House with underfloor heating - what to ask

pinkteapot

Viewing a house with underfloor heating. Never had it before. Nervous about it because in my head, if you have a leak/problem you have to dig your floor up?! Anyway, planning to ask:

- When was the system installed? (ie how old)
- Is it wet or electric?
- What are your gas/elec bills roughly? (vendor doing the viewing so they might know)

Anything else, or any tips on things to look out for?

letitbe90

Check that it is working? Not much else you can do.

maisie_cat

We have a whole ground floor water system, the pipe is pretty robust and if embedded in screed I can't see it leaking there. If there is going to be a leak it will most likely be at a joint with the manifold, but is no more likely than a leak at a joint in a traditional system. the only thing to remember is that it operates at a lower temp and takes longer to respond to changes in outside temperature. It is lovely to come down in the morning to a warm floor underfoot.
As an aside it also creates cat/dog trip hazards because they love the warm floor

G_M

Go onto the 'other energy' forum


https://forums.moneysavingexpert.com/forumdisplay.php?s=&daysprune=&f=78


read up on systems so you understand how they work/what can go wrong etc. Post a Q over there too.

AndyTails

pinkteapot wrote: »

Viewing a house with underfloor heating. Never had it before. Nervous about it because in my head, if you have a leak/problem you have to dig your floor up?! Anyway, planning to ask:

- When was the system installed? (ie how old)
- Is it wet or electric?
- What are your gas/elec bills roughly? (vendor doing the viewing so they might know)

Anything else, or any tips on things to look out for?

It's highly unlikely that they've done a whole house with electric underfloor heating. If they have - run! It'll be far too expensive to run. It's far more likely that it's wet.

There are two main system types that I can think of: screeded (where they fit the pipes and then pour concrete screed over it) or overlay (where they put panels above an existing floor and lay pipes in that, then just put e.g. wooden flooring over the top). If you get a leak in a screeded floor, then yes you'd need to dig up the concrete floor to replace the pipe. If you got a leak in an overlay system you'd have to lift the flooring to replace the pipe. But (and here's the important part) a leak is most likely at pipe connections, which will all be above ground. Ours are all in our under-stairs cupboard, the only thing that comes out of the cupboard are pipes, which are each continuous pipes from leaving the cupboard hot to returning cold. If you drill into your floor you might puncture a pipe, but otherwise it's pretty unlikely.

As far as tips go: underfloor heating is great! You get all the wall space back, as you don't have radiators, meaning there are far more ways to arrange furniture in a room. The temperature is much more even across a room, rather than hot near the radiator and cold elsewhere. It's supposedly more efficient as you heat the whole room to 22 degrees rather than heating to 35 degrees the air near the radiator and in a column above the radiator towards the ceiling, in order to achieve 22 degrees elsewhere. Oh, and you don't have a 60 degree radiator which can burn your fingers, you have a 25 degree floor instead.

The main downside is slow response time, and the expense of installing it. But the installation expense has already been done for you. The slow response time does mean that its recommended your overnight temperature is no more than 2 degrees colder than your day temperature; this sounds wasteful of energy to me. We run ours 4 degrees colder, and it seems to be ok.

pinkteapot

AndyTails wrote: »

It's highly unlikely that they've done a whole house with electric underfloor heating. If they have - run! It'll be far too expensive to run. It's far more likely that it's wet.

Yes - it's the whole house in a large 4-bed detached so hopefully it's wet!

AndyTails wrote: »

The main downside is slow response time, and the expense of installing it. But the installation expense has already been done for you. The slow response time does mean that its recommended your overnight temperature is no more than 2 degrees colder than your day temperature; this sounds wasteful of energy to me. We run ours 4 degrees colder, and it seems to be ok.

That suggests you run the heating 24/7? Isn't that really expensive?

We're used to standard boiler + radiators gas central heating, so only run the heating for an hour or two in the morning, plus a few hours in the evening, in winter.

We've relocated to the north (really north!) so heating costs are more of a concern than they used to be.

swindiff

Slow response times are no longer an issue with wet screed which can go down much thinner than the old traditional dry screed. The new wet screeds are also much more thermally conductive. I fitted underfloor heating myself using Gylvon Thermio Plus wet screed and could not be more pleased with it. You get a fantastic even heating throughout the room, nice warm feet and it warms up within about 30 minutes. None of this "you need to leave underfloor heating on constantly because it takes so long to get warm nonsense". It is also very efficient, our gas bills are about £25-£30/month for a 3 bed townhouse.

pinkteapot

Cheers! I can't tell how old the house is. There's no previous sold price for it as the current owner bought a plot and had a house designed and built. Vendor is doing the viewing so I'll ask about age of house and whether the underfloor heating is original or a recent installation. Vendor should also know what type of system it is as they had the house built.

You have all put my mind at rest about random leaks in the middle of the floor!

KiKi

I have underfloor heating in the basement of my house - it's electric. For one month I switched off central heating in that room and ran the underfloor. I found that a) I didn't realise how much a warm floor felt weird to me until I had it and I didn't like it; b) it was always too warm or not warm enough, and it felt like it took longer to heat up but then got too warm too quickly for me; c) my electricity bill went through the roof so economically it made no sense, and d) I forgot how useful warm radiators are to dry stuff out and all of a sudden I was having to dry clothes in other parts of the house.

Obviously, a) is a preference thing, b) might be an operational thing or my incompetence, and d) is a lifestyle thing. But until I tried underfloor heating I didn't think about what I liked, or how useful radiators are for how I use them, and I definitely wouldn't have it again.

Oh - and cats LOVE underfloor heating and soon become a trip hazard.

ProDave

If the vendor built the house then they should know all about it.

UFH is brilliant if done right. There are so many systems, but the most important question is how much insulation is UNDER the floor that is heated by UFH. Even a well insulated UFH system will lose perhaps 5% of it's heat, heating the ground under the house.

Find out the annual heating cost. Backed up by bills if possible.

Re warm up times, our heating is set to come on 2 hours before we get up. but it is also set to turn off 2 hours before we normally go to bed. Just as it takes a long time to warm up, it takes a long time to cool down. So it's just a different mindset you need.

Ah and at the risk of stating the obvious, DO NOT drill any holes in the floor.

The much more even temperatures, and total lack of radiators blocking walls, is the big bonus of UFH.

Continental

Oooh - when we lived in an apartment in Switzerland (Lake Zug, halfway between Zurich and Lucerne) the heating was wet system underfloor throughout; the living/dining room had a tiled floor as did the kitchen and bathrooms and the 3 bedrooms had wood parquet flooring. It was fabulous when I had to pop to the loo in the middle of the night and the floor was warm!

Oddly enough there was a radiator in the kitchen and another (remote controlled) radiator in the guest shower room, which we never turned on. There was also a chimney with a log fire in the living room but the apartment was so well insulated (triple glazed patio doors all along where a wall would normally be, to the full width balcony overlooking the beautiful lake) that we only used it a couple of times at Christmas to make the room look festive.

Many properties in the Swiss and French Alps - homes, hotels and office buildings - have underfloor heating. I love it and it’s a pity it’s so uncommon in the UK.