Is underfloor heating worth it?

[Sorbustree123]

Bought a house with an old back boiler that's not safe to use so overhauling the central heating system with a new combi boiler, pipework and radiators, with all floors coming up to achieve this. However, a few people have now mentioned underfloor heating to me, which does sound great, but I have no idea where to start. Is it a lot more complex to install? How does the cost compare? Do you need a specialist? And can you have a mix of underfloor heating and radiators? Thanks!

We are just about to start an extension and reconfiguring most of our downstairs.

We had originally planned for ufh in the whole downstairs but we've abandoned the idea.

The reason is that in our existing house we only have about 70mm between the floor and the concrete slab underneath. That limits the options of systems and essentially doubled the cost.

In the extension (60sqm) the quotes were between 3-5k. In the rest of the house (50sqm) we were looking at 8k and even then we would lose some head height as the floor levels increased which qe can't afford to do (old mill, beams, low ceiling height downstairs).

Worth pointing out that is for wet UFH, electric just uses mats which take up no space but i have heard are obscenely expensive to run.

We were also advised by our plumber who is in the middle of his own old farmhouse renovation that with the drafts etc in the old part of the house that the UFH would have to be on all the time and just wouldn't be as efficient as radiators especially when you consider cost to install. (Whereas our extension is so well insulated that it would survive an adventure to the North Pole without a coat).

So we are having a mix of radiators and UFH but its all run off the same boiler. I have read that a good plumber will set your system up so the water runs through the radiators first when its at its hottest then to the UFH which geenerally doesn't require such hot water.

We already have a wireless system to control our exiating radiators called Tado. The idea is the same as Nest (which you've probably seen advertised) but Tado also has individual radiator thermostats. Its a bit of an expense to install. £50 per radiator thermostat and another £200 ish depending on what your setup is for hot water etc. But you can quite easily DIY fit them! (Loads of videos and instructions online and the radiator thermostats are so easy my kids can do them).

What this means is that we can control each radiator/room on a different schedule and that the radiator will switch off if that room reaches the set temperature even if the boiler is still required to keep the other rooms to temps. This will be critical for us as we will spend the majority of our time in the extension and I don't want to have to heat the rest of the house when we aren't using it. But equally don't want to turn off the radiators elsewhere and be freezing in the bedrooms.

Hope that helps. We are in the thick of planning at the moment and to say I'm an overthinker is an understatement!

I would say get a few quotes as ours varied widely. Equally though make sure those quotes are from reputable/recommended plumbers, not an area you want to play with cowboys!

Oh and we have an oil boiler (which we're replacing but only because its in the way).

We have wet in a new extension (very large tiled open plan space) and electric in bathrooms, very beautiful radiators everywhere else.

I absolutely love the wet system and nearly didn't have it but the costs have come down a lot over the years. However, we were putting in an entirely new concrete base etc. so no digging up the existing floor.

The electric in the bathroom is lovely but really not necessary (and the controls are horribly complicated) - you can actually be smart about where you put your hot water pipes (to a rad) under the floor and get a warm floor when the heating is on for next to no cost if you are moving pipes anyway.

I wouldn't bother putting in either (wet or electric) if it meant digging up a whole floor. I would only put them in a new build/extension.

We have it in our kitchen extension and it's fab. The dog loves sprawling out in it. We don't have it in the downstairs loo and the tiles are so cold.

For those who say the cost of electric underfloor heating is higher that’s not necessarily correct -

Running Costs
Underfloor Heating can offer substantially lower running costs compared to traditional central heating. This is because floor heating systems offer much quicker heat-up times than central-heating based systems whilst also running at lower temperatures yet still producing the same level of warmth in the room.
Running costs can vary depending on your home’s design, how well insulated it is, what energy tariff you are on and how you control and monitor your homes heating.
See our Running Costs Information Table below for examples of these running costs and use our Running Costs Calculator to get an idea of how much money you could save by installing Warmup heating in your home.
Running Costs Information Table
For these figures, we used an estimated energy price of 11.61p/kWh, using the heating system for 6 months (182 days) over the cooler months of the year on a 10mm Warmup Insulation Board. The average running cost after an initial heat-up period is 0.7836 p/m²/h.
ROOM TYPE HEATED AREA RUNNING TIME AM RUNNING TIME PM WINTER COST*
BATHROOM 4m² 2hrs 1hrs £22.75
KITCHEN 5m² 1hrs 2hrs £27.81
LOUNGE 15m² 0hrs 3hrs £78.19

www.warmup.co.uk/underfloor-heating/cost

I’m saying the cost of my electric UFH was high based on the bills I got when it was working, literally hundreds pm.

Who's getting 11p/kwh electricity? With the caps changing they are closer to 20p/kwh.

I also wouldn't necessarily trust the numbers provided by a company that sells electric UFH unless i could verify them elsewhere (fairly sure MSE or Which would offer ideas of cost).

If you have an EPC (mandatory in Scotland when selling not sure elsewhere), then it provides an estimate of your heating demand which could potentially allow you to do some educated guestimates of the differences in running costs. (But I am a spreadsheet loser who loves a comparison formula).

All that being said they do say electricity is the future (since it can be renewable) and O&G will be phased out (and when I say they I actually mean a major O&G company that I used to work for in a planning for the future global presentation).

Love, love, love ours. We had it put in when we had an extension done. Kitchen / dinning area and main bathroom have it and it's lovely to walk on in cold mornings. All connected to the central heating system and can be turned off with the rest of the heating come summer time. It also means that we have clean wall space because we don't have any radiators in the extension, which gives us more flexibility when arranging furniture.

@Muststopeating can you 'add' this Tado system to existing (probably old and crappy) radiators?
We're about to do an extension in which I hope to have wet UFH over engineered wood flooring, but the rest of the house will just have the existing rads. We're a big family, feel the cold/heat in different ways and are in/out of the house on v different schedules, so the system you describe sounds perfect (tho my husband will probably baulk at the cost).

@HBGKC yes, I believe its possible to retro fit to most radiators.

Ours are just the bog standard white ones, no idea how old but certainly not new and we had no problems installing them at all.

They are great for the most part and give me much better control over the heating and I'm fairly sure my oil costs have gone down a bit.

Downside is if your internet is on the blink it can be a bit tricky (though there are some manual work arounds) and I had once where it just wasn't turning off and I had to reboot the system.

I will definitely be expanding it when we add new radiators and the extension.

Also worth noting though that there are more suppliers that do wireless TRVs (thermostatic Radiator Valves)... though not as many as do wireless thermostats. I think possibly Hive and Heatmiser.

I should say there is a subscription option (a couple of quid a month) for Tado which I don't pay as it wouldn't be useful in our house. So don't let that put you off.

Wouldn't be without ours. Second house we have had with underfloor heating.

This one is a period property with solid stone walls and single-glazed windows and stone mullions (i.e. cold!) - but the underfloor heating makes it liveable. Would be even better with a better insulated property.

I would say that it works better with solid floors (well insulated underneath) and the heat transfer is not as good if you have a wooden floor over it.

Not having radiators is a big advantage.

Have you been anywhere that has it? I never saw the appeal until I did, it is such a pleasant heat.

QC16 these costs are high even though the pence per kWh is lower than it currently is. Pence per kWh has gone up.

My space heating bill for a 3 bed is around £400. According to the website you posted (which is bias by the way because they are in the business) it costs about £130 to heat just 24m square area. Factor in bedrooms and other areas and it sounds expensive or at least no cheaper. Plus you need to consider relative installation costs.

Do you need to top up your underfloor heating with radiators when it is particularly cold? If it takes a while to heat up is 2hrs on time enough to heat an area for long enough, say during the weekend?

Have it in our kitchen and bathroom.

Our electricity bill with the kitchen on was around £350pm - when we have it turned off it's £70pm.

Bathroom doesn't seem to work.

But apart from that it's great

I like it in the open plan kitchen diner, but as someone else said it does take a long time to heat up, but it has its own controls so we just had to do the timings right. Eg in the winter it’s on from 5-7am so that it’s nice when we are having breakfast and getting ready 7-8am and then it retains its heat quite well.
We have a ‘wet’ system so it’s basically like a giant radiator that connects into the system.
I understand that electric underfloor heating is cheaper to install but more expensive to run.
It is lovely having toasty hard floors but I don’t really miss it elsewhere, apart from in the bathroom maybe.
Radiators would’ve have been awkward and large to heat the open plan space.

Thanks @Muststopeating, that's very helpful.