Homeowners Professionals

Underfloor heating vs. radiators

Wondering how much it could cost a month to run your gas fire? Viessmann reveals how you can work this out yourself.

In the past, radiators were the automatic choice for many when it came to heating their home. These systems carry the hot water from your boiler to each room in your home before returning to the boiler to be heated again.

However, modern technology has introduced another way for us to make our homes toasty and warm - underfloor heating (UFH). While previously thought of as a luxury, the system’s popularity has soared in recent years and more and more people are choosing to have these systems installed as a way of making their home more efficient and more comfortable.

Below, we compare underfloor heating vs. radiators, discussing the pros and cons of each, to help you decide which is the best system for you.

Underfloor heating: pros and cons

There are two types of UFH - wet and dry, also sometimes known as water and electric. A wet system works in a similar way to your radiators - with warm water being pushed through the pipe network to deliver heat from the floor up. A dry system uses electricity to heat a series of cables that are laid underneath your flooring.  

Underfloor heating: pros and cons

Works at a lower flow temperature - If your flooring got as hot as the surface of a radiator, you’d burn your feet and barely be able to walk on the floor! Not only that, but it would take a huge amount of energy to sustain such heat. UFH is designed to work at much lower temperatures than your radiators (around 30 to 40 °C, instead of up to 70 °C). In this way, it can spread the heat more efficiently and evenly throughout the room to make it a comfortably warm space without wasting energy unnecessarily.  

Gives you more control - UFH systems allow greater control. As they spread the heat more evenly throughout a room, the thermostat may be more accurate and so you can more precisely control the temperature of that space. You may be able to zone the system so that some rooms are warmer than others, too. Such precision could make your home more efficient and reduce energy wastage.

Lasts longer than radiators - Generally, an UFH system has a longer lifespan than a radiator. Radiators may become rusty or could simply need replacing to improve their efficiency, whereas a wet UFH system can last as long as 50 years.

Frees up wall space - When you have UFH installed, you wouldn’t know it was there. All the pipework or cabling (depending on whether you have a wet or dry system) is located underneath the floor, which gives you more wall space for furniture or other household items.  

Works with a heat pump - UFH can work alongside a heat pump to make your home even more energy efficient. An electric system can also use renewable energy if you have solar panels installed.

Reduces the risk of burns - As the heating system is installed underneath the floor and it runs at a lower temperature, there’s no risk of children burning themselves on a hot surface.

Underfloor heating cons

As you can see, there are a lot of benefits to an UFH system, but there are some drawbacks too.

Higher initial cost - UFH is more expensive to install than simply replacing existing radiators. While some systems can be retrofitted, the installation involves removing your current flooring so that the pipes or wires can be laid and then reapplying your flooring over the top again. For this reason, it’s often easier to install in new builds or if you’re undertaking a renovation/extension. The cost of the system itself is also more than buying new radiators, however, the increased efficiency of UFH could save you money long-term.

Difficult to replace - It can be tricky (and expensive) to replace underfloor heating should it stop working.  

Heats your home more slowly - An UFH system may take longer to heat a room to a desired temperature than a heating system with radiators. While this problem can be fixed by adjusting your programme (for example, you could set the heating to come on a bit earlier than you’d expect anyone to be home), it means you may have to wait a while for a room to warm up if you’re very cold. It’s worth noting that dry UFH heats up faster than wet UFH.

Works best in a well-insulated home - if your home is quite old or poorly insulated, then an underfloor heating system may not be the best choice for you. These systems are designed to run for longer at a lower temperature, but should too much heat escape, it could struggle to keep your home at the temperature you’ve set.

May not work with all types of flooring - Not all flooring is UFH-compatible, so it’s worth checking that your desired flooring can be installed with such a system. For example, some types of flooring, such as ceramic and stone tiling and resin and polished screed, are very good at conducting heat. Vinyl, linoleum and solid and engineered wood flooring are also known to perform well. Laminate flooring can also be a good option - however, it should be noted that high temperatures (above 27˚C) are likely to result in damage to the flooring so should be avoided. Carpets and rugs, however, are less suitable for UFH systems as they don’t transfer heat well.  


Radiators: pros and cons

Unlike UFH systems, which work using radiant heat, radiators work via convection, meaning they heat the air around them. This air rises upwards when it’s warm and then sinks again as it cools. Below, you can find the pros and cons of a radiator system to compare it to underfloor heating.

Radiator pros

Easy to replace - Should a radiator need replacing, it’s fairly easy to find one that’s the same size and do a like-for-like swap at a good price with minimal mess. In fact, it’s recommended that you do replace radiators that are very old for more efficient equivalents.  

Come in a range of designs - Who said radiators can’t make a statement? There are hundreds of designs and colours to choose from to ensure that your radiators look stylish and are in keeping with the rest of your home interiors. For period properties, you can find modern radiators that look old, whereas for contemporary homes, you can have vertical or slim radiators to take up less space.

Provide heat quickly - Thanks to their ability to blast out a high temperature, radiators can heat your home up quite quickly when you feel chilly during the winter. They can also be used to dry clothes on should you have a few items that you don’t want to put in the tumble dryer.

Radiator cons

Radiators remain the most popular way of heating a home, but this doesn’t mean they are the best or most effective option. Technology has come a long way since the first radiators were used in UK homes in the 19th century, and now, a system that uses radiators may be seen as outdated and inefficient. Below, you can find some of the cons of radiators.  

Cold spots and draughts are common - Radiators work by sending out a lot of heat from a small surface area. As the air heats up, it rises to the top of the room and then sinks as it cools back down. This creates a circular motion, but it means that only parts of the room are at your desired temperature, and you may be left with cold spots that are unheated. When this is the case and you feel a bit chilly, it’s tempting to increase the temperature of the radiator with the thermostatic radiator valve (TRV), using more energy. This reduces the efficiency of your heating system and may not solve your problem, either.

Doesn’t allow for proper room temperature control - While radiators can be controlled via their TRVs, these may not be the most accurate way of getting a room to a particular temperature. This is because radiators blast out a lot of heat from a small surface area that then rises to the ceiling, meaning the TRV can take an inaccurate reading. Radiators can also be used in conjunction with a room thermostat, but because of the cold spots caused by radiators, their accuracy may be inadequate too.

Have a reduced lifespan - Unlike UFH, which can last for decades without needing to be replaced, radiators tend to have a lifespan of around eight to 10 years.  

Reduced wall space - Radiators shouldn’t be blocked by curtains or furniture, as this reduces their efficiency and prevents the heat from penetrating into the room. If they are obscured, you may just be heating the sofa or sending the heat straight back out the window from behind the curtains. But sometimes, the location of a radiator makes it impossible to not block it, and it may be the only logical place for an armchair or other piece of furniture to go.  

Dirt can reduce their efficiency - The water that’s running through our heating systems isn’t crystal clear - it’s usually full of dirt that has entered the system, but also rust from the copper pipes and limescale from hard water. This dirt can build up and make our radiators much less efficient. In some extreme cases, it may block the hot water from getting into the radiator entirely. While this can also be the case for wet underfloor heating, an electric equivalent won’t have the same problem.  

Can cause irritation for those with allergies - Dust can get trapped behind our radiators, but also in between the individual pipes inside them. Because of the way a radiator works (the hot air around the radiator rises and then sinks, creating a circular movement around the room), this dust can be carried as minute particles that you can’t see. Therefore, for people with allergies or for whom dust is an irritant, radiators may not be the ideal heating solution.

Is underfloor heating more efficient than radiators?

Whether underfloor heating is going to be a better, more efficient option than radiators will likely depend on factors including the size of your home, the number of radiators you have already, the size of the UFH (m2), etc. There are lots of variables involved and so it can be difficult to come up with a specific figure to say whether UFH is more efficient.

A wet UFH system is powered by your boiler, and boilers are sized in kW (24 kW, 36 kW, etc.). This means that a 24 kW boiler will use 24 kW of gas per hour that it’s running, and so a boiler that is on for four hours a day will use approximately 96 kW of gas. This would provide your home with both heat and hot water.

However, radiators generally require much more energy to keep them at a consistently hot temperature (about 70 °C) and UFH by comparison can run at much lower temperatures (30 to 40 °C). This could mean that UFH won’t put as much demand on your boiler, and so it could be the more efficient system.

Dry UFH systems use electricity instead of gas, and the average size system in the UK is around 100 W/m2. This means it uses 100 watts per metre square of heating if the system was left on all the time. Should the system be left on for 12 hours instead, it would use around 50 W/m2. As an example, a kitchen that is 24 m2 will use around 1,200 W (or 1.2 kW) of electricity per hour.  

To put this into perspective, a fridge uses around 1.2 kWh of electricity per day, and so running a fridge for 24 hours uses around the same amount of energy as putting on the UFH for one hour in a 24 m2 room.  

Compared to radiators, it’s thought that UFH uses around 25% less energy, making it the more energy efficient option. When you use a dry UFH system with a heat pump, you could see even more energy savings.  

Can underfloor heating replace radiators?

Yes, underfloor heating can replace radiators altogether if you want your entire home to be heated from the floor up. You don’t need both in order to keep your home at a suitable temperature throughout the winter months. However, underfloor heating may not be ideal for very old buildings or for homes with a lack of insulation.

Can you use underfloor heating and radiators together?

While you can do away with radiators altogether in favour of underfloor heating, you can also choose to use both systems together. This may be the better option for many people who don’t want to replace the whole system, or are doing a renovation and only installing UFH in part of the house. 

You may choose, for example, to have UFH downstairs and keep your radiators upstairs. Alternatively, you could have UFH in a room you use the most, such as a kitchen or living space, and radiators everywhere else. You might even choose to just have UFH installed in rooms that have cold floors, such as the kitchen and bathroom - your feet will thank you on a cold morning!

Radiators or underfloor heating: which is better?

The type of heating system you ultimately decide on may depend on your lifestyle and the home you have. 

In a well-insulated, modern home, UFH could be the best option for you. Not only is it more efficient, but you can do away with radiators altogether and spread the heat more evenly throughout your home. You may also have greater control over the temperature in the property and you’ll likely see a reduction in cold spots and draughts. 

Should you have an older property that has less insulation, radiators may still be your best option. They will continue to be around for a long time to come because they do heat a space relatively quickly, despite perhaps not being the most efficient way to do so. Many people prefer them as they’re a system we feel comfortable with, but they’re also easy to replace should the need arise.

How can we help?