Underfloor Heating FAQ

How do I work out the Mat size or Cable length?
What are the facts about the running costs of electric underfloor heating?
Are your systems easy to install?
Will the floor get too hot?
Can underfloor heating be the only heat source?
Is it possible to vary the temperature?
Does it take a long time to warm up?
Do you provide a warranty with your products?
How thick is the under-tile cable/cable mats?
What about the thickness of the carbon system?

How do I work out the Mat size or Cable length?

Outline the area on the floor to mark the border of the area you want to warm, if you prefer measure the full room and then deduct the space taken up by the items that occupy floor space e.g. bath, shower, cabinets, toilet etc.

You will need to decide whether you want to lay a cable mat or a cable kit. NOTE: Remember, the rooms with awkward shapes those with baths, showers and cabinets, those which are small or odd shapes are ideal for cable kits.

Conservatories tend to be of similar shape and often do not have odd corners, nooks or crannies; in these cases a mat usually suites. NB: Our 200-watt mat is ideal for conservatories.

This will give you a good idea of the size of mat or cable you will need. If you decide you need a single cable kit, full details of how to calculate the cable spacing on the floor are provided - it's quite straightforward.

What are the facts about the running costs of electric under floor heating?

This is the most common question we get and the simple answer is, that the running costs are determined by many different factors so it is difficult to generalise.

However in most cases the running costs should not be a negative factor, especially in new homes, apartments and conservatories with insulated floors.

When the systems are used in a well-insulated building (in line with current building regulations) the running costs are usually very low, the thermostatic control in each room/zone means that you only use just enough energy to maintain your desired room temperature. Based on the default thermostat settings, a 1kw system will cost approximately £0.40 a day, based on an average house with an average level of insulation.

Floor Heating Systems have supplied sole source electric floor heating systems to much larger homes including barn conversions of up to 300sqm. Electric floor heating stands out as an excellent choice, especially in areas where there is no mains gas supply and the options are electric, oil, or calor gas. Electric floor heating is usually much cheaper to install than 'wet' systems and in some of the properties we supplied, the cost was less than half that of an equivalent 'wet' system.

Electric underfloor heating is also more efficient than radiators and other convected heat and requires no maintenance or servicing and 100% of the electrical energy is turned into heat energy , rather than being lost as exhaust gases as is the case with many gas central heating systems.

In our experience, the only time electric underfloor heating would be considered 'expensive' to run is when it is installed as a heating system in a poorly insulted home, with little or no floor insulation. Our advice for such situations is always therefore to spend that little bit extra on insulation and you will enjoy the benefits of cheaper heating bills for many years to come!

Are your systems easy to install?

See our installation pages under each system type - our systems are designed to be laid by anyone with basic DIY skills, but all electrical connections must be carried out by a suitably qualified electrician and in accordance with current regulations.

Will the floor get too hot?

Our systems are designed so that the floor surface will feel comfortably warm , but will never get too hot to walk on! The thermostat regulates the floor temperature by turning the system off when the floor gets to the required temperature, then back on as the floor begins to cool - thus keeping a constant temperature. It does this up to 3 times per minute for optimum control and maximum energy efficiency.

Can under floor heating be the only heat source?

In the vast majority of cases the answer will be yes, especially in new, well-insulated properties. The exceptions being old properties with little or no insulation, where you have limited floor space available, such as a small galley kitchen, or a small bathroom. In such cases if may be physically impossible to get enough heat output into a small confined space. If you wish to install a primary heating system in an old poorly insulated property, please contact us for advice.

Is it possible to vary the temperature?

Yes it can - The FH-01 thermostat controller allows the user full control of the heating system, including the 'occupied' temperature, the 'unoccupied' temperature and the times of operation using a 7-day/24 hr clock control.

Does it take a long time to warm up?

How long it takes to heat the floor will vary, depending on your sub-floor and its insulation. Generally the better the insulation the quicker it will heat up, 30 minutes to an hour on a wooden floor, but it will take longer on an un-insulated concrete floor. However, on concrete floors it will also retain the heat in the concrete and therefore take longer to cool down. The carbon film system is supplied with a thin insulation layer so warm up times will be no more than an hour on any sub-floor. However with tiles, if you lay the cables/cable mats onto un-insulated concrete, it can take several hours to heat up. We therefore recommend that you try to use Varme insulated tile-backer boards wherever possible when installing on an un-insulated concrete floor.

Do you provide a warranty with your products?

Yes all cables are backed by a manufacturers lifetime guarantee! The thermostat is guaranteed for five years from date of purchase.

How thick is the under-tile cable/cable mats?

The cables are just 3mm thick and include a built in return so they only need to be connected from one end.

What about the thickness of the carbon system?

The carbon film itself is less than half a millimetre thick and when combined with our 6mm 'Depron' insulating underlay below a wood floor, the total combined thickness of the complete system will raise your floor level by just 6.5mm.

(Note in a conservatory or on an un-insulated floor, we recommend a double layer of Depron making the increase in floor height 12.5mm)