Underfloor heating pros and cons

Installing underfloor heating, particularly a water system in an existing room, can be expensive and messy. But it can also be a great way to take the chill off a cold bathroom floor or potentially heat a room without the need for radiators. 

In this guide, we explore the upsides and downsides of installing underfloor heating according to people who've had it installed, and offer expert advice on where it can be installed and whether electric or water underfloor heating would work better in your home. 

Is underfloor heating worth getting?

Underfloor heating is a high-spec feature that allows you to enjoy the luxury of warm floors during cold weather, particularly if you have naturally cold stone or tile floors. 

But installing it involves considerable expense and upheaval, so there are some things you need to weigh up to decide whether it's right for you. We'd suggest thinking about your lifestyle and how you use your home. Are you mainly in the kitchen, or maybe always in late after work? 

These sorts of things will affect how much you'll actually use underfloor heating (and therefore whether it's worth getting), what room or rooms it makes most sense to have it in, and how you will need to set the timings to suit your needs.

Pros and cons of underfloor heating from owners 

Nobody knows the upsides and downsides of a product better than those that are already using it. So, we asked more than 100 Which? members* who've had underfloor heating installed what they love about it – and what they wish could be better.

If you're a Which? member, you can log in to unlock all our expert advice and insight from members who own underfloor heating to help you decide whether it's the right choice for you.  

Not yet a member? Join Which? today to unlock our advice and get access to exclusive underfloor heating cost data from the Royal Institution of Chartered Surveyors in our guide on underfloor heating costs and installation. You'll also unlock thousands of product reviews, from boilers to vacuum cleaners. 

Underfloor heating: common questions answered

Below, we've answered some of the most common questions about underfloor heating. Which? members can log in to get extra insights from homeowners who've already had underfloor heating installed. 

Is my home suitable for underfloor heating?

You can get underfloor heating fitted in pretty much any home – either when it's being built or by retrofitting it into an existing property – and under almost any type of flooring. 

Underfloor heating can be tailored to your needs, the room it will sit in and the flooring type, so that you get the right heat output for your home. 

Many of the owners we've spoken to said they got underfloor heating because they were renovating their house, so it made sense to have it done while work was being carried out. Others had it built into a new extension or conservatory.

As you might expect, bathrooms are the most popular room for underfloor heating to be installed. We found that:

• 53% of people have their underfloor heating installed in their bathroom
• 50% in their kitchen
• 25% in their living room
• 19% in their hallway.

Underfloor heating 'zones'

Underfloor heating also allows you to 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). This is useful if you know you will be in one 'zone' a lot more than others, or at certain times. 

Should I install electric or water underfloor heating?

As is often the case, there's no categorical answer to this; there are pros and cons to both types of underfloor heating. The best type for you will depend on factors such as:

• the size and shape of the area you're heating
• whether you're installing the system under an existing floor
• whether you're installing the system as part of a full property refurbishment or new-build project. 

As a general rule, water underfloor heating typically requires more space for the pipes so may mean floor levels in existing rooms needs to be raised, and is more complex and costly to install, but is likely to be cheaper to run once its in place. Electric underfloor heating is more expensive to run, but tends to be easier and cheaper to fit. Competent DIYers can even install some systems themselves, although you'll need to hire a qualified electrician to connect it to your electricity supply.

Most (62%) of the people we asked who have underfloor heating have an electric system, while 38% have a water system. 

Our tables below give an at-a glance comparison of the pros and cons of electric and water underfloor heating.

Electric underfloor heating pros and cons

Water underfloor heating pros and cons

Can I install underfloor heating myself?

Some off-the-shelf products are available for competent DIYers to fit. However, this is better suited to electric underfloor heating, especially if you buy it as mats with the wires attached, rather than loose wires. Water underfloor heating can be more complex to install, so is usually best done by a professional installer. 

How to minimise the risk of faults and deal with damage

If underfloor heating isn't fitted correctly, there is more of a risk of a fault occurring – and you don't want to discover this after you've already laid the flooring on top. To avoid this, make sure you follow the supplied manual and test the system before it's covered.

If you damage an electric system during installation, you can buy repair kits for around £20 that may help fix it, depending on the nature and scale of the damage.

Employing a professional to install underfloor heating will cost more upfront, but also means they're responsible for dealing with any problems that do occur. Trade association BEAMA stresses the importance of selecting a suitable installer. It says: 'A professional will take the time to correctly size the system, taking into account the floor covering and the necessary type of controls. Before leaving they will then take time to explain to the customer how to use the system.'

If you'd prefer to get a professional in to install your underfloor heating, use our Which? Trusted Traders search tool below to find an installer that's been vetted and approved by Which?. You don't have to be a Which? member to use Which? Trusted Traders.

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. 

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Is underfloor heating expensive to buy?

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

The exact cost of the system itself will depend on the size of the space and how well it's insulated. Larger rooms or those that aren't insulated might require bigger systems or ones with higher wattages, which will cost more. 

Plus, there are expenses to consider above and beyond the cost of buying and laying the underfloor heating itself. If retrofitting in an existing room, the current flooring will need to be taken up, which may damage or destroy it in some cases. And the floor height might need to be raised, which will affect the door and ceiling height. All of this will mean more work for the installer, which adds to labour costs. 

Our guide to underfloor heating costs details more on this, but we recommend speaking to a heating engineer as a first port of call, to decide whether the work and cost of underfloor heating will make it prohibitive for your home.

You can use Which? Trusted Traders to find a recommended heating specialist in your area. All traders that bear our logo have been through extensive background checks.

Does underfloor heating cost a lot to run?

Running costs for underfloor heating depend on many of the factors we've mentioned above: how many rooms it's in, the insulation of the room and floor, the size of the room, whether it's replacing radiators and, of course, how much you have it switched on. Electric underfloor heating in particular can be quite expensive to run (water systems tend to be cheaper to run), so it's worth bearing this in mind before having it installed.

Log in or join Which? to check what owners that responded to our survey feel about running costs.

Thermostats offer flexibility and can keep costs down

As with central heating systems, you can get a programmable thermostat for your underfloor heating. This will enable you to turn it on and off exactly when you need it, as well as changing the temperature, so you can maximise the efficiency and keep running costs down. 

It also means you can control it separately from your central heating. In fact, each room with underfloor heating can have its own thermostat, giving you ultimate flexibility. This enables you to adjust just one room at a time to fit your needs and lifestyle, so heat isn't wasted when it's not needed.

If you like simplicity, get a streamlined thermostat with simple on/off controls. Or if you're into high-tech features, there are touchscreen or smart versions with lots of options, and which let you control the system from your smartphone.

Can underfloor heating replace radiators?

Potentially. Replacing bulky radiators with underfloor heating can free up space and give a cleaner decorative finish. 

However, if you want to use underfloor heating as a room's primary heat source, 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'll need to install insulation boards beneath the underfloor heating to reduce the amount of heat being lost downwards.

It's worth keeping in mind that you will probably need to run the system at a higher temperature than if you were using it with another heat source. 

Extra heat in certain situations

If it's not possible to meet the criteria above, you may need additional heat, such as a heated towel radiator or plinth heater, for really cold days. 

Smaller or less powerful systems will keep your floor warm, but won't necessarily heat up the rest of the room, especially if the wattage is lower or it's a room with external walls and the weather is very cold outside.

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.

Many of the underfloor hearing owners we asked said it wasn’t a total replacement for radiators and that they had to use a second heat source if they needed heat quickly.

Is underfloor heating efficient?

It depends on a number of factors. Compared with radiators, underfloor heating is more consistent, so is theoretically more efficient. But that doesn't mean it's less costly. This is in part down to the fact that most people have electric underfloor heating, and the high cost of electricity compared with gas (which most people use to heat radiators) makes electric underfloor heating comparatively pricey to run. 

Radiators

• need heating to a higher temperature, usually at least 55-65°C
• rapidly heat the area immediately around them
• the heat rises and cools down as it's slowly distributed around the room.

Underfloor heating

• runs at lower temperatures, as low as 35°C
• heats a larger surface area, from the floor upwards
• provides a more consistent temperature across the whole room.

Underfloor heating needs the right conditions to be efficient

You'll also need to keep in mind a number of factors that can determine how efficient underfloor heating is, such as:

• what type of system you choose
• the flooring and insulation you have
• the size of the room you're installing it in. 

How long does underfloor heating take to warm 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 to speed up the heat distribution

How quickly the heat is distributed depends to some extent on the floor covering and insulation. 

You can speed it up by using flooring that will conduct heat easily, such as tiles. 

Some floor types will also hold heat for longer, even after the system is turned off. For example, stone will retain heat for longer than vinyl flooring. Making sure your underfloor heating is fitted evenly, and on sufficient insulation boards, will also help to spread the heat more quickly.

Are there any common problems with underfloor heating? 

When we spoke to underfloor heating owners about their experiences, there were a few niggles that cropped up more than once. 

Log in or join Which? to unlock their feedback so you know what to expect.

Can underfloor heating systems be easily repaired?

If you're thinking of installing underfloor heating, you may have concerns about the risk of something going wrong with the system, or needing to replace it after a number of years. 

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

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

If a fault does occur, especially if you're not sure where the damage has occurred, 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.

You can use our independent trader service, Which? Trusted Traders, to find someone in your area who has been through our tough vetting process.

* In December 2021 we surveyed 119 Which? members with underfloor heating about their experiences with it in the past five years.