Underfloor heating

Underfloor heating heats the floor. As the heat radiates from the floor, the heat enters the room evenly and provides a consistent temperature. How an underfloor heating system heats the floor depends on the type of system you have.

There are two main types of underfloor heating. Regardless of the type you choose, the underfloor pipes or cables can be laid in different patterns depending on your needs.

Wet underfloor heating systems have a series of pipes laid underneath the floor. These pipes connect to the heating source (eg a heat pump or boiler), which sends warm water through the pipes, heating the space above.

With a larger surface area than radiators, you can heat your home with ‘wet’ underfloor heating system at lower boiler or heat pump flow temperatures. This will help save money on your energy bills compared to only using radiators.

Dry underfloor heating systems are made up of electric heating mats or cables that are laid underneath the floor. They generate heat when electricity is fed through them, which then heats the space above.

These systems can be effective for quickly warming small areas such as providing comfort underfoot in a bathroom. However, they can be costly to run over longer periods or in larger spaces. They’re like direct-acting electric heaters, which also rely on using electricity directly, and can be expensive compared to other heating options.

Materials conduct and radiate heat differently, so the type of flooring you have will influence how quickly your underfloor heating system heats a room.

While you’re probably not thinking “does this material conduct heat well?” when choosing your floor, it’s worth thinking about. You can balance style with energy efficiency by choosing a material that radiates heat quickly while fitting your overall aesthetic.

Yes, you can install it under carpets. But this can make it take longer to heat a room as it reduces how quickly heat transfers from the system into the room.

You should check that the tog rating of the carpet (including the underlay) to make sure it isn’t too thick for the heat to transfer. Home Building & Renovating recommends that the tog rating is 2.5 or lower. This will let heat transfer more quickly than higher tog-rated carpets.

The main benefits include:

• Having a consistent temperature in your rooms.
• A nice, cosy feeling underfoot.
• No need for radiators which take up wall space.
• Helps avoid furniture or curtains blocking heat distribution.

With wet systems, there are additional benefits:

• Easy to combine with low carbon heating systems like heat pumps.
• Lower energy bills as you can run the flow temperature much lower than with radiators, getting improved efficiency from a boiler or heat pump.

Heat pumps send water to pipes and radiators at a lower temperature than traditional gas or oil boilers.

Heat pump owners might benefit from larger radiators or underfloor heating because they have larger surface areas. This means they can emit more heat, so it takes less time to heat a room.

With underfloor heating, the flow temperature could be lower compared with radiators, and this should result in the heat pump running much more efficiently.

Generally, dry systems are cheaper to install than wet systems, but they’re more expensive to run.

How much it costs to install depends on what you need, what system you choose, and how complex the system is.

According to Checkatrade, the installation costs per square metre are:

• Dry (electric) system: £50 to £85/m²
• Wet (water) system: £85 to £110/m²

You can save costs if you’re already renovating your home, particularly if you’re already replacing the floor.

How much it costs to run depends on your own needs, but it can be a cost-effective way to heat your home. As we’ve mentioned, dry (electric) systems are generally more expensive to run than wet systems.

Pairing a wet underfloor heating system with a heat pump can be much more energy efficient than running a traditional gas/oil boiler with old radiators. However, how much you can save will depend on different things, including:

• Your electricity tariff, and oil or gas price.
• Whether you have it throughout the home or just downstairs.
• The type of floor material on top of the underfloor heating.

Sometimes installers will suggest underfloor heating for the ground floor of a building and install radiators upstairs. This can be less expensive to install and involve less disruption.

However, it’s important to select the right radiator sizes in this case: this is likely to be larger radiators with more panels included. Getting the right sized radiators will ensure enough heat is emitted in upstairs rooms, while keeping a suitable flow temperature for downstairs. 

Having underfloor heating throughout your home could mean you can achieve lower running costs with a lower flow temperature.

Installing these systems can be complex, so they should be installed by qualified professionals. A professional installer will be able to help you plan a system that fits your needs.

In a wet system, the installer needs to connect the pipes to a boiler or heat pump. If you’re getting underfloor heating as part of heat pump installation, the installer will consider this as part of the overall design.

A qualified electrician needs to connect a dry system to the power supply.

If you’re looking for an installer, we recommend finding someone reputable and experienced. You should get at least three quotes to ensure you can get the best deal.

You can use TrustMark to find a tradesperson in your area. TrustMark is a government-endorsed quality assurance scheme for work that you have done in or around your home.

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