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Underfloor heating guide

How does underfloor heating work?

With underfloor heating systems, your floor works like a radiator. UFH heats the room from the ground up, through a series of either pipes (warm water underfloor heating) or cables (electric underfloor heating) embedded in the floor.

There are many different types of underfloor heating – for example, thin retrofit underfloor heating for renovations.

If you’re considering underfloor heating in a new build or renovation project, our Technical Account Manager Rachel Roberts, who has over 17 years’ experience with underfloor heating at Nu-Heat, is here to explain.

This video answers the most commonly asked questions we hear, covering:

Read on for more FAQs, or jump to an underfloor heating guide section:

Jump to an underfloor heating FAQ

What are the benefits of underfloor heating?

  • Comfort levels: Warm water underfloor heating gives a more comfortable warmth than radiators. It feels natural, as it is similar to the way you are warmed by the sun. Where radiators heat the air by convection, drawing cold air across the floor and up to the ceiling, underfloor heating produces radiant warmth. The entire floor is heated so warmth is released evenly – no cold spots, stuffiness or draughts. You also get a lovely warm floor.
  • Low running costs: Once installed, underfloor heating is very energy efficient – around 25% more efficient than radiators. It uses lower temperatures and covers a much larger surface area of the room. If installed correctly, underfloor heating can help you save energy and save you money on monthly bills.
  • Design freedom: Underfloor heating frees up wall and floor space, giving greater interior design freedom. UFH systems are invisible, as they’re hidden below the floor, making them ideal for open plan living. Browse our case studies to see how real homeowners have used underfloor heating to transform their property.
  • Safety and health: The gentle heat and low humidity creates a kinder environment for furniture and the circulation of dust and mites is reduced, making the air cleaner and less allergenic. Underfloor heating is ideal for allergy sufferers, and also the elderly and children as there are no exposed hot or sharp surfaces.

How much does underfloor heating cost to install and run?

You may now know how underfloor heating works, but can it actually save you money in your monthly bills?

Warm water underfloor heating is really efficient – around 25% more efficient than radiators when paired with a modern condensing boiler, and up to 40% more efficient when running from a heat pump. Because of this, running costs are often lower than a traditional radiator system, and around a third of the cost of an equivalent electric UFH system.

When you buy underfloor heating from Nu-Heat, you get a lifetime of specialist support as standard from our award-winning customer service team. Our designs and systems are backed by Professional Indemnity Insurance. We offer up to 50 years warranty on key components, such as underfloor heating tubes, heat pump cylinders and manifolds.

Underfloor heating upstairs

Is my home suitable for an underfloor heating system?

Whatever the age, size or construction of your property, chances are it’s suitable for underfloor heating. Whether you’re building an extension, a new build, or renovating your existing home, we will design your UFH to be a perfect fit.

Nu-Heat’s in-house design software uses room-by-room heat-loss calculations to create the ideal, energy efficient system.

We look at the age and construction of your property; your home’s insulation and glazing levels; your location and orientation of your property; your chosen floor coverings; and how you use the different areas of your home.

The more energy efficient we design your underfloor heating system to be, the less the cost of UFH and monthly bills.

Underfloor heating new build

All new UK properties are built to strict guidelines on insulation and air tightness – key requirements for efficient underfloor heating. The system can be used in older properties as long as levels of insulation are enhanced as much as possible in line with current Building Regulations. Where this is not possible other upgrades, such as double-glazing, will help.

In a listed building where such improvements are impractical, UFH can still be installed but may require a higher flow temperature and closer tube spacing than in a well-insulated property. We provide specific information on expected heat outputs of every system and give a clear indication of any areas that may experience a shortfall on the very coldest days.

If we believe that the property is unsuitable for underfloor heating, we will always tell you so.

How is underfloor heating installed – do I need to dig up my floor?

No! For new builds and extensions, fitting the pipework into a layer of screed in the new floor as it is laid is a popular choice. We can help you with the underfloor heating installation process and finding a supplier.

All of our UFH systems have been designed with a simple installation in mind. With over 60 different types of underfloor heating, tube layout drawings, clear installation manuals and technical support, installing a Nu-Heat UFH system is easy.

Here’s what happens during a screed underfloor heating installation in a new build or extension.

Underfloor heating can also be fitted on top of your existing floor, and low-profile systems will minimise any disruption to fixtures and fittings. For home renovations, where you’re retrofitting underfloor heating in an existing house, thin and low profile UFH systems are ideal. Here’s what happens during underfloor heating installation in a renovation.

Nu-Heat’s LoPro®10 can be laid directly over the existing floor, adding as little as 15mm total height build up. Most homes are suitable for UFH, some of which are ready for your floor coverings to be fitted immediately.

Installing underfloor heating is a reasonably straightforward procedure, but it takes a certain amount of concentration to get it right. Nu-Heat supplies clear, fully illustrated installation manuals to help. Free technical advice is available by telephone or email during office hours from experienced underfloor heating experts.

Which floor coverings work best with underfloor heating?

Stone and ceramic

Hard flooring is the most efficient type of floor covering for use with underfloor heating. Stone, marble, polished screed or ceramic tiles are the most thermally conductive floor coverings, allowing the energy to transfer quickly to the surface. Flagstones take longer to reach the right temperature, but the heat emitted will be the same as with thinner stone.

Timber and engineered wood

Engineered timber flooring is the best wooden floor option for use with UFH because it performs well with fluctuating temperatures. Solid hardwoods and softwoods also transfer heat well, but it is essential to get the right thickness of the wood. Parquet can also be used as long as it is continuously glued to the screed or timber deck for good heat transfer.

Engineered boards are more stable than solid wood boards, but the lower operating temperature of underfloor heating means that most solid timbers can be used successfully, although these must be well-seasoned or kiln dried.

It is important to remember the ‘rug effect’! If you put a rug on a wooden floor laid over underfloor heating the trapped heat could damage the wooden floor. Always check your floor is suitable before installing UFH.

Laminates and vinyl

These are practical and versatile flooring choices, but it’s important to check the manufacturer’s recommended maximum floor surface temperature to ensure the floor covering is compatible with underfloor heating.

We recommend fitting a floor temperature sensor to protect more sensitive floor coverings.

Underfloor heating carpets

Are carpets suitable for underfloor heating?

Both water and electric underfloor heating can be used under carpet, but the combined tog rating of the carpet and underlay can be no more than 2.5. Otherwise, it will act as an insulator and stop sufficient heat reaching the room. Using carpet is feasible as long as the tog value (including the underlay) doesn’t exceed 2.5 and ideally is less than 1.5. Felt and rubber underlay may be less efficient than waffle-backed foam underlay.

Read our full underfloor heating guide to choosing the best floor covering

Can I have underfloor heating upstairs or in an apartment?

Underfloor heating joists For underfloor heating on upper floors, Nu-Heat’s ClippaPlate® can be fitted between or over the joists using a metal diffuser plate. These are installed from below before the ceiling is in place or above, before the floor deck is fitted, adding no height to the upstairs floor level. Here’s a video of what happens when you install underfloor heating upstairs.

We also have specialist acoustic UFH solutions to reduce airborne and impact noise between floors.

Water or electric – which types of underfloor heating are best?

With warm water underfloor heating systems, heated water is pumped around the property via a series of pipes embedded in the floor. Warm water systems are ideally suited to larger properties or those with lower levels of insulation, due to their higher heat output. These systems can be paired with renewables such as an air or ground source heat pump.

Electric underfloor heating consists of cables which are laid over the floor deck. These systems and kits are perfect for installation in small areas like bathrooms. They heat up quickly, but don’t retain the heat as well as warm water UFH.

‘Wet’ or ‘dry’ types of underfloor heating can refer to whether the system uses water or electric, but also whether it uses a liquid screed installation process as opposed to other methods. We can help find the best underfloor heating for you.

How is underfloor heating controlled – do I need new thermostats?

Nu-Heat offers a range of thermostats to suit every home, from simple use dial thermostats to smart control and home automation-enabled wired or wireless solutions. We’ll design your UFH to give you full control over your heating, with individual room-by-room temperature control and scheduling. We can even hide your thermostats away.

  • Dial thermostats allow you to set basic heating schedules and switch to holiday mode when you are going away
  • Programmable thermostats offer flexible control, allowing you to zone different rooms or areas of your house
  • Wired or wireless smart thermostats give you control of your UFH from anywhere with an internet connection

You can even connect your underfloor heating to your smartphone by installing an app, with certain packages. Any Nu-Heat underfloor heating system with a neoHub+ smart package is compatible with Apple HomeKit and Amazon Alexa.

Browse our full range of underfloor heating thermostats

Can I use underfloor heating with heat pumps and solar panels?

If you’re creating a more eco-friendly home, many types of underfloor heating can be paired with renewable options like solar thermal panels, or air source or ground source heat pumps. Here’s renewables and underfloor heating explained.

Underfloor heating heat pump

Underfloor heating is ideal to integrate with heat pumps, because of the low flow temperatures used by both components. UFH is not a limiting factor in such a system. The insulation level is crucial to design and, subsequently, performance. If insulation is sufficient, systems can be designed to the lowest temperatures, which can be less than 40°C.

Nu-Heat uses specialist software, developed in-house, to aid with the design process. Optimiser software establishes the most suitable floor heating scheme and determines the various technical requirements, including correct tube spacing for each room and optimum water flow temperatures. Our in-house predictor software is used to correctly size heat pumps.

Find out more about our renewable energy solutions

I have a boiler and radiators – can I have underfloor heating too?

No special boiler needed – underfloor heating works with gas, oil and LPG boilers as well as heat pumps. UFH can also be run alongside your existing heating system. Read our underfloor heating guide to combining UFH with radiators here.

Why should I choose a designed UFH system – can’t I just install a kit myself?

Properties of all ages can be suitable for underfloor heating, but just as no two homes are the same, neither are any two rooms in your property. We’ll carry out room-by-room heat loss calculations before designing the best underfloor heating for you; tailored for your home and how you use it. However, we do also offer underfloor heating kits in our shop.

Will my pets be safe sleeping on underfloor heating?

Nu-Heat is sure that the pets will be very happy. Underfloor heating is fine for dogs, cats and toddlers to sleep on.

Underfloor Heating Myths, BUSTED!

We’re glad you’ve found our underfloor heating guide useful so far. At Nu-Heat, we’re asked hundreds of questions about underfloor heating and how it works every day, many of them along the same lines and with the same worries.

Even now, there are still many common misconceptions about UFH. To help any homeowner, self-builder or installer who’s researching UFH for a project, we dispel the UFH myths.

Underfloor heating kitchen

Myth: Underfloor heating is unsafe and it can leak

Our underfloor heating tubes are extremely strong and will not leak. You would have to physically puncture the tube to create a leak, which takes considerable effort! There are never any joins in the tube other than at the manifold, so there are no weak points in the system where a leak could sprout. Take a closer look at a Fastflo tube here.

The tube we supply is quality assured to ISO9001 and is designed to the high European industry standard.

Myth: Underfloor heating takes a long time to warm up

Different underfloor heating systems offer different heat outputs and response times.

The use of the property is an important factor in choosing how underfloor heating should work. Some UFH systems heat up very quickly and are well suited to a property where the owners are regularly popping in and out throughout the day. Others are designed to store and release heat slowly, working well for someone that spends more time at home.

For example:

  • LoPro® systems are low profile, less than 22mm, so these offer a fast heat up time on par with a radiator.
  • ClippaPlate®, for upstairs UFH, holds tubes flush against the floor deck, so also offers a quick heat up time.
  • Screed underfloor heating, the most common system for new builds, holds the UFH tube in a thick layer of screed. This solution takes longer to heat up, but it also holds the heat for a much longer period.

Underfloor heating screed

Myth: Warm water underfloor heating isn’t suitable for single rooms

You can have warm water underfloor heating in just one room. Often customers would like to include UFH in a new extension without updating their heating system, and this is entirely possible. We offer OneZone® underfloor heating kits online that are ideal for single room UFH in various rooms. They can even run directly off an existing radiator circuit.

Myth: Electric underfloor heating is better for bathrooms and kitchens

The cheaper initial cost of electric UFH may seem tempting when installing in an area like a kitchen or bathroom, but as it’s an electric system, it is significantly more expensive to run – around three times the cost of warm water UFH – so it is best suited to smaller areas.

Warm water UFH is made up of many more components, so it does cost a little more upfront and to install. But you benefit from far lower running costs going forward, and it’s 25% more efficient than a radiator system.

There’s little point in installing electric underfloor heating in a large space if you can never use it due to eye-watering monthly bills.

Underfloor heating technical support

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