Does underfloor heating need to be on all the time? Experts explain why it could actually be better for your comfort and bills

Central heating season is once again upon us but, in the face of yet another rise in energy prices, many people are understandably trying delay turning it on.

While there are ways of keeping a house warm without central heating, there comes a time when the big switch on is inevitable. That said, there are ways of using your central heating more efficiently when it is up and running – including when you choose to turn in on and off again.

In the case of underfloor heating, the way in which you operate your system, as well as the temperature you set it at can have a huge effect on both your comfort levels as well as how much it costs you to run. Some experts advise leaving it on all the time to maximise its benefits – but is this really the best idea? I did some digging.

Is it a good idea to leave underfloor heating on all the time?

There is much speculation about whether it is cheaper to leave central heating on all day, but when it comes to households with underfloor heating, there are several factors to take into consideration when it comes to how best to operate it.

Ben Gallizzi, energy expert at Uswitch, explains that in many cases, rather than leaving your UFH running continuously, it is better to think about your routines and schedule it to come on and off as needed. 'Underfloor heating doesn’t necessarily need to be on all the time, but it does need to be managed slightly differently from traditional radiators. Since it takes longer to heat a room, switching it on only when you feel cold may mean you’re waiting a while for the room to reach a comfortable temperature. Using a timer or central heating controls can help households plan ahead and have the heating come on when they actually need it, rather than running it continuously."

However, Martyn Fowler, founder of Elite Renewables, goes on to explain that, during colder months, a low-and-steady approach can be best if you want to keep a lid on your underfloor heating costs. 'It doesn’t need to be on all the time – but I wouldn’t keep turning it on and off either if it’s a wet system under a screed floor. The floor takes time to heat up and it holds onto that heat for quite a while. It generally works better with a steady temperature rather than turning off and on constantly and heating the floor from cold.

'If nobody is home, I’d turn the temperature down – I wouldn’t necessarily switch a slow system completely off for a couple of hours,' adds Martyn. 'Turning it down a few degrees usually makes more sense.'

Martyn Fowler

Founder of Elite Renewables, Martyn Fowler is one of the UK's leading renewable technology experts, working with heat pumps for the last 2 decades. His passion for decarbonisation matched with a deep technical experience of the technology make him one of the industry's go-to experts for all things renewable.

Ben Gallizzi

Ben joined Uswitch in December 2018. One of the biggest challenges he’s been involved with since becoming part of the energy industry was the energy market crash in 2021. It was important to make sure that customers were being supported and informed when they came to Uswitch at a time when cripplingly high energy bills were putting most people under severe financial pressure. Uswitch was then and continues to be a key resource for customers looking for energy clarity.

When should you switch underfloor heating off?

Even if, during the winter, you choose to leave your underfloor heating on a continuous low setting, there will be times when it is a better idea to turn it off altogether, particularly if you have electric UFH, as Simon Bones, founder and CEO of Genous, explains. 'Underfloor heating comes in two flavours, wet (hot water running through the pipes) and dry (electric matting running under the floor). Electric underfloor heating is expensive to run and you are best off using it only when it is needed and/or when electricity is cheap (if you have solar panels or a battery and/or a time-of-use tariff) as it’s not economic to use it as an always-on solution.'

'If you’re going away for a few days or you don’t need the heating, there’s nothing wrong with turning UFH off,' picks up Martyn Fowler. 'If you’re only going out for a couple of hours, I probably wouldn’t bother. I’d just turn the temperature down a little. Otherwise you can come home to a cold floor that takes hours to warm up again.'

Simon Bones 

Simon Bones is the founder and CEO of Genous, the UK's only premier home retrofit company. He is also a Visiting Research Fellow in climate change science at the University of Bristol.  Paving the way for a greener and energy efficient future, Simon and his team of experts help people find eco-friendly solutions to retrofit their homes and save money in the long-term.

Is there a ideal underfloor heating schedule?

While the idea of there being an ideal central heating schedule to keep your house warm all winter is an appealing one, sadly there is no one-size-fits all solution to go by – a tailored approach is always best.

'I’d start by working out how long your floor takes to warm up. That’s really what your schedule needs to be based around,' advises Martyn Fowler. 'If you get up at 7am and the floor takes two hours to get the room comfortable, have it come on around 5am. Then you can start bringing the temperature down before you go to bed because the floor will carry on giving off heat for a while. It takes a bit of trial and error at first, but after a few days you normally get a good feel for how your floor behaves.'

Ben Gallizzi agrees that the starting point when devising an efficient schedule should be your routine. 'There isn’t a single schedule that will work for every household, as it will depend on the type of system, the room and when the space is being used. However, it’s worth programming underfloor heating to come on ahead of the times you normally need the room to be warm. This can help save energy and avoid unnecessarily running the system when the room is empty, while still allowing enough time for it to reach a comfortable temperature.'

What is the most efficient way to use underfloor heating?

If you are still feeling a little unsure of the best way to use your underfloor heating to ensure you are getting the most out of it, Martyn Fowler has some words of advice. 'I’d keep it as low and steady as you can while still being comfortable. You shouldn’t need to make the floor really hot. If it’s a wet system, you also want to keep the water temperature as low as the house allows. That’s where underfloor heating can work really efficiently, particularly with a heat pump. And use the different zones if you have them. There’s no point keeping a guest bedroom as warm as the living room if nobody is in there.'

'Leaving underfloor heating on low all day shouldn’t automatically be assumed to be the cheapest option,' adds Ben Gallizzi. 'Running costs will depend on many factors, including the type of system, the size of the area being heated and the energy source powering it.

'Whatever type of system you have, using heating controls and a timer is important,' continues Ben. 'Rather than simply leaving the heating running continuously, you should aim to heat your home around your daily routine and only when warmth is actually needed.'

What is the best way to use underfloor heating with a heat pump?

Heat pumps can be one of the most efficient ways to heat a house – if you have one, or are considering installing one, finding out how to use it alongside your underfloor heating should be top of your to-do list.

'With a heat-pump UFH gets more interesting,' picks up Simon Bones. 'First, you can typically run a heat-pump with UFH at a lower flow-temperature than if you just had radiators (making the heat pump more efficient), so that’s a good thing.

'Secondly, most heat-pumps are sized close to the needs of the property so, particularly in the depths of winter, don’t let the temperature drop too much as the heat pump will otherwise be working flat out to get it to temperature – a 5 degree drop or less is probably what you want,' continues Simon.

'Also, if you use a time-of-use tariff then the time of day will have a big impact: if you’re on an overnight EV tariff, for instance, you may want to heat more in that window and, if you have a super-peak period, you may want to turn off the UFH during that time.'

FAQs

What temperature should you leave underfloor heating on at?

When it comes to the actual temperature to set you underfloor heating at, there is once again no magic number, although there are some guidelines worth considering.

'I’d normally start somewhere around 18°C to 21°C for the room and see how that feels,' advises Martyn Fowler. 'There isn’t one perfect number for everybody.

'If you're looking to find the right bedroom temperature to sIeep, you can bring that down a few degrees rather than switching everything off,' adds Martyn. 'And don’t worry if the floor doesn’t feel really warm under your feet. That’s actually quite normal.'

Once you have worked out the best schedule for your heating, make sure you familiarise yourself with the most common underfloor heating mistakes – it could save you a considerable amount of money on your heating bills and prevent any damage to your flooring.