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Underfloor heating explained

Electric underfloor heating

By Liz Ransome-Croker

Article 1 of 4

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Electric underfloor heating

Is electric underfloor heating right for your home? Read on to find out how it works, how it's installed and how much it costs to buy and run.

Underfloor heating can help to keep floors and rooms warm, and offers a space-saving alternative to radiators. But is electric underfloor heating right for you? Our guide will help you to decide.

There are two main types of underfloor heating: electric, which is also known as a dry system, and water underfloor heating, also called a wet system. 

When we asked owners of underfloor heating about the type they have in their home, most (65%) said they have electric underfloor heating, and 35% have water*. 

We've spoken to experts in the  industry, including The Underfloor Heating Store, Warmup Plc and Polypipe, as well as owners of underfloor heating, to bring you the inside track on whether this type of heating is right for you and how to get the best out of it.

On this page we look at how an electric system works, how it's installed and how much is costs. You can jump straight to the question you want answered by clicking on the links below.

If you want to know what owners consider to be the benefits and drawbacks of underfloor heating, visit our pros and cons page.

How does an electric underfloor-heating system work? 

In an electric system, a series of electric wires or heating mats are installed beneath your flooring. 

Electric systems vary in terms of wattage, from around 100W to 200W per square metre. But the system and wattage you choose will depend on:

  • the size and shape of the room
  • how well insulated the room is
  • what the flooring below it is like
  • the type of flooring you'll have on top. 

Electric underfloor heating is usually placed on top of a layer of floor insulation - to ensure the heat travels upwards rather than down. This is first laid on a layer of screed (made of sand and cement) or suspended timber (floorboards on joists), to ensure the surface is completely flat.

The heating wires are then connected to your mains supply. It will also include a sensor to help regulate the temperature. You can then use a thermostat to control the temperature and pre-set the system to turn on or off. 

You can buy underfloor heating mats and wires from DIY stores such as Wickes and B&Q, as well as from specialists such as The Underfloor Heating Store.

If you want advice on which type of system is best for you, use Which? Trusted Traders to find a reputable underfloor heating installer near you.

What temperature does electric underfloor heating need to be?

Electric systems will run at approximately 25-31°C on average. But it will depend, in part, on the type of flooring you want to have over it and what the floor underneath is like. These aren't the only factors that can affect it - visit our page on underfloor heating cost and installation to find out more.

Where can it be installed? 

You can have it installed anywhere you can get a power supply to. But because electric underfloor systems can be more costly to run and less powerful than water systems, they're generally better suited to smaller rooms, such as bathrooms.

66%of people have electric underfloor heating in just one room

The majority (66%) of people we spoke to with electric underfloor heating had it installed in just one room, most commonly in their bathroom (63%), followed by the kitchen (32%). 

How do you install electric underfloor heating mats or wires?

The mats consist of a series of wires that are attached to a mat at even intervals. These can be laid across a smooth and level floor, and insulation placed on top. 

Loose wired systems don't come on a roll, so can be laid however you want them. This makes them a lot more flexible if you have an awkward-shaped room. However, you'll want to ensure the wires are evenly spaced, or the heat won't be evenly distributed across the floor. 

Because electric systems are generally quite thin and simple to fit, they can be easier and less hassle to install in an existing room than a wet heating system, which requires some space for pipework and could involve the floor being raised.

Most people choose to employ a professional company or trader to install underfloor heating. Professionals are best placed to recommend what system to install and how to prepare the floor.

If you are a confident DIYer, you could feasibly install the heating sheets or cables yourself – but you'll need a qualified electrician to connect your system to your electric mains supply.

79%of people used an expert to install their electric underfloor heating

79% of the people we asked who have electric underfloor heating got a company, builder or supplier to install it. This is a smaller percentage than those with water underfloor heating – 86% used a company, builder or supplier. Just 12% fitted it themselves (eight people). 

You can use Which? Trusted Traders to find an underfloor heating installer in your area. We rigorously check the backgrounds of all the traders and companies we recommend, so you don't have to. 

How much does electric underfloor heating cost to install and run?

Costs for roll-out underfloor heating mats start from around £300 for a kit with 10 square metres (150V). You'll also need to factor in the cost of insulation board, self-leveling compound (such as a sand and cement screed) if the floor needs evening out, and heating controls. 

Obviously, if you install it yourself, that won't cost anything. But you will need to pay an electrician's call-out and labour charges.

We've researched the cost of installing electric underfloor heating, and asked installers across the UK to tell us what can affect the price. You can find out more by going to underfloor heating cost and installation.

While electric underfloor heating is cheaper to install than a wet system (and you can even do it yourself), it's more expensive to run. For that reason, many of the installers we spoke to don't recommend an electric system for large areas.

To find out what owners of underfloor heating think about the running costs, whether it saved them money on their heating bills, plus the benefits and drawbacks of getting it installed, go to the pros and cons page.  

(*In November 2017 we asked 104 Which? members with underfloor heating about their experiences with it in the last five years.)