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Would you replace your radiators with underfloor heating?

Underfloor heating

Autumn is upon us and it’s hard to avoid looking towards the colder months and thinking about staying warm. Is underfloor heating the key to a cosy winter? Is it worth the cost and upheaval?

I’m a bit of a gloomy guts when it gets to this time of the year. Even the occasional sunny day can’t distract me from the fact that it’s getting dark earlier and the countdown to winter has begun. I can’t help my mind from being drawn to thoughts of chilly evenings and the annual realisation that I don’t have enough jumpers.

Yes, I’m already thinking about winter and wondering how cold it will get this year. Last year I managed to avoid switching my heating on until well into November, and I wonder if I can push it to December this year. I’m lucky though, my home is well-insulated and easy to warm up.

The building I live in is only a few years old and seems to have been built with energy efficiency in mind. Underfloor heating is standard in each of the well-insulated, double-glazed flats. I only recently realised that I have an Economy 7 electricity meter too, but I’m not sure how practical that is for me. I usually only have my heating on in the morning and evening. And it’s a small flat, so using my washing machine at night wouldn’t be ideal.

Is underfloor heating for you?

My rented flat is rather poky. If it wasn’t for the underfloor heating, I would have struggled to find a home for my modest amount of furniture. With no radiators to get in my way, I was able to squeeze in my bookshelves and drawers with the minimum of fuss.

My heating system is electric and seems fairly energy efficient. The most efficient underfloor heating systems benefit from heat pumps to draw warmth from the ground or the air. Unfortunately, a heat pump doesn’t appear to have been a practical option for my block of flats.

Are you tempted by the idea of underfloor heating for your home? If so, now is the best time to get it installed.

Water heating systems are complex to install, so you’ll need a professional engineer to fit them. Electric underfloor heating is less expensive to fit and there are some kits that a keen DIY enthusiast could tackle. You’ll still need a qualified electrician to connect your system to the mains, however. I was lucky to move into a home where the hard work had already been done.

Heart-warming radiators

I must confess, occasionally there are moments when I miss radiators. When I had the heating on in my previous flat, it was handy to be able to dry clothes on my nice, warm radiators. I also miss being able to stand next to a warm radiator after a walk in the cold. Lying face down on my hardwood floor just isn’t as cosy.

Which heating system warms the cockles of your heart? Do you already have underfloor heating? Do you think it’s better for your energy bills?

Beth says:
9 October 2013

Our hall was once a Victorian school; it has large windows and a vaulted (insulated) ceiling so it tends to get cold in winter. Our present heating is ancient and we are planning to put in underfloor heating as we have a Kindergarten using the hall during the day and yoga and pilates classes in the evening so the heat is best at floor level. We have a small field so could use ground source although we are also considering air source, especially as we have no access to mains gas, plus there is a government incentive coming in next year.
Has anyone experience of underfloor heating in a community hall?

Would you replace your radiators with underfloor heating says:
10 October 2013

This is a perfect application for underfloor heating – no pipes or radiators taking up floor space or hot surfaces for toddlers to touch. Low grade heat (50C) is an ideal partner for a heat pump and underfloor heating application. Mind the field and hall will have to be closed during the installation. You can install underfloor heating on top of the existing floor using insulation and a metal deck. You would need to carefully consider the floor covering to reduce noise from the metal deck.

Well I disagree with this mornings perfection idea! One thing you normally get with Victorian property is excellent suspended floors and the idea of putting something on top which is less giving needs some thinking about.

During the night I was pondering the problem and my thoughts leapt to a wood-pellet boiler. This may be able to use the existing pipework and minimise expense.

On the expense front we are given no size or budget but it occurred to me that if the land area is big enough the sale or a very long lease of a building plot could realise a very large chunk of cash that could be allocated to the hall as a sinking fund once the work was done.

You can go for a wet system or possibly more flexibly a space heater such as Fabbri. This site here allows you to spec the size of burner needed.

Blast it. A return key hit and it was posted!! Furshuglinner website.

I have read about wood-pellet burners things but have no practical knowledge so a fair bit of research needed. One other thing is that if you wish to go the geothermal route then you can drill and install effectively vertical pipes into the ground …. useful if you sell off the land : )

Another couple of ideas are to install a heat exchanger so that your necessary ventilation requirement allows the incoming air to be heated by the stale air being extracted, and uncommon in the UK a reverse fan which is designed to throw the hot air in the upper part of the hall down to ground level. Probably not ideal for the badminton but otherwise ….

Beth , perhaps you could give dimensions and budget as without those it is hard to be realistic. Also a big concern for me might be I can get a certain ambient temperature but need boosting for small, elderly, child groups and would need another system. Basically I am saying the usage of the hall and times might show that an air heat system is more flexible than a wet system.

Fiona says:
10 October 2013

A word of warning: when friends of mine moved into one of the Nash Terraces in Regents Park the underfloor heating cracked up the antique furniture! This is about 50 years ago so perhaps systems are better now!

Dave says:
10 October 2013

One thing that condensing boiler makers don’t tell you is that they only achieve the headline efficiencies of 90%+ when operating at flow temperatures of below 60degrees. Above that, and at typical wet radiator older design specification of 80degrees (modern systems tend to work on 65degrees), they might only achieve the typical 75% efficiencies of the old boiler you just chucked out.

This makes underfloor or over-large radiators significantly more efficient because they run at lower temperatures. One way out of this is to fit a weather compensator, which automatically modulates the boiler flow temperatures down, and into the high efficiency area, on the many milder winter days.

Only problem is many installers haven’t got the time or the knowledge to set them up properly.

I’ve largely discounted wet and electric underfloor heating for my project. I’m intending on replacing all radiators and pipework and replacing decades old boiler (55% efficient max) for a 90%+ condensing one. So what you say has me concerned I won’t get the best efficiency I could possible achieve. I heard about Low Surface Temperature (LST) radiators as an alternative and something that’s compatible with heat pumps. Does anyone have views and pointers for those? Thanks.

I believe you will need to have very large LST rads to get sufficient heat. Check carefully – you lose a lot of wall space which may be ok in your design. Having put underfloor in with new condensing boiler, decent controls and a weather compensator unit I would not want to move anywhere without u/f heating again.

Would you replace your radiators with underfloor heating says:
10 October 2013

Low surface temperature radiators are used in hospitals and buildings where the occupants are under 5 years old or over 60. They are basically a natural convector or a radiator in a cabinet which is warm to the touch even if the water circulating is hot (80C)

Sure that’s the traditional place for them. There was a paragraph or two in a renovation magazine a few months ago about LSTs specifically designed for use with heat pumps – from http://www.jaga.co.uk/

Dave says:
10 October 2013

You can still make significant saving with an older radiator system designed for 80C operation. Remember, the 80C is only required on the coldest days – I reckon 10-20% of heating days. On milder days, a properly set up weather compensator will turn down the boiler flow temperature, significantly increasing its efficiency.

Obviously, replacing existing radiators on such a system with larger ones, or double panel instead of single, etc, would also allow the boiler to operate at even lower temperatures.

I worked in an office with underfloor heating downstairs and radiators upstairs (the two floors were open-plan so all heating should have circulated). Unfortunately working downstairs we were cold whenever the external door was opened and those of us seated at our desks had considerable feet/leg ache from the underfloor heating.

Bonnyby says:
13 October 2013

I had a conservatory made and fitted. It is small, 9 ft by 7 ft. I also had underfloor heating fitted in it.
My electric bill became dearer – now I have a fan heater and a plug attached that switches off after 1/2 an hour. Perfect!

Niki says:
26 October 2014

As we are intending to buy a newbuild house with airsource underfloor heating, I hoped to find some advice on the internet, but can’t find any. I fear that we should give up the idea as I have had a DVT and there is a history of pulmonary embolism in my family. I am 73 years old and would appreciate a reasoned opinion. I understand the floors would be heated to between 25 and 29 degrees centigrade.

Hi Niki, thanks for your comment. We have some information on underfloor heating, including pros and cons. Please follow this link to find it:

I am surprised at the figure for the floor as it sounds quite warm to me. I wonder if that is actually the temperature of the water through the system?

Depending on the floor material the transmission of the water temperature to the floor temperature will have some losses. However I am relying on memory of my 7.5 by 4 metre underfloor system heating tiles through screed. Always wonderfully warm to the bare feet.

The heat you are looking for in a lounge would be 21C ish and because the heat is always coming up from floor level it is really very good.

I think you need to discuss it with the builder/installer as to the detail such as output , brand of the machine and then have a browse of the Web. Overall though I would leap at a underfloor heating for my ground floor. Upstairs would be a luxury but probably not justifiable … : (

franklin says:
23 October 2015

about to have electric underfloor heating put in but are concerned about removing some rads. not all areas will have underfloor. bath rooms and hall. kitchen floor and hallway are planned as underfloor with standard rads being used in living room .conservatory and bedrooms. thus hoping to get best of both worlds with an overall heating via under floor and rads as fast response for cold weather snaps etc.
really unsure to remove rads in hall though..this is a main junction between rooms and not sure floor heating is enough as when door is opened to street etc heat loss is rapid . plus not sure about selling on later of needed ..will buyers prefer to see a rad or be happy with underfloor? our current thoughts are to have both in hallway and use have thermostatic control on rads to assist here with high heat levels changes e.g. guests .doors open etc.


Can anyone tell me their experience of using underfloor heating on insulated joisted floors (spreader plates etc) finished with engineered wood planks?
I am considering this for my living room, hallway etc but have been told this is no point because you don’t get the thermal mass effect you get when using UFH in solid concrete floors.
I really don’t want radiators because I want the wall space back. Hope you can help. I am struggling to find an article that talks about the relative efficiency of the different wet UFH systems.

Hi Joanne.
We did a self build house and installed a wet UFH system throughout powered by an oil boiler. It was made by a company called Robbens. You can google them up if interested. The ground floor is solid screed and the first floor similar to as you describe. It is a great system and thoroughly warms the bones of the house. The first floor runs at a higher water temp (60 degrees I think) than the ground floor (45?) due to the different construction but this is all set up for you on installation. All you need to do is set the room thermostat for the temp you want and leave it. We set the room temps we want and then leave the system on all the time and it’s electronic brain does the rest. There are radiators in the bathrooms to warm towels etc but underfloor as well so great when you get out of the bath a step on the warm tiled floor. It is quite a bit more complicated than radiators but I wouldn’t be put off. The only down side is the slow time it takes to make any difference to the temp and it’s no good coming in in the evening and switching it on as you won’t notice much heat until you go to bed. It is a bit quicker to react upstairs without the solid screed mass to heat up. That’s why we leave it on all the time which seems highly efficient and the best way to run it. The lack of radiators in the main rooms and the extra wall space for furniture is really noticeable. Give Robbens a call if you want to take it further. They were very helpful and even sent an engineer to the house to brief my plumber and electrician on how to instal the system.