How to choose the best electric underfloor heating system

If you're looking for the luxury of a heated floor with minimal installation costs, electric underfloor heating could be a tempting choice. 

Electric underfloor heating is more expensive to run than central heating or water underfloor heating, but it's cheaper and less disruptive to install. 

This guide explains everything you need to know, including how it works and where you can use it. 

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How does electric underfloor heating work?

Electric underfloor heating consists of a long wire that is coiled underneath your chosen flooring.

This wire is connected to the mains electricity supply. When the system is switched on, the wire gets hot and it heats your floors and warms up the air in the room. 

 It's placed on top of a layer of floor insulation, to ensure that the heat generated travels up instead of down. 

Electric systems run at approximately 25-31°C, on average, depending on how warm you set them. 

The temperature you choose will depend, in part, on the type of flooring you have on top of it and what the floor underneath is like. 

Electric underfloor heating systems vary in terms of wattage, from around 100-200W per square metre. The wattage and size will affect the running costs. What 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.

It can't be put underneath solid wood flooring, as the frequent temperature changes can cause the wood to warp. It can be put under carpet, but thicker carpets may trap the heat, making it less efficient at warming the air around the room.

Types of electric underfloor heating

Underfloor heating comes in two main forms:

• Mats These consist of a series of wires attached to a mat at regular intervals. The mats can be cut to size (avoiding cutting through the wires themselves), and laid across a smooth and level floor. The flooring is laid on top of this. Mat-based systems are easier to install, but they may not be as good for small or irregularly shaped rooms, as you have to work around the placement of the wires. 
• Loose wires These can be laid however you want them, making them a lot more flexible if you have an awkwardly shaped room. However, you'll need to ensure that the wires are evenly spaced or the heat won't be evenly distributed across the floor. 

Electric underfloor heating thermostats

Electric underfloor heating thermostats are usually wall-mounted in the same room as your underfloor heating. They let you adjust the temperature of your underfloor heating to the level you prefer, helping ensure that the system runs efficiently and keep costs down. 

You'll need a separate thermostat for each room you have underfloor heating in. 

There are a few different types of thermostat, ranging from simple to sophisticated:

• Manual dial/traditional thermostats These simple models are controlled manually by turning a dial, for example.
• Programmable thermostats allow you to select when you want the underfloor heating to turn on and off, and its temperature.
• Smart thermostats let you manage your underfloor heating from a distance, typically using a smartphone app.

When scheduling your thermostat, bear in mind that underfloor heating takes longer than radiators to heat up. If you want to wake up to a toasty room first thing in the morning, set it to turn on at least half an hour before your alarm clock. 

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Electric underfloor heating costs

Electric underfloor heating is cheaper to install than water underfloor heating because installation is less intrusive. However, as it uses electricity, it's generally more expensive to run.  

Based on manufactuers' estimates and an electricity price cap of 24.5p per kWh (October - December 2024), we estimate running costs start at around 36p per hour for a 10 metre square room. This can quickly add up if you want it to run for a few hours a day and/or have a bigger space to heat. 

Actual running costs for underfloor heating systems will vary considerably, as they are impacted by factors such as:

• Your home's insulation
• The size of the area to be heated
• How long the system runs for
• Your energy tariff.

Check our guide to underfloor heating costs and installation to find out the typical prices for different scenarios, based on information from the Royal Institute of Chartered Surveyors (RICS). 

Electric underfloor heating installation

It's possible to lay electric underfloor heating yourself, although you'll need a qualified electrician to connect it to your electricity supply and add a thermostat. 

However, if you're not that confident with DIY, we'd recommend using a professional. 

They will be able to consult on the suitability of your rooms for electric heating and the best type, as well as preparing and insulating your floors and installing the wiring. They will also be able to draw up a plan for where wiring will go in order to heat the room most efficiently and effectively. 

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 do you install electric underfloor heating?

When installing electric underfloor heating, it's important that your floor has been prepared and insulated in the best way for the floor type and its location in your home. Then it should be a simple case of laying and taping down the wires.  

A self-leveling compound (such as screed) can also be applied to the top to keep the wiring in place, but whether this is needed depends on how even the floor is already, and what flooring you'll be putting on top. 

A qualified electrician will need to connect it to the electricity supply and install the thermostat.

Where can electric underfloor heating be installed?

You can have electric underfloor heating installed anywhere you can get an electrical power supply. 

However, as electric underfloor heating is more costly to run and less powerful than water-based systems, it's generally better suited to use in single, small rooms.

In May 2024, we asked 77 Which? members with underfloor heating where they had it installed. 

The majority (53%) of people had it installed in just one room. They typically had it installed in their bathrooms (46%) or their kitchens (21%). 

Electric underfloor heating thickness

Electric underfloor heating is typically less bulky than water systems, which is useful for rooms with low ceilings if you are keen not to have raise the level of your floor. 

Insulation for electric systems can be as little as 25mm thick and the wire itself as small as 4-5mm thick. 

Overlays for electric heating, such as padding or scree, generally range from 12-30mm

Read more: our guide to underfloor heating costs and installation

Is electric underfloor heating worth it? 

It can be hard to know whether the benefits of electric underfloor heating are worth paying for until you've already bitten the bullet. 

So, in May 2024, we asked 77 Which? members who have had electric underfloor heating installed whether they think it was a worthwhile investment. 

If you're a Which? member, you can log in to unlock our insights from members who already own underfloor heating.

Not yet a member? Join Which? today to see our advice, as well as exclusive underfloor heating cost data from the Royal Institution of Chartered Surveyors (RICS) in our guide to underfloor heating costs and installation.

Electric underfloor heating reviews

Log in or join Which? to read verbatim reviews from our members. 

Read more: our guide to the pros and cons of underfloor heating

Electric underfloor heating FAQs

Is electric underfloor heating expensive to run?

We estimate that it costs upwards of 36p per hour to run electric underfloor heating in a 10 metre sqare room. 

It is more expensive than using gas heating (such as central heating with radiators). 

However, if you want to heat a single room that's not too big and that you don't need to be warm all day long - a bathroom, perhaps - it is a nice luxury. 

How long does electric underfloor heating take to warm up?

Electric underfloor heating typically takes 30 to 90 minutes to warm up, depending on factors like insulation, floor material, and system power. 

Thinner flooring materials like tiles or laminate heat up faster than thicker materials like concrete. 

Can you use electric underfloor heating with wooden floors?

You can't use electric underfloor heating with solid wood floors.

Wood expands and contracts with temperature and humidity changes, so direct heat can cause the wood to warp, crack, or gap over time - especially with thicker planks.

However, you can use electric underfloor heating with engineered wood, as it is designed to be more resiliant. 

Can you use electric underfloor heating below carpet?

Yes, underfloor heating can be used below carpet. 

However, you will need to ensure the  the carpet and underlay have a combined thermal resistance (TOG value) of less than 2.5. 

TOG indicates how much it blocked by your carpet. If it is very high, it will trap the heat form your underfloor system below your floor and it will not heat the room.