Underfloor heating pros and cons

Installing underfloor heating can be expensive and disruptive. But once in place, it's 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 real owners.

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

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

Underfloor heating pros and cons

It's hard to know if underfloor heating is worth paying for until you've bitten the bullet. In May 2024, we asked more than 100 Which? members with underfloor heating to tell us the main advantages and disadvantages.

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.

Is underfloor heating worth it?

To find out if real owners think their underfloor heating was worth the expense, we asked our survey respondents to rate their overall level of satisfaction with their underfloor heating. 

Log in or join Which? to see what they said. 

Underfloor heating efficiency 

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 compared to 55-65°C or even higher for radiators). 

In addition, it heats the room from the floor, and heat rises, so you get a more even distribution of heat.

Underfloor heating vs radiators 

As with water underfloor heating systems, radiators heat the room using pipes full of hot water. However, as they are much smaller and run at higher temperatures, radiators are less efficient.

In practice though, running costs can vary. 

Electric underfloor heating is generally more expensive than radiators, because gas is cheaper than electric. However, if you want to heat a single room, and you can't set your central heating to heat a that room only, it will be cheaper to use electric underfloor heating. 

It will generally always be cheaper to heat a room with water underfloor heating than radiators. 

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.

Compare water and electric heating in our guide 

Underfloor heating reliability and problems

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 damaged 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.

If you're updating your central heating, see our guide to the best boilers

Underfloor heating FAQs

How long does underfloor heating take to heat a room?

Underfloor heating takes between an hour and 90 minutes to heat a room (electric underfloor heating is slightly quicker than water). 

However, this can take longer if the room or underfloor heating system is not well insulated. For this reason, you may want to consider another heating system (even a portable space heater or similar) if you need a quick burst of heat). 

How thick is underfloor heating?

This 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. 

What is the best flooring for underfloor heating?

Tiles and stone are the best flooring for underfloor heating, because they conduct heat efficiently. 

You can use underfloor heating with most types of thin carpet, engineered wood, vinyl and laminate.

You shouldn't use underfloor heating with thick carpet (because it traps too much heat) and solid wood (because it becomes warped by the temperature changes).