Talk to me about underfloor heating?

Soldato
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Surprised I couldn't find much talk about it on here.

Total noob but what is the general consensus? For a small terraced house what would the outlay be for doing it throughout the ground floor? Would it actually make sense to do ground floor and not upstairs*? Electric or water? Does it work well with tiles? Does it cost more/less on your bills than radiators? Can you use both types in conjunction with radiators (period home, would like period radiators for aesthetics in certain places)

*Surely if you have electric underfloor downstairs and radiators upstairs you're paying 'twice' for heating your home? :confused:
 
Soldato
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I think underfloor heating always seems to be a bit of a fad. It always appeals and seems great, but after some time the appeal wears off and people tend to stick to traditional heating methods. YMMV!
 
Soldato
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I think underfloor heating always seems to be a bit of a fad. It always appeals and seems great, but after some time the appeal wears off and people tend to stick to traditional heating methods. YMMV!

i remember first walking on it in a new house back in the early 90`s and thinking how lovely it was to walk on barefoot
and quite a few people were talking about it back then so i dont think its a fad as such because its still around now.
I think it was an expensive faf to do that put most people off.

Im probably wrong though, im no builder
 

D3K

D3K

Soldato
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It’s a no brainer if you have the slightest interest and are happy to spend. Your boiler will operate with 35c water instead of 65. Uniform heat. No radiators acting as obstacles for your room layout.
I haven’t done it myself yet, but looked into it.

upstairs isn’t necessary but can be done. Main argument for doing so is for consistency of heaters I.e removing rads again, otherwise you have to work out a compromise with the temperatures. Electric rads upstairs would solve that.

you can do downstairs yourself with a machine to drill winding slots into concrete, then lay the pipe, and only call in the experts to finish it off and certify.
 
Soldato
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I have electric underfloor heating in just one room.

Our living room is north facing, large room, 2 large windows and a tiny radiator on the opposite side of the room to the windows.

We wanted to put hard floor over carpet but it's cold in this room anyway, so decided to put UFH in.

It's great for this room, runs on a 3kw ring and we can operate it separately to the main central heating so we can heat this room up without having to heat up the whole house, which is maybe? more energy efficient?

It is expensive to run though for what it is, I definitely wouldn't use electric UFH in your whole house to replace central heating.
 
Soldato
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Wet systems are totally the way to go, electric are ok for a single bathroom but the running costs are far higher. They're pretty efficient and pair really well with the greener heating methods like an air source heat pump as they require lower temps.

The problem you can get is if you can't have it upstairs as well, the downstairs underfloor will needs 35c and if you have rads upstairs will ideally need 65c. So you'd either need to swap out all upstairs rads for bigger volume ones or try and put wet underfloor in there which seems like a bit of a nightmare, underfloor heating doesn't really pair well with carpets either as you'd be essentially insulating the heat in the floor with the carpet and underlay.

I personally don't like it as i don't like the feeling of the floor being warm everywhere but i get that a lot of people like that, it is a huge undertaking to retrofit though, not sure how it works with suspended floors either or if that's even possible with a wet system.
 
Soldato
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It’s a no brainer if you have the slightest interest and are happy to spend. Your boiler will operate with 35c water instead of 65. Uniform heat. No radiators acting as obstacles for your room layout.
I haven’t done it myself yet, but looked into it.

upstairs isn’t necessary but can be done. Main argument for doing so is for consistency of heaters I.e removing rads again, otherwise you have to work out a compromise with the temperatures. Electric rads upstairs would solve that.

you can do downstairs yourself with a machine to drill winding slots into concrete, then lay the pipe, and only call in the experts to finish it off and certify.

Yup. Using underfloor heating would also enable to use a heat pump, whereas they don't really work for radiators. UFH is great for homes as well because you have very low occupancy levels i.e. very little heat being radiated by people. That means you don't need a fast reacting heating system, which UFH certianly is not.

If you do UFH, you need to make sure that your flow rate is low enough that you do get the proper return temperature that it is designed to, maximising the delta T across the circuit. Also, the way they lay it is important. The pattern should be like a snail shell isntead of laying it out in rows. This is because as you deposit the heat across the floor, if it's laid in a row you'll have all the heat being deposited on one side of the room. The snail shell pattern avoids this problem, giving you even distribution.

That feeling of a warm floor by the way isn't actually what you need - that's excess heat i.e. flow temperature is too high. The floor shouldn't be cold, but nor should it be hot.
 
Soldato
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Thanks guys, useful opinions!
The general consensus is wet systems are far superior.
I can imagine. Much harder to install though but I guess they work better with central heating?
It is expensive to run though for what it is, I definitely wouldn't use electric UFH in your whole house to replace central heating.
electric are ok for a single bathroom but the running costs are far higher.
Yeah (answering both here). I was thinking about this last night. Any sort of electric heater is very expensive to run so I can't imagine how much a whole UFH system would cost. Any ideas for running costs? We're pretty tight with the heating as it is. I can't imagine we'd be free and easy with the underfloor heating all the time through winter if it costs even more to run.

Main areas we were thinking of is the downstairs hallway (hopefully tiled) and then possibly kitchen/dining room (wooden floor). But I think you've all done enough already to make me think it's not worth it :p Like food shopping when hungry, perhaps we shouldn't be making decisions for heating when it's freezing!
 

D3K

D3K

Soldato
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Thanks guys, useful opinions!
I can imagine. Much harder to install though but I guess they work better with central heating?


Yeah (answering both here). I was thinking about this last night. Any sort of electric heater is very expensive to run so I can't imagine how much a whole UFH system would cost. Any ideas for running costs? We're pretty tight with the heating as it is. I can't imagine we'd be free and easy with the underfloor heating all the time through winter if it costs even more to run.

Main areas we were thinking of is the downstairs hallway (hopefully tiled) and then possibly kitchen/dining room (wooden floor). But I think you've all done enough already to make me think it's not worth it :p Like food shopping when hungry, perhaps we shouldn't be making decisions for heating when it's freezing!
Electric UFH is quick and easy. It can be laid under carpet, and then just plugged in. Running costs are your problem.
 
Soldato
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Thanks guys, useful opinions!
I can imagine. Much harder to install though but I guess they work better with central heating?


Yeah (answering both here). I was thinking about this last night. Any sort of electric heater is very expensive to run so I can't imagine how much a whole UFH system would cost. Any ideas for running costs? We're pretty tight with the heating as it is. I can't imagine we'd be free and easy with the underfloor heating all the time through winter if it costs even more to run.

Main areas we were thinking of is the downstairs hallway (hopefully tiled) and then possibly kitchen/dining room (wooden floor). But I think you've all done enough already to make me think it's not worth it :p Like food shopping when hungry, perhaps we shouldn't be making decisions for heating when it's freezing!

I think the commonly banded around figures are roughly 4x the cost to run electric compared to gas/other wet heating systems. That's where things like heat pumps comes in as they're 400-500% efficient so it brides the gap back to gas type heating costs.

So again fine for a bathroom you'll have it on for 30 minutes a day in a fairly small area but you wouldn't want to heat your house that way.
 
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Soldato
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Electric UFH is quick and easy. It can be laid under carpet, and then just plugged in. Running costs are your problem.

It was a bit more involved for our system, we had insulation boards laid, the UFH system laid down then liquid floor screed over that. That was done by an electrician.

It is wired on its own ring from the main RCD, with a thermostat on the wall to control it.

We had had karndean put over by floor fitters.

It did raise the floor a bit, maybe 20mm but was preferable to having to rip up the existing underfloor which were like chipboard (whatever it is) over more insulation then concrete as our house is only about 20 years old.
 
Soldato
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We had wet UFH throughout in the house we’ve just sold.

Absolutely loved it, would definitely recommend it. However, that place was built with UFH as part of the original plans.
 
Soldato
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We have a mixture in our house. We have gas central heating with normal rads, but downstairs toilet is under floor electric with tiles. The kitchen/diner is a good sized room and for that we have under floor wet. This was all installed before we bought the house.

The downstairs toilet for some reason in our house is proper cold. I think it's because it's exposed with minimal insulation. I don't know why they didn't put a normal radiator in there but it is quite small and the asthetic is nicer without one. Maybe the pipe run had complications. Maybe it never came with one originally. Anyway... No idea what kind of electric pad it is under the tiles or what rating but basically we have to turn it on and Max the temp out, then after about two hours the room has noticeably warmed and the floor can be felt warm under foot but very much in the middle. The tiles will still be cold at edges and near toilet.

I can only imagine how much the electric would cost to keep that warm all the time so we tend to turn it on for when guests come round and just live with it being fekin cold. Lol. I don't know how to measure the usage because it's not terminated at a plug and is obviously hard wired to a fused switch and we don't have a smart meter usage thing. It has its own controller in the hall which you can set to use air or floor temp to measure.

The boiler is fairly modern (not combi) and the house warms nice. No tank in the loft as it's a loft conversion.

The kitchen underfloor is a wet system and runs off the same main boiler. We have no issues with running it on its own or simultaneously with the main house radiator heating. There is a manifold behind one of the kitchen cupboards where the system gets fed and there is a small pump in there like you would see in an airing cupboard. It's inaudible. It has its own digital thermostat and controller in the kitchen and its basic and a bit rubbish. I should update it.

The kitchen underfloor shocked me. I read that they should be left on all day and stories of people having to turn them on hours before hand to reach temp. Well...ours works ridiculously well. If I turn it on the room is noticeably warmer within 30 mins. The floor gets toasty under foot which is nice. Everyone loves it and comments on it. It's not as controllable as I want it currently but that's because the controller only seems to be able to do on or off lol. So I need to sort that but I love the system and it heats the whole room very evenly with no ugly rads.
 
Associate
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doing it in my house at the moment, wet UFH downstairs, rads upstairs. the boiler runs at the normal temp for rads( unlike what someone above says) and the blending valve on the manifold controls the underfloor temp. just put the pipes in for the lounge which is a joisted floor, insulated and 25/30 mm screed over the pipes which will have an engineered oak floor over it. my plumber mate who is fitting it did the same at his house but put carpets over it, says it works well as long as your carefull with carpet and underlay choice. fast reacting with such a thin screed but also cools quicker. i think its a better option than spreader plates. kitchen and second lounge are solid floors so after i've dug them up will be in a thicker screed.
 
Man of Honour
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Our downstairs has it (gas heated):

Pros -
- the floor is lovely and warm
- a really even heat in the rooms
- no radiators, just gives a cleaner look and more space

Cons
- takes ages to heat up and cool down if say it’s not been off if you’ve been away or if it goes too far above the thermostat
- I can only imagine it being a nightmare if it goes wrong

Given the choice I’d go for radiators.
 
Soldato
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We stayed in a nice recently-built villa/lodge/bungalow on Skye which had underfloor heating throughout. It was zoned so each room had its own thermostat and it worked very well.

I'd definitely be looking at it if I was building from the ground up. Radiators take up space and in my opinion don't look great.
 
Associate
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We got our upstairs bathroom/wc knocked into one and I got electric underfloor heating installed at the same time. (There was also a traditional wet towel radiator.) I really like it. Thought it was the ideal opportunity to have it done. And might add a little 'wow' factor when we come to sell. After a few days of using it though, we soon realised it's far too expensive to run and no longer use it. If I recall, it worked out about 10-15p per hour, whilst running. I might turn it on at Christmas though, because it is very nice. :)
 
Soldato
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Does it have any pros Vs a radiator system designed to run at super low temps? Only one I can think of is losing the radiators on the walls. But with underfloor I'd have to have the floor altered is it even possible with suspended floors?
 
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