Can Radiators and Underfloor Heating Work Together?

Image for radiators and underfloor heating working togetherIntro

This is another one of those questions that people ask when they are exploring the option of having underfloor heating fitted, and it’s a good one too.

After all, some people may just want a nice warm floor in their bathroom but not be all that bothered about having UFH throughout the rest of the property.

Another reason for this question is when someone already has a central heating system in place, they may be concerned about the costs and hassle of a complete switch from one system to another.

With these points in mind, let’s take a look and find out…

Can radiators and underfloor heating work together?

The answer to this question is yes, you can have both systems on one boiler.

It is possible to create zones in your home, where one part gets heated via the radiators and others warm up with underfloor heating. You can even have both in the same room if you wish.

However, how the two systems are configured largely depends upon whether you are planning to use wet or dry underfloor heating.

The options

In the case of wet underfloor heating systems, pipes are installed under the floor. These carry water (in some circumstances it may be a water/glycol mix, for instance when used in conjunction with a heat pump) that has been heated by your boiler around your home and through the pipes to heat the floor beneath your feet.

A dry system, on the other hand, runs on electricity which sends heat through the floor via mats or loose cables. Think of these as similar to the elements found inside an immersion heater or kettle. Electric underfloor heating can be installed without having to interfere with your central heating at all.

Cost

A wet system is more costly to install, but the running costs are less than that of the dry system. The cost of installation and the running costs are obviously something you will want to take into consideration.

Dry systems are also more likely to be used in renovation projects where there is insufficient space for installing a wet system. However, if you prefer a wet system it is sometimes possible to raise the floors to create the extra space needed to install the pipework, but you must take heed of the current building regulations before doing so.

Take a look at our articles on UFH running costs and comparing wet and dry underfloor heating for more info.

Combining radiators and dry underfloor heating systems

This is the better option if you only require UFH in a small area, such as a bathroom, as the radiators and the underfloor heating run completely separately.

It can be expensive to heat a whole house using electric underfloor heating so having radiators in the larger rooms is the way to go if you opt for dry UFH.

As you can probably imagine, using electric underfloor heating throughout the house is not all that energy efficient. If you really want UFH throughout you should give serious consideration to having a wet system installed.

Combining radiators and wet underfloor heating systems

Contrary to some people’s perceptions, it is possible to run both UFH and central heating radiators off of one boiler. You can keep independent control of each with the help of a zone valve which will keep energy usage down and, in turn, lower your running costs.

How a wet system works

Once the hot water from the boiler has flowed around the system, it then returns to the temperature sensor. The water may have cooled somewhat but, provided it is still warm enough, it will be recirculated through the underfloor heating pipes once more.

A sensor, which is fitted to the manifold, will detect a drop in temperature and this will prompt more hot water to be pumped into the system via a mixing valve. This will keep the heat in the floor at the desired temperature, while the radiators run separately.

Conclusion

As you can see, running both radiators and underfloor heating is entirely possible.

For a more efficient system, having separate zones is recommended. Some people opt to just have one floor (usually ground) with underfloor heating and the other floor/s just using radiators. This setup is perfect for those who use the lower floors more during the day and the upper floors (bedrooms) at night.

Whatever way you decide to install your underfloor heating, one thing is for certain – your feet will be glad that you did.

 

Let us know what you decided on. Leave a comment in the box below.

 

42 Comments

  1. Michael Fizpatrick

    Hi i have a wet under floor heating system on ground and first floor, ground floor is fine. The first floor is not working, the ceiling on the ground floor is decorative, exposed beams etc. I am wondering if i can link in aluminium radiators to the existing first floor loops. I think this against the cost and disruption of the plastering makes me consider the radiators as a cheaper less disruptive solution.

    • Underfloor Heating Expert

      Hi Michael,

      While in theory it would appear possible, without seeing the setup for ourselves we’re always loathed to give definitive advice on individual systems. In this instance, troubleshooting why the UFH is no longer working would be our first recommendation.

  2. Veronika Dalton

    I’m considering making the switch from electric to wet underfloor heating. I hadn’t considered the cost savings, and would have assumed that a wet system would have taken more energy to operate. Up here in Alberta, I don’t think I’ll be able to survive another winter with tile floors with my electric system. It hasn’t been reliable the last two winters and we have had a few repairmen come out to look at it, but I may do a whole new installation now, rather than fighting with the existing electric heating. Thank you for your insights about the benefits of a wet system.

    • Underfloor Heating Expert

      Hi Veronika,

      No problem at all, and thanks for taking the time to comment – we really appreciate it.

  3. Marcos

    Hi can it run the same temperature as rads?
    Eould it be possible just tp connect to a radiator and the pipes underfloor will get hot?

    • Underfloor Heating Expert

      Hi Marcos,

      No. Radiators run at a far higher temperature than underfloor heating does, therefore you’d need to separate your settings with a zone valve and independent controls. Hope this helps.

  4. Jonny

    My question is: can a wet system be run in the same room as piped radiators, assuming all the necessary pumps & zone valves are installed to achieve separate flows to each……..how does the stat control work between each. Normally you would have a room stat for the ufh picking up the ambient room temp and then a TRV on each radiator (inc. a room stat either in the room or on landing). Surely the if the ufh stat picks up heat from the radiator it will switch off the ufh zone before reaching the required temp for the ugh to fire up??

    • Underfloor Heating Expert

      Hi Jonny,

      We would advise against having both a wet UFH system and piped radiators in the same room for that very reason. The basis of the article is that you can indeed run both together, but to separate rooms or zones as mentioned in the conclusion.

      For dry systems, both can, and in some cases should, be used in the same room together.

      Hope this helps.

      • Dario

        Hello, I’m having a similar issue. We installed wet UFH on the ground floor dividing it into two zones, one with its own thermostat. The ground floor also has 3 radiators powered by the same boiler + Hive thermostat. Our builder installed a separate valve that, in theory, would allow the UFH and central heating to run separately. However, when we tried to run them both together we noticed two things: 1) the UFH never seemed to heat up properly; 2) when the UFH aw on, one of the 3 radiators suddenly became colder. With the UFH off, the same radiator was working perfectly. Any thoughts? Thanks.

      • Underfloor Heating Expert

        Hi Dario,

        That doesn’t sound right. I would get someone round to take a look at the system, something is amiss there. Sorry I can’t give you a better, more accurate answer, but it’s one of those situations where you really need to be onsite to run tests in order to find the root cause of the problem. Hope you get it sorted.

  5. Natasha Burnett

    Hi there,

    We have had wet ufh installed in our new extension. What I can’t get an answer about is how the timer will work for the rest of the house which has radiators. I want my radiator to come on twice a day. Am and PM but want the ufh on all the time to be effective and adjust manually with thermostat. Can this work? My builder seems to suggest that the boiler needs to be set to On rather than timed setting and I adjust the radiator heating with the thermostat. But I don’t want the heating to kick in in the middle of the night or day when we aren’t here and the temperature drops. He says they work independently but can’t explain how!
    Thanks.

    • Underfloor Heating Expert

      Hi Natasha,

      As the article mentions, the UFH and radiators should be separated – commonly referred to as zones – upon installation. This will allow you to control each independently. your builder is correct in saying that the boiler will have to be on to supply hot water to the UFH at all times, but it will run at a very low temperature compared to what radiators need to be effective. With two different zones you can set one to be on constantly (UFH) and the other to come on when you wish via that zone valve’s timer. Hope this helps.

  6. Dan

    Hi,
    I have just renovated my kitchen. I fitted wet underfloor heating, with a recirculating thermostatic manifold. At present all of my heating is on one zone (existing radiators and new UFH).
    I realise that I need to zone the system so that I can have the rads on when I need heat in the other rooms and the UFH on for longer periods.
    I understand that this will consist of zone valves. I want to understand how to control the valves and the boiler.I would like a thermostat on both zones so that either can call for heat if required. Also I would like both zones to be on a programmable timer. Finally my UFH manifod has a pump and I would like to control this so that the pump is only running when UFH is turned on.
    Is there an off the shelf product that can control both zones and my boiler. If so could you recommend any specific products.

    • Underfloor Heating Expert

      Hi Dan,

      This can be done, but you’d need several items rather than a single off the shelf product. Your best bet is to give a decent local plumber a call if you are unsure of how to go about it. Alternatively, if you really want to have a go at it yourself, this article explains zoning pretty comprehensively.

      Cheers

      • Dan

        Thanks, I have a plumber (my brother), but he hasn’t done much underfloor heating before.

  7. ECM

    Hi
    What setting should my combi boiler be set to (‘timer’ or ‘on’) in order to run the radiators (at separate times of the day), and keep the under floor heating on for the majority of the time? I don’t want the radiators to be on all of the time. In fact some of the time I just want the UFH to be on, and none of the radiators.

    • Underfloor Heating Expert

      Hi Emma,

      Whether the boiler is on by the timer or by manually being in the on position, it is still ‘on’ and will push heat in both directions. In order to achieve what you want, you need to have separate zones with different controls for each so that you can switch off certain areas (radiators) while the other (UFH) remains on.

      Hope this helps.

  8. Neil

    I want to put dry UFH in my bathroom, but all the kits come with their own control panel. How can I install the dry system so that it comes on and off with the normal gas central heating? I don’t mind if there are separate thermostats, but i don’t want to have to turn both on and off each time.

    • Underfloor Heating Expert

      Hi neil,

      You’d need to look out for a control unit that’s capable of handling both and run the electric ufh from that. It will likely be set up as zones, but you can programme it once and forget it if a timed on/off is all you’re looking for.

  9. Natasha

    Hi there
    I’m moved into a house with underfloor heating downstairs and rads upstairs, I’ve got two thermostats which were left labelled up and down. When I put the downstairs underfloor heating on the rads upstairs all come on and stay on. I’m finding it takes forever for downstairs to heat up with just the underfloor and the temp on the thermostat doesn’t seam to go above 22 even after 4 hours or more. Why is upstairs coming on and can I turn the rads off without turning all the valves on and off all the time.

    • Underfloor Heating Expert

      Hi Natasha,

      Without looking at your particular system first hand it’s difficult to give an accurate diagnosis of the problem. The best advice I can give is to get a local plumber with UFH knowledge round to take a look.

  10. Andrew

    Hi,

    I am in the process of renewing the concrete floor downstairs in my house and i would like to install underfloor heating at the same time. I have read conflicting advice as whether UFH is a good idea in older properties (1948 house). Due to this i was thinking of leaving the downstairs radiators on the walls and part of the heating system. I appreciate what you have said with regards to temp control issues running both. Is it possible to shut the UFH circuit off when i want to run up and down rads in the house or vice versa, shut the downstairs rads off and open up UFH circuit. Or would this lead to problems?

    • Underfloor Heating Expert

      Hi Andrew,

      Providing your system is properly set up with separate zones, this shouldn’t cause you any issues.

  11. Sylvia ODonoghue

    Hi We have just had a wet underfloor heating system installed to our kitchen / sitting area. We are having one problem both the competent plumber and heating supplier cannot solve. We have one zone for the kitchen area of 11 sq metre and 2 nd zone 16 sq metres . All appears to be working correctly ,but the system has difficulty reaching temperature for instance .we leave it on permantly , overnight on 20 degrees. Then from 6 am set to 21 degrees .which will take over 3 hours for 1 degree. All day it is set 21 degrees. Then 2.30 pm to 22 degrees. It normally shuts of at 21 degrees about 9.30 am and remains around 22 degrees all day, which is perfect. The problem is because of the long warm up time it will tend to feel cold between 4 to 5 pm. It will take till 7 or 8 pm to reach its temperature . The installation was carried out in accordance
    with the manufacturers requirements, the system used was pipes set into an insulation board. Set 150 mil apart. The concrete screed was the
    approved specialised for underfloor heating, the temperature on the manifold is set just under 50 . above the recommended 45 in the manuals as per suppliers suggestion . In the evening our feet start to burn as the floor is too hot. The floor finish tiles. The water temperature on the boiler is set well above the 50 degrees to 80 . The installer cannot understand why we have this problem. Are we missing something? It is perfect morning and daytime , evenings once it reaches temperature perfect. The temperature is held on the floor for hours and we only require an increase in temperature of 2 degrees and it takes 5 hours . Your help appreciated .

    is tiled

    • Underfloor Heating Expert

      Hi Sylvia,

      Not sure what’s going on here. You say that the floor isn’t heating up quick enough and yet, when it does reach top temperature, it is burning your feet. This clearly should not be happening, so there must be a fault somewhere along the line, either with the installation or the way that the settings are being programmed.

      You shouldn’t need to run your system so hot in order to achieve a comfortable level of heating, so I would advise you to get someone round to take a look at your system and how you are using it. I know you mentioned that you have a plumber who’s baffled by it, but it’ll be worth getting a proper UFH installer round to see if they can troubleshoot the issue for you.

      Sorry I couldn’t give you a more definitive answer.

  12. Natasha

    Hi there. Couple of questions. Recently I discovered that the thermostat for our ufh is reading about 2-3 degrees sometimes 5or 6 degrees cooler. I bought a thermometer which is reading in the 20s normally but the ufh thermostat barely gets above 20. It is on a the shared wall with my neighbours. We have ufh in the new extension and old kitchen and radiators throughout the rest of the house. The room was set at 21 degrees but I find I am now constantly changing it up and down as it can get too hot, Then it is too cold. In addition to this when the weather was milder the boiler used to make a terrible whirring noise when the ufh clicked on.
    This doesn’t seem to have happened since the temperature has dropped. My builder has been useless and of course it never makes a noise when he comes round as the doors are usually open and the temperature has dropped. I wonder if the whirring noise is related to temperature problem? I am sure I need to move the thermostat but wonder how easy this is to simply replace it with a wireless one and if I could do it myself? We have a valliant eco combi. Thank you!

    • Underfloor Heating Expert

      Hi Natasha,

      Sorry to hear that you’re having trouble with your builder, these things can be very stressful.

      For the boiler issue, is it new or has it been in place for a while? If it’s an old one, I’d recommend getting someone in to run a full service on it. If it’s new, contact Valliant and tell them what’s happening. You should be under warranty and they will be able to advise you further.

      As for the thermostat, where it’s positioned isn’t really a concern, it’s where you have the probe that matters. Do you know whereabouts it sits? Again, it’s hard to comment on what the problem might be without being there to run tests, so I would advise you to contact a reputable underfloor heating engineer in your local area. They will be able to diagnose any problems you might have and give you the specific help you need to get your UFH running properly.

      Sorry I can’t give you a quick fix, it really needs further investigation.

  13. Adam

    Silly question but is it possible to simply remove a rad and plumb in the underfloor heating in to the same feed? I only ask as running a separate feed would be difficult to say the least. The entire property is fed by a pellet burner and whilst the rads are good i have one room that would really benefit from not having rads in there as it is a very old house (circa 1604) and rads tend to spoil the asthetics.

    • Underfloor Heating Expert

      Hi Adam,

      Not at all silly! It can be done, but it largely depends on the existing set up you have. I would get an installer round to take a look, they will be able to check everything out for you and advise you better than I can without seeing your property.

  14. Rich

    Hi. I have just finished doing a ground floor extension. My builder convinced me to put underfloor heating pipes in the extension screened area. However rather than fitting expensive pumps and manifolds he connected it up alongside one of the radiators with its own thermostatic valve. I understand from reading all your comments that the very hot water from the radiator might damage the screed. But if I keep the thermostat set quite low should that then be ok? What happens to the screed? How long does this take before you notice the damage? Your feedback would be much appreciated. Regards. Rich

    • Underfloor Heating Expert

      Hi Rich,

      The problem with some thermostatic valves is that you really don’t have the control you need in order to get the temperature just right. For example, those with settings 1,2,3,4 and 5 – what do those numbers actually mean? What exactly is the difference between, say, 2 and 4 in terms of water flow temperature? Keeping the settings low ‘should’ be okay, but you’re relying on the valve without really knowing what’s going on beneath your flooring.

      In terms of damage to the screed, if run too hot, it will expand and contract too much and eventually crack. This will lead to the flooring that has been laid above it to warp and you’ll notice bumps and uneven spots.

      As ever, this is just an opinion and not advice. You could run on TRVs (thermostatic radiator valves) for years without issue, but then again you may not. I haven’t seen your set up, nor have I seen the materials used by your builder, so I’m just commenting on what you have said. In no way am I saying your builder is wrong, but you will need to keep check on the flooring to ensure that it’s not getting hotter than it should be. If in doubt, turn the UFH right down – especially if you have laid expensive flooring on top.

  15. Chris newth

    Hi, I had a new central hearing system installed a year ago (had a nest thermostat placed in the hsllway) and now in doing some renovation works to the downstairs and where in changing the flooring am toying with the idea of installing dry underfloor heating to the dining room / kitchen and hallway. Where I have rads and the thermostat in these locations, what is the best thing to do so the two systems can work in harmony? Move the thermostat upstairs for the central heating system?

    • Underfloor Heating Expert

      Hi Chris,

      Firstly, apologies for not getting back to you sooner.

      If you are looking to do away with regular central heating downstairs and rely solely on UFH, then yes you will need to remove the old thermostats from this part of the home as they will be redundant. Most dry UFH kits (see here if you have laminate flooring) come with their own thermostats, so you can replace the ones you remove with these. As far as I’m aware, Nest thermostats are not currently compatible with high voltage heating systems, of which electric underfloor heating is one.

      Having the central heating thermostat located where the radiators are being used will give you greater control, but it’s important to find the correct spot. This article from Nest will help you with that – https://nest.com/uk/support/article/Where-s-the-best-spot-to-install-my-Nest-Learning-Thermostat

      Hope this helps!

  16. Vicky

    Hello, I’m planning on wet underfloor heating in new extension, but our very old house rattles like crazy with all the pipes when our normal central heating in on. Can the new wet underfloor run separately without the rest of the pipes rattling? Any feedback would be very welcome!

    • Underfloor Heating Expert

      Hi Vicky,

      While you can certainly run the underfloor heating separately, you will still need to heat the rest of your home so the rattling will probably persist. Speak to your plumber about the problem that you are having as they may well be able to inspect and diagnose the problem when on site.

      • Vicky

        Thanks so much for your reply. I’m assuming that yes, when all other radiators are on the rattling of ancient pipes will continue (which is fine) but that when we have the underfloor heating on permanently over the winter (separate to house rads which will only be on at timed periods and not over night) that this will not cause rattling in itself? Assuming there will be a direct feed from the boiler to the new floor, by-passing the rest of the heating system? Thanks in advance!

      • Underfloor Heating Expert

        Hi Vicky,

        Banging, rattling and other weird and wonderful noises usually come with age (or poor installation), so you should be just fine providing you use a reputable plumber/installer. Make sure you highlight this issue to whoever fits the UFH and make a point of the fact that you’d like to avoid this happening with your new installation. That way, should you encounter problems, you can call them back to fix the issue, but you really should be fine with new pipework and a zoned system.

        Hope this helps!

  17. boriskas

    CoGood article, thank you, a lot of useful information, I will do so.mment

  18. Annika Larson

    My husband and I are looking at having a heating system installed under the tile in our home. We have a central heating system, and we are wondering about the cost and hassle of switching from one system to another. I didn’t realize that the dry system could be installed without having to interfere with your central heating at all, as you said. Thanks for sharing!

  19. mike wallace

    We have wet underfloor heating in a other part of a very old house, I watched how the plumber installed the system and was wondering, Because we cannot open up the floor Is it possible to run Radiators using the same
    Type of valve and control manafold that he used on our other part of the house, The new system uses flash water heaters with a mix of glycol and water, it is a closed system

  20. Clive Hodgetts

    We have a boiler supplying radiators throughout the house and a hot water tank. In a recent extension we have wet ufh running on a separate zone off the same boiler. So far, so good ! Despite my usual philosophy of Keep It Simple Stupid, we are now planning a new kitchen and wondering if we can install wet ufh as another, separate, zone connected to the main supply / return at the boiler. That would make four zones. We have been told by the plumber that this would work ! Is there anything we / the plumber particularly need to look out for in the design, filling, commissioning and use ?

  21. Clive Hodgetts

    We have been told that ufh will have sufficient output to heat our kitchen but I’m concerned that with only about 9m2 of useable floor area (because of the kitchen units around three sides) in a 16m2 room and with a 3m high ceiling even with good insulation this may not be enough. If the supplier and installer do eventually persuade me that it will be sufficient but this winter I find that it is not, will I be able to run the ufh to maintain a base temperature and then top up when we need it with a radiator ? Would I do this by setting the ufh to max and then set the radiator to the desired room temperature (as long as the ufh temp setting is higher than the radiator)?

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