Underfloor heating pros and cons

Installing underfloor heating can be expensive and messy. But it's also an efficient way to heat a room without the need for radiators. 

In this guide, we explore the upsides and downsides of installing underfloor heating – according to owners.

We also include some expert advice on the types of underfloor heating, and how to make the most of your system. 

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Underfloor heating customer satisfaction

Underfloor heating is a high-spec feature that warms a room evenly and efficiently, while also giving the luxury of warm floors during cold winter mornings. It's particularly noticeable in rooms that have naturally cold stone or tile floors. 

But installing it involves considerable expense and upheaval, so it can be hard to know whether the benefits are worth paying for until you've already bitten the bullet. 

In May 2024, we asked more than 100 Which? members who've had 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 have 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 in our guide to underfloor heating costs and installation.

You'll also unlock thousands of product reviews, from boilers to vacuum cleaners. 

Underfloor heating pros and cons

We also asked our readers about the main advantages and disadvantages of their underfloor heating. 

Log in or join Which? to learn more about their experiences. 

To learn more about how much owners report spending on installing and running their heating, see our guide to underfloor heating costs and installation

Types of underfloor heating 

There are two main types of underfloor heating: electric and water. 

We did find that owners of one type of system were more satisfied on average. 

Log in or join Which? to see the results. 

Electric underfloor heating pros and cons

Electric underfloor heating consists of a wire, connected to the mains electrics, which heats up when the system is turned on.

Electric underfloor heating is quick and easy to install, so it's perfect for heating smaller rooms. 

It's also great if you're looking to install underfloor heating in your home without a full renovation. You may not even have to rip up your floors to install it. 

Water underfloor heating pros and cons

Water underfloor heating is a network of pipes through which warm water is pumped. The water is heated by the main heating element in the home, normally a gas boiler. 

Most people looking to invest in their underfloor heating choose a water system, as it's cheaper to run in the long term. 

Discover our expert advice for cutting your energy bills

Underfloor heating efficiency

In theory, underfloor heating is a very efficient way to heat your home. 

This is because it heats a large area, so it can run at relatively low temperatures (typically 35°C vs 55-65°C or even higher for central heating). 

In addition, it heats the room from the floor, and heat rises.

There are several ways in which you can control your central heating to make it more efficient. 

These include:

• Underfloor heating thermostats: You can get a programmable thermostat for your underfloor heating. This allows you to turn it on and off exactly when you need it, as well as changing the temperature. 
• Underfloor heating 'zones': You can build your heating so you have different 'zones' (areas of heating) that you can control independently. Zones can be separate rooms, or even different areas of a large room (a kitchen-diner, for example). 

Using underfloor heating as your primary heat source

As underfloor heating is an efficient system, it can be appropriate to use it as the only method of heating in a given room. 

However, if you do want to use an underfloor heating system as the only source of heat in a room, there are a few things to bear in mind:

• Use a system that's at least 200W per square metre (if it's electric)
• Ensure the system covers between 80% and 90% of your room's total floor area (wall to wall).
• The floor covering must have a relatively low thermal resistance so heat can get through it easily.
• You will also probably need to run the system at a higher temperature than if you were using it with another heat source.
• You'll need to install insulation boards beneath the underfloor heating to reduce the amount of heat being lost downwards.

If you live in an old property with solid walls and not a lot of energy-saving measures – such as no loft insulation and/or single-glazed windows – it's unlikely that underfloor heating will be sufficient to heat a room on its own.

In addition, underfloor heating typically takes between an hour and 90 minutes to heat a room (longer if it's poorly insulated), so you may need another system if you often need a quick burst of heat. 

Underfloor heating vs radiators 

The majority of people choose to use both central heating and underfloor heating in their homes – either in tandem or in different rooms. 

As with water underfloor heating systems, radiators contain pipes full of hot water, which is heated in the home’s main heat source (typically a gas boiler). 

Because they're a smaller system than underfloor heating, and wall-mounted, they're considered to be less efficient.

However, actual running costs can vary. 

For example, if you need to heat a single room, it will typically be cheaper to use radiators than electric heating (because gas is cheaper than electric). 

However, this will vary depending on your specific systems – for example, the number of radiators you have, and whether or not you can use your central heating to heat a single room. 

See our guide to floor insulation for more information about your options

Underfloor heating reliability

Underfloor heating systems rarely fail during normal working conditions as they're safely encased by insulation, screed and flooring.

In reality, they are more likely to be broken during installation than in day-to-day use.

To find out how likely it is to have issues, plus the most common ones, we asked underfloor heating owners to tell us whether they had had any issues. Fortunately the problems they reported were typically few and far between. 

Log in or join Which? to learn more about their experiences. 

Repairing underfloor heating

If a fault does occur, you will need to contact a specialist engineer to repair your underfloor heating. 

These engineers can pinpoint faults under a finished floor to within a few millimetres. This means they can then excavate a tile or section without having to lift the entire floor. 

For water underfloor heating, faults can be identified by using a thermal camera or a moisture tester. 

Look out for a warranty or lifetime guarantee

It's also worth keeping in mind that if a failure does occur, some companies provide warranties and guarantees, so can assist with fixing any problems. Make sure you look out for this when you buy. Some offer lifetime guarantees and/or cover accidental damage as well as systemic failures.

For added peace of mind, employ a qualified installer and check that the components they use are built to a set standard.

Use Which? Trusted Traders to find rigorously vetted underfloor heating specialists in your area

Underfloor heating FAQs

Below, we've answered some of the most common questions about underfloor heating. 

What temperature should underfloor heating be set at?

The maximum temperature you can set your heating to will generally be between 27°C and 29°C. However, experts generally recommend running your system at around 21°C to keep your rooms at a comfortable temperature. 

However, this all depends on the room you're trying to heat. For example, in a poorly insulated room you'll need to run the system at higher temperatures. 

At this temperature, the water in your system will be at between 35°C and 60°C, depending on the efficiency of your system. 

How long does underfloor heating take to heat up?

Underfloor heating systems are generally slower to heat up than radiators. If installed correctly, underfloor heating can take from 30 minutes to one hour to warm up. 

This could be an issue if you need immediate warmth in a room. If you have a programmable thermostat, you can use this to set your underfloor heating to warm up before you're going to be using the room.

Electric underfloor heating systems typically have faster heat-up times than water, but water tends to give a more constant heat.

How thick is underfloor heating?

The thickness of your heating will depend on the system that you choose, as they require different layers of material in order to run safely and effectively.

Water systems are generally bulkier than electric systems and can be around 130mm thick – thicker if it is retrofitted. 

Electric underfloor heating systems can be as thin as 42mm. 

How much upheaval does installing underfloor heating cause?

Although you can have underfloor heating fitted in most places, it might mean a lot of upheaval, especially if it's being fitted retrospectively to an existing room. 

If retrofitting in an existing room, the current flooring will usually need to be taken up, which may damage or destroy it in some cases. And the floor height might need to be raised, which may mean you need to reduce the height of the door to compensate. Plus, if this causes a disparity in floor height between one room and the next, you may need to put in a half-step between rooms.

Many people choose to have underfloor heating installed at a time when they're carrying out other refurbishments, to keep disruption and costs to a minimum. 

To learn more about the process of installation, see our guide to underfloor heating costs and installation