit is completely dry. Typically this will take between 2-3 weeks, please check with the adhesive or compound suppliers for this information, this info should also be available on most adhesive packaging.

Q: What happens if I damage my underfloor heating during or after the floor surface has been laid?

A: With laminate (or similar) floor, the solution is relatively simple as the floor can be lifted and an individual heating film can be easily replaced.

With ceramic and stone floors, a tile or group of tiles will need to be lifted to expose the damaged cable. Divine underfloor heating can provide a repair kit to allow the cable to be repaired before you relay your chosen surface.

As you can imagine this procedure can be quite extensive so please make every effort not to damage the heating element during or after installation.

Q: What makes Divine heat better than other Suppliers I have seen online?

A: Here at divine heat our friendly staff are fully experienced and trained to offer you competent and knowledgeable help and advice. We strive to ensure efficient customer service and strong product knowledge. We also pride ourselves in knowing we supply some of the best products available today direct to our customers at fantastic online prices.