Question 1

What size mirror demister do I need?

Accepted Answer

We have a useful calculator on our website to assist with working out the pad size you will need. the calculator takes your mirror size and deducts a border of approximately 50mm on all sides. The calculator can be found here https://theheatingpartnership.co.uk/pages/mirror-demister-calculator

Question 2

How do I attach the demister to the mirror?

Accepted Answer

The mirror should be placed face down on a suitable flat surface, and the back of the mirror should be cleaned of any dust or grease. You should remove the protective backing from the mirror heater and, placing it centrally in your mirror, you should place one edge of the heater onto the mirror and firmly press it onto the back of the mirror. You should then work outwards from that point sticking the whole heated pad onto the back of the mirror while carefully smoothing away any air bubbles. Do not worry if there are white patches that form beneath the film as you fit it, this is due to a de-lamination between the internal layers of the pad and does not affect the heater's performance.

Question 3

How do connect my mirror demister?

Accepted Answer

The final electrical connections must be made by a suitably qualified electrician and should comply with the latest wiring regulations. Usually, the Demista pad would be powered through the lighting circuit so that it energises whenever the bathroom light is activated, although the heater can be wired through a separate switch or on a timer if preferred. Any circuit supplying a 230V mirror demister must be protected by a 30mA RCD or equivalent and must also be protected by a suitably rated MCB. The power rating of all Demista brand mirror demisters is 200W/sqm.

Question 4

My mirror is larger than your biggest pad. How do I install multiple pads on a single mirror?

Accepted Answer

For large or unusually shaped mirrors multiple heaters can be fitted to a single mirror, and these must be powered in parallel; if fitting low-Voltage pads they can be run off a single transformer if it is suitably rated for the combined load. When fitting multiple pads together on a single mirror it is important that they do not overlap, and we recommend an unheated area at least 10mm wide between the heaters.

Question 5

How long is the supply cable for the demister pads?

Accepted Answer

The mirror defoggers are supplied with a 1.0m double-insulated supply cable which cannot be lengthened or replaced. If this supply cable is not long enough for your requirements a suitable junction box should be used to bring the power to the mirror heater.

Question 6

Do I earth the demister pad?

Accepted Answer

Once the mirror heater has been installed it must not be accessible or in an area where it could be physically damaged. All exposed metal parts surrounding the mirror (for example if the mirror has a metal frame) must be earthed to comply with the current wiring regulations. Mirrors that have a foil backing or metallic covering must be earthed using a grounding pad to remove the risk of a capacitance build up.

Question 7

How do I fix the mirror to the wall?

Accepted Answer

The wall area where you are going to fit your mirror should be firm, flat, and dry, and the mirror must have space at its edges to allow it to expand slightly as it is heated. If using a mirror adhesive this must be solvent and acrylic free, and we recommend adhering to the adhesive manufacturer�s instructions. It is perfectly acceptable to use mirror adhesive on the back of the heating pad. If the mirror is being fitted to the wall with screws, the screw holes must have bevelled edges, and the screws must not be over tightened as this risks cracking the mirror. The screws must be isolated from the mirror with a material such as cork or rubber which will allow slight expansion.

Question 8

How long is the warranty on your demister pads?

Accepted Answer

Demista products have an industry-leading 10 Year Warranty

Question 9

How do I install a mirror demister?

Accepted Answer

We have a useful video and webpage that should answer your questions, if not please come back to me with any questions. Check this link for more information

Question 10

How does the demister pad stick to the mirror?

Accepted Answer

Mirror demisters include a self-adhesive backing to firmly attach themselves to your mirror.

Question 11

Can mirror demisters overlap on the back of the mirror?

Accepted Answer

No, the mirror demisters should not overlap. There should be a 10mm gap between mirror demister pads if multiple pads are being used to heat a single mirror.

Question 12

What is a common mistake when planning the layout for EUFH?

Accepted Answer

One common mistake is failing to plan the layout properly. This can lead to uneven heat distribution or wasted energy if mats or cables are placed under fixed furniture like kitchen islands or cabinets, or if thermostat placement is overlooked.

Question 13

How can you avoid layout planning mistakes in EUFH?

Accepted Answer

To avoid layout issues, create a detailed plan showing the exact position of heating mats or cables, ensure thermostats and sensors are placed correctly away from heat sources, and leave fitting space around the room edges for thermal expansion.

Question 14

Why are insulation boards important for EUFH?

Accepted Answer

Insulation boards are crucial because they prevent heat from escaping into the subfloor, making the heating system more energy-efficient. Without insulation, more energy is required to heat the space, increasing running costs.

Question 15

How do you choose the right insulation boards for EUFH?

Accepted Answer

Select high-quality insulation boards designed for underfloor heating. Match the insulation type to the subfloor�for concrete floors, use thicker boards; for timber floors, thinner boards may suffice.

Question 16

Is it important to install the floor sensor?

Accepted Answer

If a floor sensor is not installed there is not a reliable way to monitor the temperature of the floor. This can lead to the floor overheating and depending on the floor finish, can damage the floor. Also, incorrectly placed floor sensors can result in inaccurate temperature readings, which may cause the system to overheat or underheat, leading to inefficiency or potential damage. If you are unsure, please contact us for advice.

Question 17

How can you correctly place floor sensors for EUFH?

Accepted Answer

Place the floor sensor equidistant between heating cables to avoid misleadingly high readings. Install it in a conduit tube for easy replacement and keep it away from external heat sources like hot water pipes or direct sunlight.

Question 18

What happens if heating cables overlap or cross?

Accepted Answer

Overlapping or crossing heating cables creates hot spots that can cause the system to overheat, leading to potential cable failure or even fire hazards. It is essential when the heating cables are installed that they do not cross, they must stay at least 40mm away from each other.

Question 19

What is the correct spacing of heating cables?

Accepted Answer

On the heating mats the cables are pre-spaced to give the correct output and an even heat distribution. If you are installing loose cables, then the spacings will depend on the output per m² that is required. Please phone us and we can give you advice on the cable spacings required.

Question 20

What are cold-tail connections?

Accepted Answer

Cold-tail connections are critical points where the heating system connects to electrical power. If these are installed incorrectly or left exposed, it can lead to dangerous overheating or system failures.

Question 21

How should cold-tail connections be installed?

Accepted Answer

Cold-tail connections should be fully encapsulated in a cementitious medium, such as tile adhesive or screed, to protect them from damage. Avoid leaving them exposed or taping over them, as this can trap heat and cause overheating. They should not be in the wall, behind or chased into the skirting - they must be in the floor beneath cement, tile adhesive or levelling compound.

Question 22

Why do I need to test the underfloor heating system?

Accepted Answer

Testing the system before laying the flooring is essential to identify any issues with cables, sensors, or connections. Fixing problems after the floor is installed is much more challenging and expensive. We recommend testing for continuity and recording the ohms reading, check this against the value that is printed on the box or on the product. The mats and cables should be tested firstly whilst in the box, then during the installation, before any levelling compound is laid and then lastly before the floor finish is installed.

Question 23

What tests should be conducted during EUFH installation?

Accepted Answer

During installation, perform continuity tests with a digital multimeter, insulation resistance tests to check for cable leakage, and a full system test to ensure everything works correctly before covering the system.

Question 24

What are permanent changes in EUFH installation?

Accepted Answer

Permanent changes, like laying tiles or pouring levelling compound, make it difficult to fix mistakes or problems. Once these steps are completed, any errors become costly and time-consuming to correct.

Question 25

How can you ensure a successful EUFH installation?

Accepted Answer

Double-check every aspect of the installation, document the process with photos or videos, and consult professionals if you have any doubts. These steps will help avoid costly errors.

Question 26

What issues arise from using the wrong adhesive or levelling compound?

Accepted Answer

Using inappropriate adhesives or levelling compounds can damage the heating system. Inflexible materials can crack under heating cycles, causing damage to cables and reducing efficiency.

Question 27

What is the correct adhesive or levelling compound to use?

Accepted Answer

Choose flexible adhesives or levelling compounds specifically designed for underfloor heating. These materials can expand and contract with heating cycles without causing damage. Always follow manufacturer guidelines.

Question 28

Why is the dot-and-dab tiling technique unsuitable for EUFH?

Accepted Answer

The dot-and-dab method creates air pockets under tiles, leading to uneven heating and hot spots. This can cause overheating and potentially damage the cables.

Question 29

What tiling method is recommended for EUFH?

Accepted Answer

Use a solid bed of tile adhesive, ensuring that cables are fully encapsulated. Apply the adhesive evenly with a notched trowel and press tiles firmly to eliminate any gaps.

Question 30

Can i use the underfloor heating to cure the concrete?

Accepted Answer

Turning on the system before the adhesive or screed has fully cured can cause cracking and compromise the installation. Using the system to speed up drying is not recommended.

Question 31

How long should you wait before turning on the EUFH system?

Accepted Answer

Refer to the manufacturer�s guidelines for curing times, which may range from several days to weeks depending on the materials used and environmental conditions.

Question 32

What are the risks of ignoring manufacturer instructions for EUFH?

Accepted Answer

Ignoring manufacturer instructions can lead to unsafe or ineffective installations, void product warranties, and increase the likelihood of system failures.

Question 33

How can you avoid issues with manufacturer instructions?

Accepted Answer

Carefully read and follow the instructions provided with the system. Ensure all installers have access to the guide, and consult the manufacturer or professionals if needed.

Question 34

What is the recommended tog rating for carpet and underlay when using underfloor heating?

Accepted Answer

The combined tog rating of the carpet and underlay should not exceed 2.5. A higher tog rating acts as an insulator, blocking effective heat transfer.

Question 35

Can underfloor heating be used with carpet?

Accepted Answer

Yes, underfloor heating is compatible with carpet, provided that the tog rating is within acceptable limits and the carpet and underlay are chosen carefully. The maximum combined tog rating of the carpet and underlay should not exceed 2.5. we also recommend the heating system is encapsulated with a 12mm layer of flexible floor levelling compound.

Question 36

What are the benefits of underfloor heating under carpet?

Accepted Answer

Underfloor heating under carpet provides a soft, warm surface, reduces noise by absorbing sound, and offers insulating properties that help retain heat, improving energy efficiency.

Question 37

What types of carpet should be avoided with underfloor heating?

Accepted Answer

Avoid high-pile or shag carpets with thick fibres, as they act as insulators and reduce heating efficiency. Rubber-backed carpets should also be avoided as they can trap heat and potentially cause mould.

Question 38

What type of carpet is recommended for underfloor heating?

Accepted Answer

Carpets with a tog rating below 2.5 and a hessian backing are recommended. These ensure better heat transfer and avoid issues like heat trapping or mould.

Question 39

What is the ideal underlay for underfloor heating under carpet?

Accepted Answer

The best underlay for underfloor heating has a low tog rating, preferably below 1.0. It should allow efficient heat conduction while providing light insulation.

Question 40

Which underfloor heating systems work best with carpet?

Accepted Answer

A 160W/m� or 150W/m� heating mat or cable encapsulated in a levelling compound works best for consistent and controllable warmth under carpet.

Question 41

Is underfloor heating under carpet safe?

Accepted Answer

Yes, underfloor heating under carpet is safe when manufacturer guidelines are followed. The floor temperature should not exceed 27�C, and installation should avoid flat-bottomed furniture directly above the heating system.

Question 42

How do you install electric underfloor heating under carpet?

Accepted Answer

To install, ensure the subfloor is solid and level. Lay insulation boards, followed by heating mats or cables spaced for even heat output. Cover with flexible cement-based levelling compound, then lay the overlay and carpet.

Question 43

What are the advantages of pairing underfloor heating with carpet?

Accepted Answer

This combination provides luxurious comfort, energy efficiency, and a cosy environment. Proper choices in carpet, underlay, and heating system ensure optimal performance without compromising style.

Question 44

Is electric underfloor heating too expensive to install?

Accepted Answer

No, advancements in technology have reduced installation costs. Pre-assembled heating mats make DIY installation feasible for small spaces, and it's less expensive than water-based systems.

Question 45

Is electric underfloor heating expensive to run?

Accepted Answer

No, it's designed to be energy-efficient, providing even heat distribution and maintaining consistent temperatures. Pairing it with smart controls or renewable energy sources can further reduce costs.

Question 46

Does underfloor heating overheat and damage floors?

Accepted Answer

No, modern systems have temperature controls that prevent overheating. By following manufacturer guidelines, underfloor heating is safe for wood, laminate, tile, and other flooring types.

Question 47

Is underfloor heating only suitable for new builds?

Accepted Answer

No, electric underfloor heating is highly adaptable and ideal for retrofitting. Slimline mats can be installed without significantly raising floor levels, making it a practical option for older homes.

Question 48

Is underfloor heating complicated to install?

Accepted Answer

Not necessarily. Pre-assembled mats allow for straightforward installation in small areas, and while professional help may be needed for electrical connections, the process is less invasive than water-based systems.

Question 49

Does underfloor heating provide enough heat?

Accepted Answer

Yes, it provides consistent and sufficient warmth if properly designed and installed. It works best in well-insulated spaces and can serve as a primary heat source in many cases.

Question 50

Is electric underfloor heating safe?

Accepted Answer

Yes, modern systems undergo rigorous testing and include safety features such as insulation and RCDs, ensuring safe operation even in wet environments like bathrooms.

Question 51

Does underfloor heating take too long to heat up?

Accepted Answer

While it can take longer to warm up than radiators, programmable thermostats allow users to preheat rooms, providing consistent warmth without noticeable delays.

Question 52

Is electric underfloor heating environmentally friendly?

Accepted Answer

Yes, it operates efficiently at lower temperatures and can integrate with renewable energy sources, making it a sustainable choice for reducing energy consumption and carbon footprint.

Question 53

What is electric underfloor heating (EUFH)?

Accepted Answer

Electric underfloor heating is a system that uses electric heating elements installed beneath the floor to evenly distribute heat in a room, controlled by a thermostat for customised temperature management.

Question 54

What are the benefits of electric underfloor heating?

Accepted Answer

Key benefits include energy efficiency, space-saving design, enhanced comfort with even heat distribution, easy installation, and low maintenance.

Question 55

How does electric underfloor heating improve energy efficiency?

Accepted Answer

By spreading warmth evenly across a room, EUFH maintains comfortable temperatures while using less energy, potentially reducing energy bills.

Question 56

What types of rooms benefit most from electric underfloor heating?

Accepted Answer

Bathrooms, kitchens, and other small-to-medium-sized spaces benefit greatly, especially where consistent, targeted heating is desired.

Question 57

What types of electric underfloor heating systems are available?

Accepted Answer

There are electric heating mats for regularly shaped rooms and loose wire systems for larger or irregularly shaped areas, offering flexibility in installation.

Question 58

Is electric underfloor heating compatible with all flooring types?

Accepted Answer

Yes, it works well with tiles, stone, laminate, and some carpets. However, it's important to ensure the flooring material is suitable for underfloor heating to maximise efficiency.

Question 59

How do you install electric underfloor heating?

Accepted Answer

The process involves preparing the subfloor, installing heating mats or cables, connecting a thermostat, and then laying the flooring. A clean, level subfloor and adherence to manufacturer instructions are essential. It is best to follow the manufacturers instructions and call us if you need any advice. If you are installing any floor finish that is not tiles or stone, it is important that the heating mat or cable is covered with levelling compound and our recommended thickness is 12mm.

Question 60

Can electric underfloor heating be used in any room?

Accepted Answer

Yes, EUFH is versatile and suitable for virtually any room, including bathrooms, kitchens, living rooms, and conservatories.

Question 61

What are the maintenance requirements for electric underfloor heating?

Accepted Answer

EUFH systems are virtually maintenance-free. Once installed, they require no regular servicing and are protected from wear and tear, ensuring long-lasting performance.

Question 62

Is electric underfloor heating a good option for renovations?

Accepted Answer

Yes, it's an excellent choice for renovations due to its easy installation, compatibility with various flooring types, and suitability for retrofitting without significant structural changes.

Question 63

What is included in an electric underfloor heating mat?

Accepted Answer

The heating mat consists of a heating cable embedded in a mesh with double-sided tape. It is 0.5m wide and comes in power ratings of 160 and 200W/m� at 230 V.

Question 64

What should be considered before starting the installation of electric underfloor heating?

Accepted Answer

Key considerations include ensuring electrical connections are made by a qualified electrician, calculating the required wattage per square metre, and planning the heated area to avoid placing mats under fixed units or furniture.

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